[TEST] rebase -r: let label generate safer labels
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One of the trickier aspects of the design of `git rebase --rebase-merges` is the way labels are generated for the initial todo list: those labels are supposed to be intuitive and first and foremost unique. To that end, `label_oid()` appends a unique suffix when necessary. Those labels not only need to be unique, but they also need to be valid refs. To make sure of that, `make_script_with_merges()` replaces whitespace by dashes. That would appear to be the wrong layer for that sanitizing step, though: all callers of `label_oid()` should get that same benefit. Even if it does not make a difference currently (the only called of `label_oid()` that passes a label that might need to be sanitized _is_ `make_script_with_merges()`), let's move the responsibility for sanitizing labels into the `label_oid()` function. This commit is best viewed with `-w` because it unfortunately needs to change the indentation of a large block of code in `label_oid()`. Signed-off-by: Johannes Schindelin <[email protected]>
The `label` todo command in interactive rebases creates temporary refs in the `refs/rewritten/` namespace. These refs are stored as loose refs, i.e. as files in `.git/refs/rewritten/`, therefore they have to conform with file name limitations on the current filesystem in addition to the accepted ref format. This poses a problem in particular on NTFS/FAT, where e.g. the colon, double-quote and pipe characters are disallowed as part of a file name. Let's safeguard against this by replacing not only white-space characters by dashes, but all non-alpha-numeric ones. However, we exempt non-ASCII UTF-8 characters from that, as it should be quite possible to reflect branch names such as `↯↯↯` in refs/file names. Signed-off-by: Matthew Rogers <[email protected]> Signed-off-by: Johannes Schindelin <[email protected]>
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/preview |
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Preview email sent as [email protected] |
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/submit |
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Submitted as [email protected] |
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/submit |
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Error: adc22c8 was already submitted |
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/submit |
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Submitted as [email protected] |
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/test |
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Received test 'undefined' |
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/testtest again |
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Received test 'again' |
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/test another time |
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Received test 'another time' |
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/test does it work still? |
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Received test 'does it work still?' |
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/test and yet another test |
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Received test 'and yet another test' |
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This branch is now known as |
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This patch series was integrated into pu via git@089c065. |
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This patch series was integrated into next via git@791d51b. |
dscho
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Feb 26, 2021
write_commit_graph initialises topo_levels using init_topo_level_slab(), next it calls compute_topological_levels() which can cause the slab to grow, we therefore need to clear the slab again using clear_topo_level_slab() when we're done. First introduced in 72a2bfc (commit-graph: add a slab to store topological levels, 2021-01-16). LeakSanitizer output: ==1026==ERROR: LeakSanitizer: detected memory leaks Direct leak of 8 byte(s) in 1 object(s) allocated from: #0 0x498ae9 in realloc /src/llvm-project/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3 #1 0xafbed8 in xrealloc /src/git/wrapper.c:126:8 #2 0x7966d1 in topo_level_slab_at_peek /src/git/commit-graph.c:71:1 #3 0x7965e0 in topo_level_slab_at /src/git/commit-graph.c:71:1 #4 0x78fbf5 in compute_topological_levels /src/git/commit-graph.c:1472:12 #5 0x78c5c3 in write_commit_graph /src/git/commit-graph.c:2456:2 #6 0x535c5f in graph_write /src/git/builtin/commit-graph.c:299:6 #7 0x5350ca in cmd_commit_graph /src/git/builtin/commit-graph.c:337:11 #8 0x4cddb1 in run_builtin /src/git/git.c:453:11 #9 0x4cabe2 in handle_builtin /src/git/git.c:704:3 #10 0x4cd084 in run_argv /src/git/git.c:771:4 #11 0x4ca424 in cmd_main /src/git/git.c:902:19 #12 0x707fb6 in main /src/git/common-main.c:52:11 #13 0x7fee4249383f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2083f) Indirect leak of 524256 byte(s) in 1 object(s) allocated from: #0 0x498942 in calloc /src/llvm-project/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3 #1 0xafc088 in xcalloc /src/git/wrapper.c:140:8 #2 0x796870 in topo_level_slab_at_peek /src/git/commit-graph.c:71:1 #3 0x7965e0 in topo_level_slab_at /src/git/commit-graph.c:71:1 #4 0x78fbf5 in compute_topological_levels /src/git/commit-graph.c:1472:12 #5 0x78c5c3 in write_commit_graph /src/git/commit-graph.c:2456:2 #6 0x535c5f in graph_write /src/git/builtin/commit-graph.c:299:6 #7 0x5350ca in cmd_commit_graph /src/git/builtin/commit-graph.c:337:11 #8 0x4cddb1 in run_builtin /src/git/git.c:453:11 #9 0x4cabe2 in handle_builtin /src/git/git.c:704:3 #10 0x4cd084 in run_argv /src/git/git.c:771:4 #11 0x4ca424 in cmd_main /src/git/git.c:902:19 #12 0x707fb6 in main /src/git/common-main.c:52:11 #13 0x7fee4249383f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2083f) SUMMARY: AddressSanitizer: 524264 byte(s) leaked in 2 allocation(s). Signed-off-by: Andrzej Hunt <[email protected]> Signed-off-by: Junio C Hamano <[email protected]>
dscho
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Mar 27, 2021
…sponse query_result can be be an empty strbuf (STRBUF_INIT) - in that case trying to read 3 bytes triggers a buffer overflow read (as query_result.buf = '\0'). Therefore we need to check query_result's length before trying to read 3 bytes. This overflow was introduced in: 940b94f (fsmonitor: log invocation of FSMonitor hook to trace2, 2021-02-03) It was found when running the test-suite against ASAN, and can be most easily reproduced with the following command: make GIT_TEST_OPTS="-v" DEFAULT_TEST_TARGET="t7519-status-fsmonitor.sh" \ SANITIZE=address DEVELOPER=1 test ==2235==ERROR: AddressSanitizer: global-buffer-overflow on address 0x0000019e6e5e at pc 0x00000043745c bp 0x7fffd382c520 sp 0x7fffd382bcc8 READ of size 3 at 0x0000019e6e5e thread T0 #0 0x43745b in MemcmpInterceptorCommon(void*, int (*)(void const*, void const*, unsigned long), void const*, void const*, unsigned long) /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/../sanitizer_common/sanitizer_common_interceptors.inc:842:7 #1 0x43786d in bcmp /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/../sanitizer_common/sanitizer_common_interceptors.inc:887:10 #2 0x80b146 in fsmonitor_is_trivial_response /home/ahunt/oss-fuzz/git/fsmonitor.c:192:10 #3 0x80b146 in query_fsmonitor /home/ahunt/oss-fuzz/git/fsmonitor.c:175:7 #4 0x80a749 in refresh_fsmonitor /home/ahunt/oss-fuzz/git/fsmonitor.c:267:21 #5 0x80bad1 in tweak_fsmonitor /home/ahunt/oss-fuzz/git/fsmonitor.c:429:4 #6 0x90f040 in read_index_from /home/ahunt/oss-fuzz/git/read-cache.c:2321:3 #7 0x8e5d08 in repo_read_index_preload /home/ahunt/oss-fuzz/git/preload-index.c:164:15 #8 0x52dd45 in prepare_index /home/ahunt/oss-fuzz/git/builtin/commit.c:363:6 #9 0x52a188 in cmd_commit /home/ahunt/oss-fuzz/git/builtin/commit.c:1588:15 #10 0x4ce77e in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11 #11 0x4ccb18 in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3 #12 0x4cb01c in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4 #13 0x4cb01c in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19 #14 0x6aca8d in main /home/ahunt/oss-fuzz/git/common-main.c:52:11 #15 0x7fb027bf5349 in __libc_start_main (/lib64/libc.so.6+0x24349) #16 0x4206b9 in _start /home/abuild/rpmbuild/BUILD/glibc-2.26/csu/../sysdeps/x86_64/start.S:120 0x0000019e6e5e is located 2 bytes to the left of global variable 'strbuf_slopbuf' defined in 'strbuf.c:51:6' (0x19e6e60) of size 1 'strbuf_slopbuf' is ascii string '' 0x0000019e6e5e is located 126 bytes to the right of global variable 'signals' defined in 'sigchain.c:11:31' (0x19e6be0) of size 512 SUMMARY: AddressSanitizer: global-buffer-overflow /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/../sanitizer_common/sanitizer_common_interceptors.inc:842:7 in MemcmpInterceptorCommon(void*, int (*)(void const*, void const*, unsigned long), void const*, void const*, unsigned long) Shadow bytes around the buggy address: 0x000080334d70: f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9 00 00 00 00 0x000080334d80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x000080334d90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x000080334da0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x000080334db0: 00 00 00 00 00 00 00 00 00 00 00 00 f9 f9 f9 f9 =>0x000080334dc0: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9[f9]01 f9 f9 f9 0x000080334dd0: f9 f9 f9 f9 03 f9 f9 f9 f9 f9 f9 f9 02 f9 f9 f9 0x000080334de0: f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9 04 f9 f9 f9 0x000080334df0: f9 f9 f9 f9 01 f9 f9 f9 f9 f9 f9 f9 00 00 00 00 0x000080334e00: f9 f9 f9 f9 00 00 00 00 f9 f9 f9 f9 01 f9 f9 f9 0x000080334e10: f9 f9 f9 f9 04 f9 f9 f9 f9 f9 f9 f9 00 f9 f9 f9 Shadow byte legend (one shadow byte represents 8 application bytes): Addressable: 00 Partially addressable: 01 02 03 04 05 06 07 Heap left redzone: fa Freed heap region: fd Stack left redzone: f1 Stack mid redzone: f2 Stack right redzone: f3 Stack after return: f5 Stack use after scope: f8 Global redzone: f9 Global init order: f6 Poisoned by user: f7 Container overflow: fc Array cookie: ac Intra object redzone: bb ASan internal: fe Left alloca redzone: ca Right alloca redzone: cb Shadow gap: cc Signed-off-by: Andrzej Hunt <[email protected]> Acked-by: Jeff Hostetler <[email protected]> Signed-off-by: Junio C Hamano <[email protected]>
dscho
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May 17, 2021
Most of these pointers can safely be freed when cmd_clone() completes, therefore we make sure to free them. The one exception is that we have to UNLEAK(repo) because it can point either to argv[0], or a malloc'd string returned by absolute_pathdup(). We also have to free(path) in the middle of cmd_clone(): later during cmd_clone(), path is unconditionally overwritten with a different path, triggering a leak. Freeing the first path immediately after use (but only in the case where it contains data) seems like the cleanest solution, as opposed to freeing it unconditionally before path is reused for another path. This leak appears to have been introduced in: f38aa83 (use local cloning if insteadOf makes a local URL, 2014-07-17) These leaks were found when running t0001 with LSAN, see also an excerpt of the LSAN output below (the full list is omitted because it's far too long, and mostly consists of indirect leakage of members of the refs we are freeing). Direct leak of 178 byte(s) in 1 object(s) allocated from: #0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3 #1 0x9a6ff4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8 #2 0x9a6fca in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9 #3 0x8ce296 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8 #4 0x8d2ebd in guess_remote_head /home/ahunt/oss-fuzz/git/remote.c:2215:10 #5 0x51d0c5 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1308:4 #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11 #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3 #8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4 #9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19 #10 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11 #11 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349) Direct leak of 165 byte(s) in 1 object(s) allocated from: #0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3 #1 0x9a6fc4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8 #2 0x9a6f9a in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9 #3 0x8ce266 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8 #4 0x51e9bd in wanted_peer_refs /home/ahunt/oss-fuzz/git/builtin/clone.c:574:21 #5 0x51cfe1 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1284:17 #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11 #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3 #8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4 #9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19 #10 0x69c42e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11 #11 0x7f8fef0c2349 in __libc_start_main (/lib64/libc.so.6+0x24349) Direct leak of 178 byte(s) in 1 object(s) allocated from: #0 0x49a53d in malloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3 #1 0x9a6ff4 in do_xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:41:8 #2 0x9a6fca in xmalloc /home/ahunt/oss-fuzz/git/wrapper.c:62:9 #3 0x8ce296 in copy_ref /home/ahunt/oss-fuzz/git/remote.c:885:8 #4 0x8d2ebd in guess_remote_head /home/ahunt/oss-fuzz/git/remote.c:2215:10 #5 0x51d0c5 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1308:4 #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11 #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3 #8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4 #9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19 #10 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11 #11 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349) Direct leak of 165 byte(s) in 1 object(s) allocated from: #0 0x49a6b2 in calloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3 #1 0x9a72f2 in xcalloc /home/ahunt/oss-fuzz/git/wrapper.c:140:8 #2 0x8ce203 in alloc_ref_with_prefix /home/ahunt/oss-fuzz/git/remote.c:867:20 #3 0x8ce1a2 in alloc_ref /home/ahunt/oss-fuzz/git/remote.c:875:9 #4 0x72f63e in process_ref_v2 /home/ahunt/oss-fuzz/git/connect.c:426:8 #5 0x72f21a in get_remote_refs /home/ahunt/oss-fuzz/git/connect.c:525:8 #6 0x979ab7 in handshake /home/ahunt/oss-fuzz/git/transport.c:305:4 #7 0x97872d in get_refs_via_connect /home/ahunt/oss-fuzz/git/transport.c:339:9 #8 0x9774b5 in transport_get_remote_refs /home/ahunt/oss-fuzz/git/transport.c:1388:4 #9 0x51cf80 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1271:9 #10 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11 #11 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3 #12 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4 #13 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19 #14 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11 #15 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349) Direct leak of 105 byte(s) in 1 object(s) allocated from: #0 0x49a859 in realloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3 #1 0x9a71f6 in xrealloc /home/ahunt/oss-fuzz/git/wrapper.c:126:8 #2 0x93622d in strbuf_grow /home/ahunt/oss-fuzz/git/strbuf.c:98:2 #3 0x937a73 in strbuf_addch /home/ahunt/oss-fuzz/git/./strbuf.h:231:3 #4 0x939fcd in strbuf_add_absolute_path /home/ahunt/oss-fuzz/git/strbuf.c:911:4 #5 0x69d3ce in absolute_pathdup /home/ahunt/oss-fuzz/git/abspath.c:261:2 #6 0x51c688 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1021:10 #7 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11 #8 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3 #9 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4 #10 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19 #11 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11 #12 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349) Signed-off-by: Andrzej Hunt <[email protected]> Signed-off-by: Junio C Hamano <[email protected]>
dscho
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repo_diff_setup() calls through to diff.c's static prep_parse_options(),
which in turn allocates a new array into diff_opts.parseopts.
diff_setup_done() is responsible for freeing that array, and has the
benefit of verifying diff_opts too - hence we add a call to
diff_setup_done() to avoid leaking parseopts.
Output from the leak as found while running t0090 with LSAN:
Direct leak of 7120 byte(s) in 1 object(s) allocated from:
#0 0x49a82d in malloc ../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
#1 0xa8bf89 in do_xmalloc wrapper.c:41:8
#2 0x7a7bae in prep_parse_options diff.c:5636:2
#3 0x7a7bae in repo_diff_setup diff.c:4611:2
#4 0x93716c in repo_index_has_changes read-cache.c:2518:3
#5 0x872233 in unclean merge-ort-wrappers.c:12:14
#6 0x872233 in merge_ort_recursive merge-ort-wrappers.c:53:6
#7 0x5d5b11 in try_merge_strategy builtin/merge.c:752:12
#8 0x5d0b6b in cmd_merge builtin/merge.c:1666:9
#9 0x4ce83e in run_builtin git.c:475:11
#10 0x4ccafe in handle_builtin git.c:729:3
#11 0x4cb01c in run_argv git.c:818:4
#12 0x4cb01c in cmd_main git.c:949:19
#13 0x6bdc2d in main common-main.c:52:11
#14 0x7f551eb51349 in __libc_start_main (/lib64/libc.so.6+0x24349)
SUMMARY: AddressSanitizer: 7120 byte(s) leaked in 1 allocation(s)
Signed-off-by: Andrzej Hunt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
dscho
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apply_multi_file_filter and async_query_available_blobs both query
subprocess output using subprocess_read_status, which writes data into
the identically named filter_status strbuf. We add a strbuf_release to
avoid leaking their contents.
Leak output seen when running t0021 with LSAN:
Direct leak of 24 byte(s) in 1 object(s) allocated from:
#0 0x49ab49 in realloc ../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
#1 0xa8c2b5 in xrealloc wrapper.c:126:8
#2 0x9ff99d in strbuf_grow strbuf.c:98:2
#3 0x9ff99d in strbuf_addbuf strbuf.c:304:2
#4 0xa101d6 in subprocess_read_status sub-process.c:45:5
#5 0x77793c in apply_multi_file_filter convert.c:886:8
#6 0x77793c in apply_filter convert.c:1042:10
#7 0x77a0b5 in convert_to_git_filter_fd convert.c:1492:7
#8 0x8b48cd in index_stream_convert_blob object-file.c:2156:2
#9 0x8b48cd in index_fd object-file.c:2248:9
#10 0x597411 in hash_fd builtin/hash-object.c:43:9
#11 0x596be1 in hash_object builtin/hash-object.c:59:2
#12 0x596be1 in cmd_hash_object builtin/hash-object.c:153:3
#13 0x4ce83e in run_builtin git.c:475:11
#14 0x4ccafe in handle_builtin git.c:729:3
#15 0x4cb01c in run_argv git.c:818:4
#16 0x4cb01c in cmd_main git.c:949:19
#17 0x6bdc2d in main common-main.c:52:11
#18 0x7f42acf79349 in __libc_start_main (/lib64/libc.so.6+0x24349)
SUMMARY: AddressSanitizer: 24 byte(s) leaked in 1 allocation(s).
Direct leak of 120 byte(s) in 5 object(s) allocated from:
#0 0x49ab49 in realloc ../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
#1 0xa8c295 in xrealloc wrapper.c:126:8
#2 0x9ff97d in strbuf_grow strbuf.c:98:2
#3 0x9ff97d in strbuf_addbuf strbuf.c:304:2
#4 0xa101b6 in subprocess_read_status sub-process.c:45:5
#5 0x775c73 in async_query_available_blobs convert.c:960:8
#6 0x80029d in finish_delayed_checkout entry.c:183:9
#7 0xa65d1e in check_updates unpack-trees.c:493:10
#8 0xa5f469 in unpack_trees unpack-trees.c:1747:8
#9 0x525971 in checkout builtin/clone.c:815:6
#10 0x525971 in cmd_clone builtin/clone.c:1409:8
#11 0x4ce83e in run_builtin git.c:475:11
#12 0x4ccafe in handle_builtin git.c:729:3
#13 0x4cb01c in run_argv git.c:818:4
#14 0x4cb01c in cmd_main git.c:949:19
#15 0x6bdc2d in main common-main.c:52:11
#16 0x7fa253fce349 in __libc_start_main (/lib64/libc.so.6+0x24349)
SUMMARY: AddressSanitizer: 120 byte(s) leaked in 5 allocation(s).
Signed-off-by: Andrzej Hunt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
dscho
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These leaks all happen at the end of cmd_mv, hence don't matter in any
way. But we still fix the easy ones and squash the rest to get us closer
to being able to run tests without leaks.
LSAN output from t0050:
Direct leak of 384 byte(s) in 1 object(s) allocated from:
#0 0x49ab49 in realloc ../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
#1 0xa8c015 in xrealloc wrapper.c:126:8
#2 0xa0a7e1 in add_entry string-list.c:44:2
#3 0xa0a7e1 in string_list_insert string-list.c:58:14
#4 0x5dac03 in cmd_mv builtin/mv.c:248:4
#5 0x4ce83e in run_builtin git.c:475:11
#6 0x4ccafe in handle_builtin git.c:729:3
#7 0x4cb01c in run_argv git.c:818:4
#8 0x4cb01c in cmd_main git.c:949:19
#9 0x6bd9ad in main common-main.c:52:11
#10 0x7fbfeffc4349 in __libc_start_main (/lib64/libc.so.6+0x24349)
Direct leak of 16 byte(s) in 1 object(s) allocated from:
#0 0x49a82d in malloc ../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
#1 0xa8bd09 in do_xmalloc wrapper.c:41:8
#2 0x5dbc34 in internal_prefix_pathspec builtin/mv.c:32:2
#3 0x5da575 in cmd_mv builtin/mv.c:158:14
#4 0x4ce83e in run_builtin git.c:475:11
#5 0x4ccafe in handle_builtin git.c:729:3
#6 0x4cb01c in run_argv git.c:818:4
#7 0x4cb01c in cmd_main git.c:949:19
#8 0x6bd9ad in main common-main.c:52:11
#9 0x7fbfeffc4349 in __libc_start_main (/lib64/libc.so.6+0x24349)
Direct leak of 16 byte(s) in 1 object(s) allocated from:
#0 0x49a82d in malloc ../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
#1 0xa8bd09 in do_xmalloc wrapper.c:41:8
#2 0x5dbc34 in internal_prefix_pathspec builtin/mv.c:32:2
#3 0x5da4e4 in cmd_mv builtin/mv.c:148:11
#4 0x4ce83e in run_builtin git.c:475:11
#5 0x4ccafe in handle_builtin git.c:729:3
#6 0x4cb01c in run_argv git.c:818:4
#7 0x4cb01c in cmd_main git.c:949:19
#8 0x6bd9ad in main common-main.c:52:11
#9 0x7fbfeffc4349 in __libc_start_main (/lib64/libc.so.6+0x24349)
Direct leak of 8 byte(s) in 1 object(s) allocated from:
#0 0x49a9a2 in calloc ../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3
#1 0xa8c119 in xcalloc wrapper.c:140:8
#2 0x5da585 in cmd_mv builtin/mv.c:159:22
#3 0x4ce83e in run_builtin git.c:475:11
#4 0x4ccafe in handle_builtin git.c:729:3
#5 0x4cb01c in run_argv git.c:818:4
#6 0x4cb01c in cmd_main git.c:949:19
#7 0x6bd9ad in main common-main.c:52:11
#8 0x7fbfeffc4349 in __libc_start_main (/lib64/libc.so.6+0x24349)
Direct leak of 4 byte(s) in 1 object(s) allocated from:
#0 0x49a9a2 in calloc ../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3
#1 0xa8c119 in xcalloc wrapper.c:140:8
#2 0x5da4f8 in cmd_mv builtin/mv.c:149:10
#3 0x4ce83e in run_builtin git.c:475:11
#4 0x4ccafe in handle_builtin git.c:729:3
#5 0x4cb01c in run_argv git.c:818:4
#6 0x4cb01c in cmd_main git.c:949:19
#7 0x6bd9ad in main common-main.c:52:11
#8 0x7fbfeffc4349 in __libc_start_main (/lib64/libc.so.6+0x24349)
Indirect leak of 65 byte(s) in 1 object(s) allocated from:
#0 0x49ab49 in realloc ../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
#1 0xa8c015 in xrealloc wrapper.c:126:8
#2 0xa00226 in strbuf_grow strbuf.c:98:2
#3 0xa00226 in strbuf_vaddf strbuf.c:394:3
#4 0xa065c7 in xstrvfmt strbuf.c:981:2
#5 0xa065c7 in xstrfmt strbuf.c:991:8
#6 0x9e7ce7 in prefix_path_gently setup.c:115:15
#7 0x9e7fa6 in prefix_path setup.c:128:12
#8 0x5dbdbf in internal_prefix_pathspec builtin/mv.c:55:23
#9 0x5da575 in cmd_mv builtin/mv.c:158:14
#10 0x4ce83e in run_builtin git.c:475:11
#11 0x4ccafe in handle_builtin git.c:729:3
#12 0x4cb01c in run_argv git.c:818:4
#13 0x4cb01c in cmd_main git.c:949:19
#14 0x6bd9ad in main common-main.c:52:11
#15 0x7fbfeffc4349 in __libc_start_main (/lib64/libc.so.6+0x24349)
Indirect leak of 65 byte(s) in 1 object(s) allocated from:
#0 0x49ab49 in realloc ../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
#1 0xa8c015 in xrealloc wrapper.c:126:8
#2 0xa00226 in strbuf_grow strbuf.c:98:2
#3 0xa00226 in strbuf_vaddf strbuf.c:394:3
#4 0xa065c7 in xstrvfmt strbuf.c:981:2
#5 0xa065c7 in xstrfmt strbuf.c:991:8
#6 0x9e7ce7 in prefix_path_gently setup.c:115:15
#7 0x9e7fa6 in prefix_path setup.c:128:12
#8 0x5dbdbf in internal_prefix_pathspec builtin/mv.c:55:23
#9 0x5da4e4 in cmd_mv builtin/mv.c:148:11
#10 0x4ce83e in run_builtin git.c:475:11
#11 0x4ccafe in handle_builtin git.c:729:3
#12 0x4cb01c in run_argv git.c:818:4
#13 0x4cb01c in cmd_main git.c:949:19
#14 0x6bd9ad in main common-main.c:52:11
#15 0x7fbfeffc4349 in __libc_start_main (/lib64/libc.so.6+0x24349)
SUMMARY: AddressSanitizer: 558 byte(s) leaked in 7 allocation(s).
Signed-off-by: Andrzej Hunt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
dscho
pushed a commit
that referenced
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Jul 29, 2021
merge_name() calls dwim_ref(), which allocates a new string into
found_ref. Therefore add a free() to avoid leaking found_ref.
LSAN output from t0021:
Direct leak of 16 byte(s) in 1 object(s) allocated from:
#0 0x486804 in strdup ../projects/compiler-rt/lib/asan/asan_interceptors.cpp:452:3
#1 0xa8beb8 in xstrdup wrapper.c:29:14
#2 0x954054 in expand_ref refs.c:671:12
#3 0x953cb6 in repo_dwim_ref refs.c:644:22
#4 0x5d3759 in dwim_ref refs.h:162:9
#5 0x5d3759 in merge_name builtin/merge.c:517:6
#6 0x5d3759 in collect_parents builtin/merge.c:1214:5
#7 0x5cf60d in cmd_merge builtin/merge.c:1458:16
#8 0x4ce83e in run_builtin git.c:475:11
#9 0x4ccafe in handle_builtin git.c:729:3
#10 0x4cb01c in run_argv git.c:818:4
#11 0x4cb01c in cmd_main git.c:949:19
#12 0x6bdbfd in main common-main.c:52:11
#13 0x7f0430502349 in __libc_start_main (/lib64/libc.so.6+0x24349)
SUMMARY: AddressSanitizer: 16 byte(s) leaked in 1 allocation(s).
Signed-off-by: Andrzej Hunt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
dscho
pushed a commit
that referenced
this pull request
Jul 29, 2021
setup_unpack_trees_porcelain() populates various fields on
unpack_tree_opts, we need to call clear_unpack_trees_porcelain() to
avoid leaking them. Specifically, we used to leak
unpack_tree_opts.msgs_to_free.
We have to do this in leave_reset_head because there are multiple
scenarios where unpack_tree_opts has already been configured, followed
by a 'goto leave_reset_head'. But we can also 'goto leave_reset_head'
prior to having initialised unpack_tree_opts via memset(..., 0, ...).
Therefore we also move unpack_tree_opts initialisation to the start of
reset_head(), and convert it to use brace initialisation - which
guarantees that we can never clear an uninitialised unpack_tree_opts.
clear_unpack_tree_opts() is always safe to call as long as
unpack_tree_opts is at least zero-initialised, i.e. it does not depend
on a previous call to setup_unpack_trees_porcelain().
LSAN output from t0021:
Direct leak of 192 byte(s) in 1 object(s) allocated from:
#0 0x49ab49 in realloc ../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
#1 0xa721e5 in xrealloc wrapper.c:126:8
#2 0x9f7861 in strvec_push_nodup strvec.c:19:2
#3 0x9f7861 in strvec_pushf strvec.c:39:2
#4 0xa43e14 in setup_unpack_trees_porcelain unpack-trees.c:129:3
#5 0x97e011 in reset_head reset.c:53:2
#6 0x61dfa5 in cmd_rebase builtin/rebase.c:1991:9
#7 0x4ce83e in run_builtin git.c:475:11
#8 0x4ccafe in handle_builtin git.c:729:3
#9 0x4cb01c in run_argv git.c:818:4
#10 0x4cb01c in cmd_main git.c:949:19
#11 0x6b3f3d in main common-main.c:52:11
#12 0x7fa8addf3349 in __libc_start_main (/lib64/libc.so.6+0x24349)
Indirect leak of 147 byte(s) in 1 object(s) allocated from:
#0 0x49ab49 in realloc ../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
#1 0xa721e5 in xrealloc wrapper.c:126:8
#2 0x9e8d54 in strbuf_grow strbuf.c:98:2
#3 0x9e8d54 in strbuf_vaddf strbuf.c:401:3
#4 0x9f7774 in strvec_pushf strvec.c:36:2
#5 0xa43e14 in setup_unpack_trees_porcelain unpack-trees.c:129:3
#6 0x97e011 in reset_head reset.c:53:2
#7 0x61dfa5 in cmd_rebase builtin/rebase.c:1991:9
#8 0x4ce83e in run_builtin git.c:475:11
#9 0x4ccafe in handle_builtin git.c:729:3
#10 0x4cb01c in run_argv git.c:818:4
#11 0x4cb01c in cmd_main git.c:949:19
#12 0x6b3f3d in main common-main.c:52:11
#13 0x7fa8addf3349 in __libc_start_main (/lib64/libc.so.6+0x24349)
Indirect leak of 134 byte(s) in 1 object(s) allocated from:
#0 0x49ab49 in realloc ../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
#1 0xa721e5 in xrealloc wrapper.c:126:8
#2 0x9e8d54 in strbuf_grow strbuf.c:98:2
#3 0x9e8d54 in strbuf_vaddf strbuf.c:401:3
#4 0x9f7774 in strvec_pushf strvec.c:36:2
#5 0xa43fe4 in setup_unpack_trees_porcelain unpack-trees.c:168:3
#6 0x97e011 in reset_head reset.c:53:2
#7 0x61dfa5 in cmd_rebase builtin/rebase.c:1991:9
#8 0x4ce83e in run_builtin git.c:475:11
#9 0x4ccafe in handle_builtin git.c:729:3
#10 0x4cb01c in run_argv git.c:818:4
#11 0x4cb01c in cmd_main git.c:949:19
#12 0x6b3f3d in main common-main.c:52:11
#13 0x7fa8addf3349 in __libc_start_main (/lib64/libc.so.6+0x24349)
Indirect leak of 130 byte(s) in 1 object(s) allocated from:
#0 0x49ab49 in realloc ../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
#1 0xa721e5 in xrealloc wrapper.c:126:8
#2 0x9e8d54 in strbuf_grow strbuf.c:98:2
#3 0x9e8d54 in strbuf_vaddf strbuf.c:401:3
#4 0x9f7774 in strvec_pushf strvec.c:36:2
#5 0xa43f20 in setup_unpack_trees_porcelain unpack-trees.c:150:3
#6 0x97e011 in reset_head reset.c:53:2
#7 0x61dfa5 in cmd_rebase builtin/rebase.c:1991:9
#8 0x4ce83e in run_builtin git.c:475:11
#9 0x4ccafe in handle_builtin git.c:729:3
#10 0x4cb01c in run_argv git.c:818:4
#11 0x4cb01c in cmd_main git.c:949:19
#12 0x6b3f3d in main common-main.c:52:11
#13 0x7fa8addf3349 in __libc_start_main (/lib64/libc.so.6+0x24349)
SUMMARY: AddressSanitizer: 603 byte(s) leaked in 4 allocation(s).
Signed-off-by: Andrzej Hunt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
dscho
pushed a commit
that referenced
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Oct 27, 2021
In a sparse index it is possible for the tree that is being verified
to be freed while it is being verified. This happens when the index is
sparse but the cache tree is not and index_name_pos() looks up a path
from the cache tree that is a descendant of a sparse index entry. That
triggers a call to ensure_full_index() which frees the cache tree that
is being verified. Carrying on trying to verify the tree after this
results in a use-after-free bug. Instead restart the verification if a
sparse index is converted to a full index. This bug is triggered by a
call to reset_head() in "git rebase --apply". Thanks to René Scharfe
and Derrick Stolee for their help analyzing the problem.
==74345==ERROR: AddressSanitizer: heap-use-after-free on address 0x606000001b20 at pc 0x557cbe82d3a2 bp 0x7ffdfee08090 sp 0x7ffdfee08080
READ of size 4 at 0x606000001b20 thread T0
#0 0x557cbe82d3a1 in verify_one /home/phil/src/git/cache-tree.c:863
#1 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840
#2 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840
#3 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840
#4 0x557cbe830a2b in cache_tree_verify /home/phil/src/git/cache-tree.c:910
#5 0x557cbea53741 in write_locked_index /home/phil/src/git/read-cache.c:3250
#6 0x557cbeab7fdd in reset_head /home/phil/src/git/reset.c:87
#7 0x557cbe72147f in cmd_rebase builtin/rebase.c:2074
#8 0x557cbe5bd151 in run_builtin /home/phil/src/git/git.c:461
#9 0x557cbe5bd151 in handle_builtin /home/phil/src/git/git.c:714
#10 0x557cbe5c0503 in run_argv /home/phil/src/git/git.c:781
#11 0x557cbe5c0503 in cmd_main /home/phil/src/git/git.c:912
#12 0x557cbe5bad28 in main /home/phil/src/git/common-main.c:52
#13 0x7fdd4b82eb24 in __libc_start_main (/usr/lib/libc.so.6+0x27b24)
#14 0x557cbe5bcb8d in _start (/home/phil/src/git/git+0x1b9b8d)
0x606000001b20 is located 0 bytes inside of 56-byte region [0x606000001b20,0x606000001b58)
freed by thread T0 here:
#0 0x7fdd4bacff19 in __interceptor_free /build/gcc/src/gcc/libsanitizer/asan/asan_malloc_linux.cpp:127
#1 0x557cbe82af60 in cache_tree_free /home/phil/src/git/cache-tree.c:35
#2 0x557cbe82aee5 in cache_tree_free /home/phil/src/git/cache-tree.c:31
#3 0x557cbe82aee5 in cache_tree_free /home/phil/src/git/cache-tree.c:31
#4 0x557cbe82aee5 in cache_tree_free /home/phil/src/git/cache-tree.c:31
#5 0x557cbeb2557a in ensure_full_index /home/phil/src/git/sparse-index.c:310
#6 0x557cbea45c4a in index_name_stage_pos /home/phil/src/git/read-cache.c:588
#7 0x557cbe82ce37 in verify_one /home/phil/src/git/cache-tree.c:850
#8 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840
#9 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840
#10 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840
#11 0x557cbe830a2b in cache_tree_verify /home/phil/src/git/cache-tree.c:910
#12 0x557cbea53741 in write_locked_index /home/phil/src/git/read-cache.c:3250
#13 0x557cbeab7fdd in reset_head /home/phil/src/git/reset.c:87
#14 0x557cbe72147f in cmd_rebase builtin/rebase.c:2074
#15 0x557cbe5bd151 in run_builtin /home/phil/src/git/git.c:461
#16 0x557cbe5bd151 in handle_builtin /home/phil/src/git/git.c:714
#17 0x557cbe5c0503 in run_argv /home/phil/src/git/git.c:781
#18 0x557cbe5c0503 in cmd_main /home/phil/src/git/git.c:912
#19 0x557cbe5bad28 in main /home/phil/src/git/common-main.c:52
#20 0x7fdd4b82eb24 in __libc_start_main (/usr/lib/libc.so.6+0x27b24)
previously allocated by thread T0 here:
#0 0x7fdd4bad0459 in __interceptor_calloc /build/gcc/src/gcc/libsanitizer/asan/asan_malloc_linux.cpp:154
#1 0x557cbebc1807 in xcalloc /home/phil/src/git/wrapper.c:140
#2 0x557cbe82b7d8 in cache_tree /home/phil/src/git/cache-tree.c:17
#3 0x557cbe82b7d8 in prime_cache_tree_rec /home/phil/src/git/cache-tree.c:763
#4 0x557cbe82b837 in prime_cache_tree_rec /home/phil/src/git/cache-tree.c:764
#5 0x557cbe82b837 in prime_cache_tree_rec /home/phil/src/git/cache-tree.c:764
#6 0x557cbe8304e1 in prime_cache_tree /home/phil/src/git/cache-tree.c:779
#7 0x557cbeab7fa7 in reset_head /home/phil/src/git/reset.c:85
#8 0x557cbe72147f in cmd_rebase builtin/rebase.c:2074
#9 0x557cbe5bd151 in run_builtin /home/phil/src/git/git.c:461
#10 0x557cbe5bd151 in handle_builtin /home/phil/src/git/git.c:714
#11 0x557cbe5c0503 in run_argv /home/phil/src/git/git.c:781
#12 0x557cbe5c0503 in cmd_main /home/phil/src/git/git.c:912
#13 0x557cbe5bad28 in main /home/phil/src/git/common-main.c:52
#14 0x7fdd4b82eb24 in __libc_start_main (/usr/lib/libc.so.6+0x27b24)
Signed-off-by: Phillip Wood <[email protected]>
Signed-off-by: Derrick Stolee <[email protected]>
dscho
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Oct 27, 2021
When I was playing around with trace2 data and creating flamegraphs, I tried a `git fetch` call to see how the `git-remote-https` command would show up. What I didn't expect was an `ensure_full_index()` region! It turns out that `git fetch` and `git pull` need to check the index for a `.gitmodules` file to see if it should recurse into any submodules. Here is the stack trace from a debugger: ``` #0 ensure_full_index (istate=0x555555ac1c80 <the_index>) at sparse-index.c:404 #1 0x000055555571a979 in do_read_index (istate=istate@entry=0x555555ac1c80 <the_index>, path=path@entry=0x555555ad7b90 ".git/index", must_exist=must_exist@entry=0) at read-cache.c:2386 #2 0x000055555571eb7d in do_read_index (must_exist=0, path=0x555555ad7b90 ".git/index", istate=0x555555ac1c80 <the_index>) at hash.h:244 #3 read_index_from (istate=0x555555ac1c80 <the_index>, path=0x555555ad7b90 ".git/index", gitdir=0x555555ad7b30 ".git") at read-cache.c:2426 #4 0x000055555573f4c2 in repo_read_index (repo=repo@entry=0x555555ac1da0 <the_repo>) at repository.c:286 #5 0x00005555556f14d0 in get_oid_with_context_1 (repo=repo@entry=0x555555ac1da0 <the_repo>, name=name@entry=0x55555582c022 ":.gitmodules", flags=flags@entry=0, prefix=prefix@entry=0x0, oid=oid@entry=0x7fffffffdb00, oc=oc@entry=0x7fffffffda70) at object-name.c:1850 #6 0x00005555556f1f53 in get_oid_with_context (oc=0x7fffffffda70, oid=0x7fffffffdb00, flags=0, str=0x55555582c022 ":.gitmodules", repo=0x555555ac1da0 <the_repo>) at object-name.c:1947 #7 repo_get_oid (r=r@entry=0x555555ac1da0 <the_repo>, name=name@entry=0x55555582c022 ":.gitmodules", oid=oid@entry=0x7fffffffdb00) at object-name.c:1603 #8 0x000055555577330f in config_from_gitmodules (fn=fn@entry=0x555555773460 <gitmodules_fetch_config>, repo=0x555555ac1da0 <the_repo>, data=data@entry=0x7fffffffdb60) at submodule-config.c:650 #9 0x000055555577462d in config_from_gitmodules (data=0x7fffffffdb60, repo=<optimized out>, fn=0x555555773460 <gitmodules_fetch_config>) at submodule-config.c:638 #10 fetch_config_from_gitmodules (max_children=<optimized out>, recurse_submodules=<optimized out>) at submodule-config.c:800 #11 0x00005555555b9e41 in cmd_fetch (argc=1, argv=0x7fffffffe090, prefix=0x0) at builtin/fetch.c:1999 #12 0x0000555555573ff6 in run_builtin (argv=<optimized out>, argc=<optimized out>, p=<optimized out>) at git.c:528 #13 handle_builtin (argc=<optimized out>, argv=<optimized out>) at git.c:785 #14 0x000055555557528c in run_argv (argv=0x7fffffffddf0, argcp=0x7fffffffddfc) at git.c:857 #15 cmd_main (argc=<optimized out>, argv=<optimized out>) at git.c:993 #16 0x0000555555573ac8 in main (argc=3, argv=0x7fffffffe088) at common-main.c:52 ``` The operations these commands use are guarded by items such as `index_name_pos()` and others. Since the `.gitmodules` file is always at root, we would not need to expand, anyway.
dscho
pushed a commit
that referenced
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Nov 2, 2021
In a sparse index it is possible for the tree that is being verified
to be freed while it is being verified. This happens when the index is
sparse but the cache tree is not and index_name_pos() looks up a path
from the cache tree that is a descendant of a sparse index entry. That
triggers a call to ensure_full_index() which frees the cache tree that
is being verified. Carrying on trying to verify the tree after this
results in a use-after-free bug. Instead restart the verification if a
sparse index is converted to a full index. This bug is triggered by a
call to reset_head() in "git rebase --apply". Thanks to René Scharfe
and Derrick Stolee for their help analyzing the problem.
==74345==ERROR: AddressSanitizer: heap-use-after-free on address 0x606000001b20 at pc 0x557cbe82d3a2 bp 0x7ffdfee08090 sp 0x7ffdfee08080
READ of size 4 at 0x606000001b20 thread T0
#0 0x557cbe82d3a1 in verify_one /home/phil/src/git/cache-tree.c:863
#1 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840
#2 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840
#3 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840
#4 0x557cbe830a2b in cache_tree_verify /home/phil/src/git/cache-tree.c:910
#5 0x557cbea53741 in write_locked_index /home/phil/src/git/read-cache.c:3250
#6 0x557cbeab7fdd in reset_head /home/phil/src/git/reset.c:87
#7 0x557cbe72147f in cmd_rebase builtin/rebase.c:2074
#8 0x557cbe5bd151 in run_builtin /home/phil/src/git/git.c:461
#9 0x557cbe5bd151 in handle_builtin /home/phil/src/git/git.c:714
#10 0x557cbe5c0503 in run_argv /home/phil/src/git/git.c:781
#11 0x557cbe5c0503 in cmd_main /home/phil/src/git/git.c:912
#12 0x557cbe5bad28 in main /home/phil/src/git/common-main.c:52
#13 0x7fdd4b82eb24 in __libc_start_main (/usr/lib/libc.so.6+0x27b24)
#14 0x557cbe5bcb8d in _start (/home/phil/src/git/git+0x1b9b8d)
0x606000001b20 is located 0 bytes inside of 56-byte region [0x606000001b20,0x606000001b58)
freed by thread T0 here:
#0 0x7fdd4bacff19 in __interceptor_free /build/gcc/src/gcc/libsanitizer/asan/asan_malloc_linux.cpp:127
#1 0x557cbe82af60 in cache_tree_free /home/phil/src/git/cache-tree.c:35
#2 0x557cbe82aee5 in cache_tree_free /home/phil/src/git/cache-tree.c:31
#3 0x557cbe82aee5 in cache_tree_free /home/phil/src/git/cache-tree.c:31
#4 0x557cbe82aee5 in cache_tree_free /home/phil/src/git/cache-tree.c:31
#5 0x557cbeb2557a in ensure_full_index /home/phil/src/git/sparse-index.c:310
#6 0x557cbea45c4a in index_name_stage_pos /home/phil/src/git/read-cache.c:588
#7 0x557cbe82ce37 in verify_one /home/phil/src/git/cache-tree.c:850
#8 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840
#9 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840
#10 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840
#11 0x557cbe830a2b in cache_tree_verify /home/phil/src/git/cache-tree.c:910
#12 0x557cbea53741 in write_locked_index /home/phil/src/git/read-cache.c:3250
#13 0x557cbeab7fdd in reset_head /home/phil/src/git/reset.c:87
#14 0x557cbe72147f in cmd_rebase builtin/rebase.c:2074
#15 0x557cbe5bd151 in run_builtin /home/phil/src/git/git.c:461
#16 0x557cbe5bd151 in handle_builtin /home/phil/src/git/git.c:714
#17 0x557cbe5c0503 in run_argv /home/phil/src/git/git.c:781
#18 0x557cbe5c0503 in cmd_main /home/phil/src/git/git.c:912
#19 0x557cbe5bad28 in main /home/phil/src/git/common-main.c:52
#20 0x7fdd4b82eb24 in __libc_start_main (/usr/lib/libc.so.6+0x27b24)
previously allocated by thread T0 here:
#0 0x7fdd4bad0459 in __interceptor_calloc /build/gcc/src/gcc/libsanitizer/asan/asan_malloc_linux.cpp:154
#1 0x557cbebc1807 in xcalloc /home/phil/src/git/wrapper.c:140
#2 0x557cbe82b7d8 in cache_tree /home/phil/src/git/cache-tree.c:17
#3 0x557cbe82b7d8 in prime_cache_tree_rec /home/phil/src/git/cache-tree.c:763
#4 0x557cbe82b837 in prime_cache_tree_rec /home/phil/src/git/cache-tree.c:764
#5 0x557cbe82b837 in prime_cache_tree_rec /home/phil/src/git/cache-tree.c:764
#6 0x557cbe8304e1 in prime_cache_tree /home/phil/src/git/cache-tree.c:779
#7 0x557cbeab7fa7 in reset_head /home/phil/src/git/reset.c:85
#8 0x557cbe72147f in cmd_rebase builtin/rebase.c:2074
#9 0x557cbe5bd151 in run_builtin /home/phil/src/git/git.c:461
#10 0x557cbe5bd151 in handle_builtin /home/phil/src/git/git.c:714
#11 0x557cbe5c0503 in run_argv /home/phil/src/git/git.c:781
#12 0x557cbe5c0503 in cmd_main /home/phil/src/git/git.c:912
#13 0x557cbe5bad28 in main /home/phil/src/git/common-main.c:52
#14 0x7fdd4b82eb24 in __libc_start_main (/usr/lib/libc.so.6+0x27b24)
Signed-off-by: Phillip Wood <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
dscho
pushed a commit
that referenced
this pull request
Nov 10, 2021
When I was playing around with trace2 data and creating flamegraphs, I tried a `git fetch` call to see how the `git-remote-https` command would show up. What I didn't expect was an `ensure_full_index()` region! It turns out that `git fetch` and `git pull` need to check the index for a `.gitmodules` file to see if it should recurse into any submodules. Here is the stack trace from a debugger: ``` #0 ensure_full_index (istate=0x555555ac1c80 <the_index>) at sparse-index.c:404 #1 0x000055555571a979 in do_read_index (istate=istate@entry=0x555555ac1c80 <the_index>, path=path@entry=0x555555ad7b90 ".git/index", must_exist=must_exist@entry=0) at read-cache.c:2386 #2 0x000055555571eb7d in do_read_index (must_exist=0, path=0x555555ad7b90 ".git/index", istate=0x555555ac1c80 <the_index>) at hash.h:244 #3 read_index_from (istate=0x555555ac1c80 <the_index>, path=0x555555ad7b90 ".git/index", gitdir=0x555555ad7b30 ".git") at read-cache.c:2426 #4 0x000055555573f4c2 in repo_read_index (repo=repo@entry=0x555555ac1da0 <the_repo>) at repository.c:286 #5 0x00005555556f14d0 in get_oid_with_context_1 (repo=repo@entry=0x555555ac1da0 <the_repo>, name=name@entry=0x55555582c022 ":.gitmodules", flags=flags@entry=0, prefix=prefix@entry=0x0, oid=oid@entry=0x7fffffffdb00, oc=oc@entry=0x7fffffffda70) at object-name.c:1850 #6 0x00005555556f1f53 in get_oid_with_context (oc=0x7fffffffda70, oid=0x7fffffffdb00, flags=0, str=0x55555582c022 ":.gitmodules", repo=0x555555ac1da0 <the_repo>) at object-name.c:1947 #7 repo_get_oid (r=r@entry=0x555555ac1da0 <the_repo>, name=name@entry=0x55555582c022 ":.gitmodules", oid=oid@entry=0x7fffffffdb00) at object-name.c:1603 #8 0x000055555577330f in config_from_gitmodules (fn=fn@entry=0x555555773460 <gitmodules_fetch_config>, repo=0x555555ac1da0 <the_repo>, data=data@entry=0x7fffffffdb60) at submodule-config.c:650 #9 0x000055555577462d in config_from_gitmodules (data=0x7fffffffdb60, repo=<optimized out>, fn=0x555555773460 <gitmodules_fetch_config>) at submodule-config.c:638 #10 fetch_config_from_gitmodules (max_children=<optimized out>, recurse_submodules=<optimized out>) at submodule-config.c:800 #11 0x00005555555b9e41 in cmd_fetch (argc=1, argv=0x7fffffffe090, prefix=0x0) at builtin/fetch.c:1999 #12 0x0000555555573ff6 in run_builtin (argv=<optimized out>, argc=<optimized out>, p=<optimized out>) at git.c:528 #13 handle_builtin (argc=<optimized out>, argv=<optimized out>) at git.c:785 #14 0x000055555557528c in run_argv (argv=0x7fffffffddf0, argcp=0x7fffffffddfc) at git.c:857 #15 cmd_main (argc=<optimized out>, argv=<optimized out>) at git.c:993 #16 0x0000555555573ac8 in main (argc=3, argv=0x7fffffffe088) at common-main.c:52 ``` The operations these commands use are guarded by items such as `index_name_pos()` and others. Since the `.gitmodules` file is always at root, we would not need to expand, anyway.
dscho
pushed a commit
that referenced
this pull request
Nov 16, 2021
When I was playing around with trace2 data and creating flamegraphs, I tried a `git fetch` call to see how the `git-remote-https` command would show up. What I didn't expect was an `ensure_full_index()` region! It turns out that `git fetch` and `git pull` need to check the index for a `.gitmodules` file to see if it should recurse into any submodules. Here is the stack trace from a debugger: ``` #0 ensure_full_index (istate=0x555555ac1c80 <the_index>) at sparse-index.c:404 #1 0x000055555571a979 in do_read_index (istate=istate@entry=0x555555ac1c80 <the_index>, path=path@entry=0x555555ad7b90 ".git/index", must_exist=must_exist@entry=0) at read-cache.c:2386 #2 0x000055555571eb7d in do_read_index (must_exist=0, path=0x555555ad7b90 ".git/index", istate=0x555555ac1c80 <the_index>) at hash.h:244 #3 read_index_from (istate=0x555555ac1c80 <the_index>, path=0x555555ad7b90 ".git/index", gitdir=0x555555ad7b30 ".git") at read-cache.c:2426 #4 0x000055555573f4c2 in repo_read_index (repo=repo@entry=0x555555ac1da0 <the_repo>) at repository.c:286 #5 0x00005555556f14d0 in get_oid_with_context_1 (repo=repo@entry=0x555555ac1da0 <the_repo>, name=name@entry=0x55555582c022 ":.gitmodules", flags=flags@entry=0, prefix=prefix@entry=0x0, oid=oid@entry=0x7fffffffdb00, oc=oc@entry=0x7fffffffda70) at object-name.c:1850 #6 0x00005555556f1f53 in get_oid_with_context (oc=0x7fffffffda70, oid=0x7fffffffdb00, flags=0, str=0x55555582c022 ":.gitmodules", repo=0x555555ac1da0 <the_repo>) at object-name.c:1947 #7 repo_get_oid (r=r@entry=0x555555ac1da0 <the_repo>, name=name@entry=0x55555582c022 ":.gitmodules", oid=oid@entry=0x7fffffffdb00) at object-name.c:1603 #8 0x000055555577330f in config_from_gitmodules (fn=fn@entry=0x555555773460 <gitmodules_fetch_config>, repo=0x555555ac1da0 <the_repo>, data=data@entry=0x7fffffffdb60) at submodule-config.c:650 #9 0x000055555577462d in config_from_gitmodules (data=0x7fffffffdb60, repo=<optimized out>, fn=0x555555773460 <gitmodules_fetch_config>) at submodule-config.c:638 #10 fetch_config_from_gitmodules (max_children=<optimized out>, recurse_submodules=<optimized out>) at submodule-config.c:800 #11 0x00005555555b9e41 in cmd_fetch (argc=1, argv=0x7fffffffe090, prefix=0x0) at builtin/fetch.c:1999 #12 0x0000555555573ff6 in run_builtin (argv=<optimized out>, argc=<optimized out>, p=<optimized out>) at git.c:528 #13 handle_builtin (argc=<optimized out>, argv=<optimized out>) at git.c:785 #14 0x000055555557528c in run_argv (argv=0x7fffffffddf0, argcp=0x7fffffffddfc) at git.c:857 #15 cmd_main (argc=<optimized out>, argv=<optimized out>) at git.c:993 #16 0x0000555555573ac8 in main (argc=3, argv=0x7fffffffe088) at common-main.c:52 ``` The operations these commands use are guarded by items such as `index_name_pos()` and others. Since the `.gitmodules` file is always at root, we would not need to expand, anyway.
dscho
pushed a commit
that referenced
this pull request
Jan 15, 2022
When I was playing around with trace2 data and creating flamegraphs, I tried a `git fetch` call to see how the `git-remote-https` command would show up. What I didn't expect was an `ensure_full_index()` region! It turns out that `git fetch` and `git pull` need to check the index for a `.gitmodules` file to see if it should recurse into any submodules. Here is the stack trace from a debugger: ``` #0 ensure_full_index (istate=0x555555ac1c80 <the_index>) at sparse-index.c:404 #1 0x000055555571a979 in do_read_index (istate=istate@entry=0x555555ac1c80 <the_index>, path=path@entry=0x555555ad7b90 ".git/index", must_exist=must_exist@entry=0) at read-cache.c:2386 #2 0x000055555571eb7d in do_read_index (must_exist=0, path=0x555555ad7b90 ".git/index", istate=0x555555ac1c80 <the_index>) at hash.h:244 #3 read_index_from (istate=0x555555ac1c80 <the_index>, path=0x555555ad7b90 ".git/index", gitdir=0x555555ad7b30 ".git") at read-cache.c:2426 #4 0x000055555573f4c2 in repo_read_index (repo=repo@entry=0x555555ac1da0 <the_repo>) at repository.c:286 #5 0x00005555556f14d0 in get_oid_with_context_1 (repo=repo@entry=0x555555ac1da0 <the_repo>, name=name@entry=0x55555582c022 ":.gitmodules", flags=flags@entry=0, prefix=prefix@entry=0x0, oid=oid@entry=0x7fffffffdb00, oc=oc@entry=0x7fffffffda70) at object-name.c:1850 #6 0x00005555556f1f53 in get_oid_with_context (oc=0x7fffffffda70, oid=0x7fffffffdb00, flags=0, str=0x55555582c022 ":.gitmodules", repo=0x555555ac1da0 <the_repo>) at object-name.c:1947 #7 repo_get_oid (r=r@entry=0x555555ac1da0 <the_repo>, name=name@entry=0x55555582c022 ":.gitmodules", oid=oid@entry=0x7fffffffdb00) at object-name.c:1603 #8 0x000055555577330f in config_from_gitmodules (fn=fn@entry=0x555555773460 <gitmodules_fetch_config>, repo=0x555555ac1da0 <the_repo>, data=data@entry=0x7fffffffdb60) at submodule-config.c:650 #9 0x000055555577462d in config_from_gitmodules (data=0x7fffffffdb60, repo=<optimized out>, fn=0x555555773460 <gitmodules_fetch_config>) at submodule-config.c:638 #10 fetch_config_from_gitmodules (max_children=<optimized out>, recurse_submodules=<optimized out>) at submodule-config.c:800 #11 0x00005555555b9e41 in cmd_fetch (argc=1, argv=0x7fffffffe090, prefix=0x0) at builtin/fetch.c:1999 #12 0x0000555555573ff6 in run_builtin (argv=<optimized out>, argc=<optimized out>, p=<optimized out>) at git.c:528 #13 handle_builtin (argc=<optimized out>, argv=<optimized out>) at git.c:785 #14 0x000055555557528c in run_argv (argv=0x7fffffffddf0, argcp=0x7fffffffddfc) at git.c:857 #15 cmd_main (argc=<optimized out>, argv=<optimized out>) at git.c:993 #16 0x0000555555573ac8 in main (argc=3, argv=0x7fffffffe088) at common-main.c:52 ``` The operations these commands use are guarded by items such as `index_name_pos()` and others. Since the `.gitmodules` file is always at root, we would not need to expand, anyway.
dscho
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Jan 15, 2022
When fetching packfiles, we write a bunch of lockfiles for the packfiles
we're writing into the repository. In order to not leave behind any
cruft in case we exit or receive a signal, we register both an exit
handler as well as signal handlers for common signals like SIGINT. These
handlers will then unlink the locks and free the data structure tracking
them. We have observed a deadlock in this logic though:
(gdb) bt
#0 __lll_lock_wait_private () at ../sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:95
#1 0x00007f4932bea2cd in _int_free (av=0x7f4932f2eb20 <main_arena>, p=0x3e3e4200, have_lock=0) at malloc.c:3969
#2 0x00007f4932bee58c in __GI___libc_free (mem=<optimized out>) at malloc.c:2975
#3 0x0000000000662ab1 in string_list_clear ()
#4 0x000000000044f5bc in unlock_pack_on_signal ()
#5 <signal handler called>
#6 _int_free (av=0x7f4932f2eb20 <main_arena>, p=<optimized out>, have_lock=0) at malloc.c:4024
#7 0x00007f4932bee58c in __GI___libc_free (mem=<optimized out>) at malloc.c:2975
#8 0x000000000065afd5 in strbuf_release ()
#9 0x000000000066ddb9 in delete_tempfile ()
#10 0x0000000000610d0b in files_transaction_cleanup.isra ()
#11 0x0000000000611718 in files_transaction_abort ()
#12 0x000000000060d2ef in ref_transaction_abort ()
#13 0x000000000060d441 in ref_transaction_prepare ()
#14 0x000000000060e0b5 in ref_transaction_commit ()
#15 0x00000000004511c2 in fetch_and_consume_refs ()
#16 0x000000000045279a in cmd_fetch ()
#17 0x0000000000407c48 in handle_builtin ()
#18 0x0000000000408df2 in cmd_main ()
#19 0x00000000004078b5 in main ()
The process was killed with a signal, which caused the signal handler to
kick in and try free the data structures after we have unlinked the
locks. It then deadlocks while calling free(3P).
The root cause of this is that it is not allowed to call certain
functions in async-signal handlers, as specified by signal-safety(7).
Next to most I/O functions, this list of disallowed functions also
includes memory-handling functions like malloc(3P) and free(3P) because
they may not be reentrant. As a result, if we execute such functions in
the signal handler, then they may operate on inconistent state and fail
in unexpected ways.
Fix this bug by not calling non-async-signal-safe functions when running
in the signal handler. We're about to re-raise the signal anyway and
will thus exit, so it's not much of a problem to keep the string list of
lockfiles untouched. Note that it's fine though to call unlink(2), so
we'll still clean up the lockfiles correctly.
Signed-off-by: Patrick Steinhardt <[email protected]>
Reviewed-by: brian m. carlson <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
dscho
pushed a commit
that referenced
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Jan 20, 2022
When I was playing around with trace2 data and creating flamegraphs, I tried a `git fetch` call to see how the `git-remote-https` command would show up. What I didn't expect was an `ensure_full_index()` region! It turns out that `git fetch` and `git pull` need to check the index for a `.gitmodules` file to see if it should recurse into any submodules. Here is the stack trace from a debugger: ``` #0 ensure_full_index (istate=0x555555ac1c80 <the_index>) at sparse-index.c:404 #1 0x000055555571a979 in do_read_index (istate=istate@entry=0x555555ac1c80 <the_index>, path=path@entry=0x555555ad7b90 ".git/index", must_exist=must_exist@entry=0) at read-cache.c:2386 #2 0x000055555571eb7d in do_read_index (must_exist=0, path=0x555555ad7b90 ".git/index", istate=0x555555ac1c80 <the_index>) at hash.h:244 #3 read_index_from (istate=0x555555ac1c80 <the_index>, path=0x555555ad7b90 ".git/index", gitdir=0x555555ad7b30 ".git") at read-cache.c:2426 #4 0x000055555573f4c2 in repo_read_index (repo=repo@entry=0x555555ac1da0 <the_repo>) at repository.c:286 #5 0x00005555556f14d0 in get_oid_with_context_1 (repo=repo@entry=0x555555ac1da0 <the_repo>, name=name@entry=0x55555582c022 ":.gitmodules", flags=flags@entry=0, prefix=prefix@entry=0x0, oid=oid@entry=0x7fffffffdb00, oc=oc@entry=0x7fffffffda70) at object-name.c:1850 #6 0x00005555556f1f53 in get_oid_with_context (oc=0x7fffffffda70, oid=0x7fffffffdb00, flags=0, str=0x55555582c022 ":.gitmodules", repo=0x555555ac1da0 <the_repo>) at object-name.c:1947 #7 repo_get_oid (r=r@entry=0x555555ac1da0 <the_repo>, name=name@entry=0x55555582c022 ":.gitmodules", oid=oid@entry=0x7fffffffdb00) at object-name.c:1603 #8 0x000055555577330f in config_from_gitmodules (fn=fn@entry=0x555555773460 <gitmodules_fetch_config>, repo=0x555555ac1da0 <the_repo>, data=data@entry=0x7fffffffdb60) at submodule-config.c:650 #9 0x000055555577462d in config_from_gitmodules (data=0x7fffffffdb60, repo=<optimized out>, fn=0x555555773460 <gitmodules_fetch_config>) at submodule-config.c:638 #10 fetch_config_from_gitmodules (max_children=<optimized out>, recurse_submodules=<optimized out>) at submodule-config.c:800 #11 0x00005555555b9e41 in cmd_fetch (argc=1, argv=0x7fffffffe090, prefix=0x0) at builtin/fetch.c:1999 #12 0x0000555555573ff6 in run_builtin (argv=<optimized out>, argc=<optimized out>, p=<optimized out>) at git.c:528 #13 handle_builtin (argc=<optimized out>, argv=<optimized out>) at git.c:785 #14 0x000055555557528c in run_argv (argv=0x7fffffffddf0, argcp=0x7fffffffddfc) at git.c:857 #15 cmd_main (argc=<optimized out>, argv=<optimized out>) at git.c:993 #16 0x0000555555573ac8 in main (argc=3, argv=0x7fffffffe088) at common-main.c:52 ``` The operations these commands use are guarded by items such as `index_name_pos()` and others. Since the `.gitmodules` file is always at root, we would not need to expand, anyway.
dscho
pushed a commit
that referenced
this pull request
Apr 7, 2022
In the preceding [1] (pack-objects: move revs out of get_object_list(), 2022-03-22) the "repo_init_revisions()" was moved to cmd_pack_objects() so that it unconditionally took place for all invocations of "git pack-objects". We'd thus start leaking memory, which is easily reproduced in e.g. git.git by feeding e83c516 (Initial revision of "git", the information manager from hell, 2005-04-07) to "git pack-objects"; $ echo e83c516 | ./git pack-objects initial [...] ==19130==ERROR: LeakSanitizer: detected memory leaks Direct leak of 7120 byte(s) in 1 object(s) allocated from: #0 0x455308 in __interceptor_malloc (/home/avar/g/git/git+0x455308) #1 0x75b399 in do_xmalloc /home/avar/g/git/wrapper.c:41:8 #2 0x75b356 in xmalloc /home/avar/g/git/wrapper.c:62:9 #3 0x5d7609 in prep_parse_options /home/avar/g/git/diff.c:5647:2 #4 0x5d415a in repo_diff_setup /home/avar/g/git/diff.c:4621:2 #5 0x6dffbb in repo_init_revisions /home/avar/g/git/revision.c:1853:2 #6 0x4f599d in cmd_pack_objects /home/avar/g/git/builtin/pack-objects.c:3980:2 #7 0x4592ca in run_builtin /home/avar/g/git/git.c:465:11 #8 0x457d81 in handle_builtin /home/avar/g/git/git.c:718:3 #9 0x458ca5 in run_argv /home/avar/g/git/git.c:785:4 #10 0x457b40 in cmd_main /home/avar/g/git/git.c:916:19 #11 0x562259 in main /home/avar/g/git/common-main.c:56:11 #12 0x7fce792ac7ec in __libc_start_main csu/../csu/libc-start.c:332:16 #13 0x4300f9 in _start (/home/avar/g/git/git+0x4300f9) SUMMARY: LeakSanitizer: 7120 byte(s) leaked in 1 allocation(s). Aborted Narrowly fixing that commit would have been easy, just add call repo_init_revisions() right before get_object_list(), which is effectively what was done before that commit. But an unstated constraint when setting it up early is that it was needed for the subsequent [2] (pack-objects: parse --filter directly into revs.filter, 2022-03-22), i.e. we might have a --filter command-line option, and need to either have the "struct rev_info" setup when we encounter that option, or later. Let's just change the control flow so that we'll instead set up the "struct rev_info" only when we need it. Doing so leads to a bit more verbosity, but it's a lot clearer what we're doing and why. An earlier version of this commit[3] went behind opt_parse_list_objects_filter()'s back by faking up a "struct option" before calling it. Let's avoid that and instead create a blessed API for this pattern. We could furthermore combine the two get_object_list() invocations here by having repo_init_revisions() invoked on &pfd.revs, but I think clearly separating the two makes the flow clearer. Likewise redundantly but explicitly (i.e. redundant v.s. a "{ 0 }") "0" to "have_revs" early in cmd_pack_objects(). While we're at it add parentheses around the arguments to the OPT_* macros in in list-objects-filter-options.h, as we need to change those lines anyway. It doesn't matter in this case, but is good general practice. 1. https://lore.kernel.org/git/619b757d98465dbc4995bdc11a5282fbfcbd3daa.1647970119.git.gitgitgadget@gmail.com 2. https://lore.kernel.org/git/97de926904988b89b5663bd4c59c011a1723a8f5.1647970119.git.gitgitgadget@gmail.com 3. https://lore.kernel.org/git/[email protected]/ Signed-off-by: Ævar Arnfjörð Bjarmason <[email protected]> Signed-off-by: Junio C Hamano <[email protected]>
dscho
pushed a commit
that referenced
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Aug 29, 2022
Since commit fcc07e9 (is_promisor_object(): free tree buffer after parsing, 2021-04-13), we'll always free the buffers attached to a "struct tree" after searching them for promisor links. But there's an important case where we don't want to do so: if somebody else is already using the tree! This can happen during a "rev-list --missing=allow-promisor" traversal in a partial clone that is missing one or more trees or blobs. The backtrace for the free looks like this: #1 free_tree_buffer tree.c:147 #2 add_promisor_object packfile.c:2250 #3 for_each_object_in_pack packfile.c:2190 #4 for_each_packed_object packfile.c:2215 #5 is_promisor_object packfile.c:2272 #6 finish_object__ma builtin/rev-list.c:245 #7 finish_object builtin/rev-list.c:261 #8 show_object builtin/rev-list.c:274 #9 process_blob list-objects.c:63 #10 process_tree_contents list-objects.c:145 #11 process_tree list-objects.c:201 #12 traverse_trees_and_blobs list-objects.c:344 [...] We're in the middle of walking through the entries of a tree object via process_tree_contents(). We see a blob (or it could even be another tree entry) that we don't have, so we call is_promisor_object() to check it. That function loops over all of the objects in the promisor packfile, including the tree we're currently walking. When we're done with it there, we free the tree buffer. But as we return to the walk in process_tree_contents(), it's still holding on to a pointer to that buffer, via its tree_desc iterator, and it accesses the freed memory. Even a trivial use of "--missing=allow-promisor" triggers this problem, as the included test demonstrates (it's just a vanilla --blob:none clone). We can detect this case by only freeing the tree buffer if it was allocated on our behalf. This is a little tricky since that happens inside parse_object(), and it doesn't tell us whether the object was already parsed, or whether it allocated the buffer itself. But by checking for an already-parsed tree beforehand, we can distinguish the two cases. That feels a little hacky, and does incur an extra lookup in the object-hash table. But that cost is fairly minimal compared to actually loading objects (and since we're iterating the whole pack here, we're likely to be loading most objects, rather than reusing cached results). It may also be a good direction for this function in general, as there are other possible optimizations that rely on doing some analysis before parsing: - we could detect blobs and avoid reading their contents; they can't link to other objects, but parse_object() doesn't know that we don't care about checking their hashes. - we could avoid allocating object structs entirely for most objects (since we really only need them in the oidset), which would save some memory. - promisor commits could use the commit-graph rather than loading the object from disk This commit doesn't do any of those optimizations, but I think it argues that this direction is reasonable, rather than relying on parse_object() and trying to teach it to give us more information about whether it parsed. The included test fails reliably under SANITIZE=address just when running "rev-list --missing=allow-promisor". Checking the output isn't strictly necessary to detect the bug, but it seems like a reasonable addition given the general lack of coverage for "allow-promisor" in the test suite. Reported-by: Andrew Olsen <[email protected]> Signed-off-by: Jeff King <[email protected]> Signed-off-by: Junio C Hamano <[email protected]>
dscho
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Sep 6, 2022
Fix a memory leak occuring in case of pathspec copy in preload_index.
Direct leak of 8 byte(s) in 8 object(s) allocated from:
#0 0x7f0a353ead47 in __interceptor_malloc (/usr/lib/gcc/x86_64-pc-linux-gnu/11.3.0/libasan.so.6+0xb5d47)
#1 0x55750995e840 in do_xmalloc /home/anthony/src/c/git/wrapper.c:51
#2 0x55750995e840 in xmalloc /home/anthony/src/c/git/wrapper.c:72
#3 0x55750970f824 in copy_pathspec /home/anthony/src/c/git/pathspec.c:684
#4 0x557509717278 in preload_index /home/anthony/src/c/git/preload-index.c:135
#5 0x55750975f21e in refresh_index /home/anthony/src/c/git/read-cache.c:1633
#6 0x55750915b926 in cmd_status builtin/commit.c:1547
#7 0x5575090e1680 in run_builtin /home/anthony/src/c/git/git.c:466
#8 0x5575090e1680 in handle_builtin /home/anthony/src/c/git/git.c:720
#9 0x5575090e284a in run_argv /home/anthony/src/c/git/git.c:787
#10 0x5575090e284a in cmd_main /home/anthony/src/c/git/git.c:920
#11 0x5575090dbf82 in main /home/anthony/src/c/git/common-main.c:56
#12 0x7f0a348230ab (/lib64/libc.so.6+0x290ab)
Signed-off-by: Anthony Delannoy <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
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Jan 23, 2023
There is an out-of-bounds read possible when parsing gitattributes that
have an attribute that is 2^31+1 bytes long. This is caused due to an
integer overflow when we assign the result of strlen(3P) to an `int`,
where we use the wrapped-around value in a subsequent call to
memcpy(3P). The following code reproduces the issue:
blob=$(perl -e 'print "a" x 2147483649 . " attr"' | git hash-object -w --stdin)
git update-index --add --cacheinfo 100644,$blob,.gitattributes
git check-attr --all file
AddressSanitizer:DEADLYSIGNAL
=================================================================
==8451==ERROR: AddressSanitizer: SEGV on unknown address 0x7f93efa00800 (pc 0x7f94f1f8f082 bp 0x7ffddb59b3a0 sp 0x7ffddb59ab28 T0)
==8451==The signal is caused by a READ memory access.
#0 0x7f94f1f8f082 (/usr/lib/libc.so.6+0x176082)
#1 0x7f94f2047d9c in __interceptor_strspn /usr/src/debug/gcc/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:752
#2 0x560e190f7f26 in parse_attr_line attr.c:375
#3 0x560e190f9663 in handle_attr_line attr.c:660
#4 0x560e190f9ddd in read_attr_from_index attr.c:769
#5 0x560e190f9f14 in read_attr attr.c:797
#6 0x560e190fa24e in bootstrap_attr_stack attr.c:867
#7 0x560e190fa4a5 in prepare_attr_stack attr.c:902
#8 0x560e190fb5dc in collect_some_attrs attr.c:1097
#9 0x560e190fb93f in git_all_attrs attr.c:1128
#10 0x560e18e6136e in check_attr builtin/check-attr.c:67
#11 0x560e18e61c12 in cmd_check_attr builtin/check-attr.c:183
#12 0x560e18e15993 in run_builtin git.c:466
#13 0x560e18e16397 in handle_builtin git.c:721
#14 0x560e18e16b2b in run_argv git.c:788
#15 0x560e18e17991 in cmd_main git.c:926
#16 0x560e190ae2bd in main common-main.c:57
#17 0x7f94f1e3c28f (/usr/lib/libc.so.6+0x2328f)
#18 0x7f94f1e3c349 in __libc_start_main (/usr/lib/libc.so.6+0x23349)
#19 0x560e18e110e4 in _start ../sysdeps/x86_64/start.S:115
AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV (/usr/lib/libc.so.6+0x176082)
==8451==ABORTING
Fix this bug by converting the variable to a `size_t` instead.
Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
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Jan 23, 2023
It is possible to trigger an integer overflow when parsing attribute
names when there are more than 2^31 of them for a single pattern. This
can either lead to us dying due to trying to request too many bytes:
blob=$(perl -e 'print "f" . " a=" x 2147483649' | git hash-object -w --stdin)
git update-index --add --cacheinfo 100644,$blob,.gitattributes
git attr-check --all file
=================================================================
==1022==ERROR: AddressSanitizer: requested allocation size 0xfffffff800000032 (0xfffffff800001038 after adjustments for alignment, red zones etc.) exceeds maximum supported size of 0x10000000000 (thread T0)
#0 0x7fd3efabf411 in __interceptor_calloc /usr/src/debug/gcc/libsanitizer/asan/asan_malloc_linux.cpp:77
#1 0x5563a0a1e3d3 in xcalloc wrapper.c:150
#2 0x5563a058d005 in parse_attr_line attr.c:384
#3 0x5563a058e661 in handle_attr_line attr.c:660
#4 0x5563a058eddb in read_attr_from_index attr.c:769
#5 0x5563a058ef12 in read_attr attr.c:797
#6 0x5563a058f24c in bootstrap_attr_stack attr.c:867
#7 0x5563a058f4a3 in prepare_attr_stack attr.c:902
#8 0x5563a05905da in collect_some_attrs attr.c:1097
#9 0x5563a059093d in git_all_attrs attr.c:1128
#10 0x5563a02f636e in check_attr builtin/check-attr.c:67
#11 0x5563a02f6c12 in cmd_check_attr builtin/check-attr.c:183
#12 0x5563a02aa993 in run_builtin git.c:466
#13 0x5563a02ab397 in handle_builtin git.c:721
#14 0x5563a02abb2b in run_argv git.c:788
#15 0x5563a02ac991 in cmd_main git.c:926
#16 0x5563a05432bd in main common-main.c:57
#17 0x7fd3ef82228f (/usr/lib/libc.so.6+0x2328f)
==1022==HINT: if you don't care about these errors you may set allocator_may_return_null=1
SUMMARY: AddressSanitizer: allocation-size-too-big /usr/src/debug/gcc/libsanitizer/asan/asan_malloc_linux.cpp:77 in __interceptor_calloc
==1022==ABORTING
Or, much worse, it can lead to an out-of-bounds write because we
underallocate and then memcpy(3P) into an array:
perl -e '
print "A " . "\rh="x2000000000;
print "\rh="x2000000000;
print "\rh="x294967294 . "\n"
' >.gitattributes
git add .gitattributes
git commit -am "evil attributes"
$ git clone --quiet /path/to/repo
=================================================================
==15062==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x602000002550 at pc 0x5555559884d5 bp 0x7fffffffbc60 sp 0x7fffffffbc58
WRITE of size 8 at 0x602000002550 thread T0
#0 0x5555559884d4 in parse_attr_line attr.c:393
#1 0x5555559884d4 in handle_attr_line attr.c:660
#2 0x555555988902 in read_attr_from_index attr.c:784
#3 0x555555988902 in read_attr_from_index attr.c:747
#4 0x555555988a1d in read_attr attr.c:800
#5 0x555555989b0c in bootstrap_attr_stack attr.c:882
#6 0x555555989b0c in prepare_attr_stack attr.c:917
#7 0x555555989b0c in collect_some_attrs attr.c:1112
#8 0x55555598b141 in git_check_attr attr.c:1126
#9 0x555555a13004 in convert_attrs convert.c:1311
#10 0x555555a95e04 in checkout_entry_ca entry.c:553
#11 0x555555d58bf6 in checkout_entry entry.h:42
#12 0x555555d58bf6 in check_updates unpack-trees.c:480
#13 0x555555d5eb55 in unpack_trees unpack-trees.c:2040
#14 0x555555785ab7 in checkout builtin/clone.c:724
#15 0x555555785ab7 in cmd_clone builtin/clone.c:1384
#16 0x55555572443c in run_builtin git.c:466
#17 0x55555572443c in handle_builtin git.c:721
#18 0x555555727872 in run_argv git.c:788
#19 0x555555727872 in cmd_main git.c:926
#20 0x555555721fa0 in main common-main.c:57
#21 0x7ffff73f1d09 in __libc_start_main ../csu/libc-start.c:308
#22 0x555555723f39 in _start (git+0x1cff39)
0x602000002552 is located 0 bytes to the right of 2-byte region [0x602000002550,0x602000002552) allocated by thread T0 here:
#0 0x7ffff768c037 in __interceptor_calloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:154
#1 0x555555d7fff7 in xcalloc wrapper.c:150
#2 0x55555598815f in parse_attr_line attr.c:384
#3 0x55555598815f in handle_attr_line attr.c:660
#4 0x555555988902 in read_attr_from_index attr.c:784
#5 0x555555988902 in read_attr_from_index attr.c:747
#6 0x555555988a1d in read_attr attr.c:800
#7 0x555555989b0c in bootstrap_attr_stack attr.c:882
#8 0x555555989b0c in prepare_attr_stack attr.c:917
#9 0x555555989b0c in collect_some_attrs attr.c:1112
#10 0x55555598b141 in git_check_attr attr.c:1126
#11 0x555555a13004 in convert_attrs convert.c:1311
#12 0x555555a95e04 in checkout_entry_ca entry.c:553
#13 0x555555d58bf6 in checkout_entry entry.h:42
#14 0x555555d58bf6 in check_updates unpack-trees.c:480
#15 0x555555d5eb55 in unpack_trees unpack-trees.c:2040
#16 0x555555785ab7 in checkout builtin/clone.c:724
#17 0x555555785ab7 in cmd_clone builtin/clone.c:1384
#18 0x55555572443c in run_builtin git.c:466
#19 0x55555572443c in handle_builtin git.c:721
#20 0x555555727872 in run_argv git.c:788
#21 0x555555727872 in cmd_main git.c:926
#22 0x555555721fa0 in main common-main.c:57
#23 0x7ffff73f1d09 in __libc_start_main ../csu/libc-start.c:308
SUMMARY: AddressSanitizer: heap-buffer-overflow attr.c:393 in parse_attr_line
Shadow bytes around the buggy address:
0x0c047fff8450: fa fa 00 02 fa fa 00 07 fa fa fd fd fa fa 00 00
0x0c047fff8460: fa fa 02 fa fa fa fd fd fa fa 00 06 fa fa 05 fa
0x0c047fff8470: fa fa fd fd fa fa 00 02 fa fa 06 fa fa fa 05 fa
0x0c047fff8480: fa fa 07 fa fa fa fd fd fa fa 00 01 fa fa 00 02
0x0c047fff8490: fa fa 00 03 fa fa 00 fa fa fa 00 01 fa fa 00 03
=>0x0c047fff84a0: fa fa 00 01 fa fa 00 02 fa fa[02]fa fa fa fa fa
0x0c047fff84b0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c047fff84c0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c047fff84d0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c047fff84e0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c047fff84f0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
Shadow byte legend (one shadow byte represents 8 application bytes):
Addressable: 00
Partially addressable: 01 02 03 04 05 06 07
Heap left redzone: fa
Freed heap region: fd
Stack left redzone: f1
Stack mid redzone: f2
Stack right redzone: f3
Stack after return: f5
Stack use after scope: f8
Global redzone: f9
Global init order: f6
Poisoned by user: f7
Container overflow: fc
Array cookie: ac
Intra object redzone: bb
ASan internal: fe
Left alloca redzone: ca
Right alloca redzone: cb
Shadow gap: cc
==15062==ABORTING
Fix this bug by using `size_t` instead to count the number of attributes
so that this value cannot reasonably overflow without running out of
memory before already.
Reported-by: Markus Vervier <[email protected]>
Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
dscho
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Jan 23, 2023
When using a padding specifier in the pretty format passed to git-log(1)
we need to calculate the string length in several places. These string
lengths are stored in `int`s though, which means that these can easily
overflow when the input lengths exceeds 2GB. This can ultimately lead to
an out-of-bounds write when these are used in a call to memcpy(3P):
==8340==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x7f1ec62f97fe at pc 0x7f2127e5f427 bp 0x7ffd3bd63de0 sp 0x7ffd3bd63588
WRITE of size 1 at 0x7f1ec62f97fe thread T0
#0 0x7f2127e5f426 in __interceptor_memcpy /usr/src/debug/gcc/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:827
#1 0x5628e96aa605 in format_and_pad_commit pretty.c:1762
#2 0x5628e96aa7f4 in format_commit_item pretty.c:1801
#3 0x5628e97cdb24 in strbuf_expand strbuf.c:429
#4 0x5628e96ab060 in repo_format_commit_message pretty.c:1869
#5 0x5628e96acd0f in pretty_print_commit pretty.c:2161
#6 0x5628e95a44c8 in show_log log-tree.c:781
#7 0x5628e95a76ba in log_tree_commit log-tree.c:1117
#8 0x5628e922bed5 in cmd_log_walk_no_free builtin/log.c:508
#9 0x5628e922c35b in cmd_log_walk builtin/log.c:549
#10 0x5628e922f1a2 in cmd_log builtin/log.c:883
#11 0x5628e9106993 in run_builtin git.c:466
#12 0x5628e9107397 in handle_builtin git.c:721
#13 0x5628e9107b07 in run_argv git.c:788
#14 0x5628e91088a7 in cmd_main git.c:923
#15 0x5628e939d682 in main common-main.c:57
#16 0x7f2127c3c28f (/usr/lib/libc.so.6+0x2328f)
#17 0x7f2127c3c349 in __libc_start_main (/usr/lib/libc.so.6+0x23349)
#18 0x5628e91020e4 in _start ../sysdeps/x86_64/start.S:115
0x7f1ec62f97fe is located 2 bytes to the left of 4831838265-byte region [0x7f1ec62f9800,0x7f1fe62f9839)
allocated by thread T0 here:
#0 0x7f2127ebe7ea in __interceptor_realloc /usr/src/debug/gcc/libsanitizer/asan/asan_malloc_linux.cpp:85
#1 0x5628e98774d4 in xrealloc wrapper.c:136
#2 0x5628e97cb01c in strbuf_grow strbuf.c:99
#3 0x5628e97ccd42 in strbuf_addchars strbuf.c:327
#4 0x5628e96aa55c in format_and_pad_commit pretty.c:1761
#5 0x5628e96aa7f4 in format_commit_item pretty.c:1801
#6 0x5628e97cdb24 in strbuf_expand strbuf.c:429
#7 0x5628e96ab060 in repo_format_commit_message pretty.c:1869
#8 0x5628e96acd0f in pretty_print_commit pretty.c:2161
#9 0x5628e95a44c8 in show_log log-tree.c:781
#10 0x5628e95a76ba in log_tree_commit log-tree.c:1117
#11 0x5628e922bed5 in cmd_log_walk_no_free builtin/log.c:508
#12 0x5628e922c35b in cmd_log_walk builtin/log.c:549
#13 0x5628e922f1a2 in cmd_log builtin/log.c:883
#14 0x5628e9106993 in run_builtin git.c:466
#15 0x5628e9107397 in handle_builtin git.c:721
#16 0x5628e9107b07 in run_argv git.c:788
#17 0x5628e91088a7 in cmd_main git.c:923
#18 0x5628e939d682 in main common-main.c:57
#19 0x7f2127c3c28f (/usr/lib/libc.so.6+0x2328f)
#20 0x7f2127c3c349 in __libc_start_main (/usr/lib/libc.so.6+0x23349)
#21 0x5628e91020e4 in _start ../sysdeps/x86_64/start.S:115
SUMMARY: AddressSanitizer: heap-buffer-overflow /usr/src/debug/gcc/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:827 in __interceptor_memcpy
Shadow bytes around the buggy address:
0x0fe458c572a0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0fe458c572b0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0fe458c572c0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0fe458c572d0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0fe458c572e0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
=>0x0fe458c572f0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa[fa]
0x0fe458c57300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0fe458c57310: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0fe458c57320: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0fe458c57330: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0fe458c57340: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Shadow byte legend (one shadow byte represents 8 application bytes):
Addressable: 00
Partially addressable: 01 02 03 04 05 06 07
Heap left redzone: fa
Freed heap region: fd
Stack left redzone: f1
Stack mid redzone: f2
Stack right redzone: f3
Stack after return: f5
Stack use after scope: f8
Global redzone: f9
Global init order: f6
Poisoned by user: f7
Container overflow: fc
Array cookie: ac
Intra object redzone: bb
ASan internal: fe
Left alloca redzone: ca
Right alloca redzone: cb
==8340==ABORTING
The pretty format can also be used in `git archive` operations via the
`export-subst` attribute. So this is what in our opinion makes this a
critical issue in the context of Git forges which allow to download an
archive of user supplied Git repositories.
Fix this vulnerability by using `size_t` instead of `int` to track the
string lengths. Add tests which detect this vulnerability when Git is
compiled with the address sanitizer.
Reported-by: Joern Schneeweisz <[email protected]>
Original-patch-by: Joern Schneeweisz <[email protected]>
Modified-by: Taylor Blau <[email protected]>
Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
dscho
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that referenced
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Jan 23, 2023
With the `%>>(<N>)` pretty formatter, you can ask git-log(1) et al to
steal spaces. To do so we need to look ahead of the next token to see
whether there are spaces there. This loop takes into account ANSI
sequences that end with an `m`, and if it finds any it will skip them
until it finds the first space. While doing so it does not take into
account the buffer's limits though and easily does an out-of-bounds
read.
Add a test that hits this behaviour. While we don't have an easy way to
verify this, the test causes the following failure when run with
`SANITIZE=address`:
==37941==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x603000000baf at pc 0x55ba6f88e0d0 bp 0x7ffc84c50d20 sp 0x7ffc84c50d10
READ of size 1 at 0x603000000baf thread T0
#0 0x55ba6f88e0cf in format_and_pad_commit pretty.c:1712
#1 0x55ba6f88e7b4 in format_commit_item pretty.c:1801
#2 0x55ba6f9b1ae4 in strbuf_expand strbuf.c:429
#3 0x55ba6f88f020 in repo_format_commit_message pretty.c:1869
#4 0x55ba6f890ccf in pretty_print_commit pretty.c:2161
#5 0x55ba6f7884c8 in show_log log-tree.c:781
#6 0x55ba6f78b6ba in log_tree_commit log-tree.c:1117
#7 0x55ba6f40fed5 in cmd_log_walk_no_free builtin/log.c:508
#8 0x55ba6f41035b in cmd_log_walk builtin/log.c:549
#9 0x55ba6f4131a2 in cmd_log builtin/log.c:883
#10 0x55ba6f2ea993 in run_builtin git.c:466
#11 0x55ba6f2eb397 in handle_builtin git.c:721
#12 0x55ba6f2ebb07 in run_argv git.c:788
#13 0x55ba6f2ec8a7 in cmd_main git.c:923
#14 0x55ba6f581682 in main common-main.c:57
#15 0x7f2d08c3c28f (/usr/lib/libc.so.6+0x2328f)
#16 0x7f2d08c3c349 in __libc_start_main (/usr/lib/libc.so.6+0x23349)
#17 0x55ba6f2e60e4 in _start ../sysdeps/x86_64/start.S:115
0x603000000baf is located 1 bytes to the left of 24-byte region [0x603000000bb0,0x603000000bc8)
allocated by thread T0 here:
#0 0x7f2d08ebe7ea in __interceptor_realloc /usr/src/debug/gcc/libsanitizer/asan/asan_malloc_linux.cpp:85
#1 0x55ba6fa5b494 in xrealloc wrapper.c:136
#2 0x55ba6f9aefdc in strbuf_grow strbuf.c:99
#3 0x55ba6f9b0a06 in strbuf_add strbuf.c:298
#4 0x55ba6f9b1a25 in strbuf_expand strbuf.c:418
#5 0x55ba6f88f020 in repo_format_commit_message pretty.c:1869
#6 0x55ba6f890ccf in pretty_print_commit pretty.c:2161
#7 0x55ba6f7884c8 in show_log log-tree.c:781
#8 0x55ba6f78b6ba in log_tree_commit log-tree.c:1117
#9 0x55ba6f40fed5 in cmd_log_walk_no_free builtin/log.c:508
#10 0x55ba6f41035b in cmd_log_walk builtin/log.c:549
#11 0x55ba6f4131a2 in cmd_log builtin/log.c:883
#12 0x55ba6f2ea993 in run_builtin git.c:466
#13 0x55ba6f2eb397 in handle_builtin git.c:721
#14 0x55ba6f2ebb07 in run_argv git.c:788
#15 0x55ba6f2ec8a7 in cmd_main git.c:923
#16 0x55ba6f581682 in main common-main.c:57
#17 0x7f2d08c3c28f (/usr/lib/libc.so.6+0x2328f)
#18 0x7f2d08c3c349 in __libc_start_main (/usr/lib/libc.so.6+0x23349)
#19 0x55ba6f2e60e4 in _start ../sysdeps/x86_64/start.S:115
SUMMARY: AddressSanitizer: heap-buffer-overflow pretty.c:1712 in format_and_pad_commit
Shadow bytes around the buggy address:
0x0c067fff8120: fa fa fd fd fd fa fa fa fd fd fd fa fa fa fd fd
0x0c067fff8130: fd fd fa fa fd fd fd fd fa fa fd fd fd fa fa fa
0x0c067fff8140: fd fd fd fa fa fa fd fd fd fa fa fa fd fd fd fa
0x0c067fff8150: fa fa fd fd fd fd fa fa 00 00 00 fa fa fa fd fd
0x0c067fff8160: fd fa fa fa fd fd fd fa fa fa fd fd fd fa fa fa
=>0x0c067fff8170: fd fd fd fa fa[fa]00 00 00 fa fa fa 00 00 00 fa
0x0c067fff8180: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c067fff8190: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c067fff81a0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c067fff81b0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c067fff81c0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
Shadow byte legend (one shadow byte represents 8 application bytes):
Addressable: 00
Partially addressable: 01 02 03 04 05 06 07
Heap left redzone: fa
Freed heap region: fd
Stack left redzone: f1
Stack mid redzone: f2
Stack right redzone: f3
Stack after return: f5
Stack use after scope: f8
Global redzone: f9
Global init order: f6
Poisoned by user: f7
Container overflow: fc
Array cookie: ac
Intra object redzone: bb
ASan internal: fe
Left alloca redzone: ca
Right alloca redzone: cb
Luckily enough, this would only cause us to copy the out-of-bounds data
into the formatted commit in case we really had an ANSI sequence
preceding our buffer. So this bug likely has no security consequences.
Fix it regardless by not traversing past the buffer's start.
Reported-by: Patrick Steinhardt <[email protected]>
Reported-by: Eric Sesterhenn <[email protected]>
Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
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Jan 23, 2023
An out-of-bounds read can be triggered when parsing an incomplete padding format string passed via `--pretty=format` or in Git archives when files are marked with the `export-subst` gitattribute. This bug exists since we have introduced support for truncating output via the `trunc` keyword a7f01c6 (pretty: support truncating in %>, %< and %><, 2013-04-19). Before this commit, we used to find the end of the formatting string by using strchr(3P). This function returns a `NULL` pointer in case the character in question wasn't found. The subsequent check whether any character was found thus simply checked the returned pointer. After the commit we switched to strcspn(3P) though, which only returns the offset to the first found character or to the trailing NUL byte. As the end pointer is now computed by adding the offset to the start pointer it won't be `NULL` anymore, and as a consequence the check doesn't do anything anymore. The out-of-bounds data that is being read can in fact end up in the formatted string. As a consequence, it is possible to leak memory contents either by calling git-log(1) or via git-archive(1) when any of the archived files is marked with the `export-subst` gitattribute. ==10888==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x602000000398 at pc 0x7f0356047cb2 bp 0x7fff3ffb95d0 sp 0x7fff3ffb8d78 READ of size 1 at 0x602000000398 thread T0 #0 0x7f0356047cb1 in __interceptor_strchrnul /usr/src/debug/gcc/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:725 #1 0x563b7cec9a43 in strbuf_expand strbuf.c:417 #2 0x563b7cda7060 in repo_format_commit_message pretty.c:1869 #3 0x563b7cda8d0f in pretty_print_commit pretty.c:2161 #4 0x563b7cca04c8 in show_log log-tree.c:781 #5 0x563b7cca36ba in log_tree_commit log-tree.c:1117 #6 0x563b7c927ed5 in cmd_log_walk_no_free builtin/log.c:508 #7 0x563b7c92835b in cmd_log_walk builtin/log.c:549 #8 0x563b7c92b1a2 in cmd_log builtin/log.c:883 #9 0x563b7c802993 in run_builtin git.c:466 #10 0x563b7c803397 in handle_builtin git.c:721 #11 0x563b7c803b07 in run_argv git.c:788 #12 0x563b7c8048a7 in cmd_main git.c:923 #13 0x563b7ca99682 in main common-main.c:57 #14 0x7f0355e3c28f (/usr/lib/libc.so.6+0x2328f) #15 0x7f0355e3c349 in __libc_start_main (/usr/lib/libc.so.6+0x23349) #16 0x563b7c7fe0e4 in _start ../sysdeps/x86_64/start.S:115 0x602000000398 is located 0 bytes to the right of 8-byte region [0x602000000390,0x602000000398) allocated by thread T0 here: #0 0x7f0356072faa in __interceptor_strdup /usr/src/debug/gcc/libsanitizer/asan/asan_interceptors.cpp:439 #1 0x563b7cf7317c in xstrdup wrapper.c:39 #2 0x563b7cd9a06a in save_user_format pretty.c:40 #3 0x563b7cd9b3e5 in get_commit_format pretty.c:173 #4 0x563b7ce54ea0 in handle_revision_opt revision.c:2456 #5 0x563b7ce597c9 in setup_revisions revision.c:2850 #6 0x563b7c9269e0 in cmd_log_init_finish builtin/log.c:269 #7 0x563b7c927362 in cmd_log_init builtin/log.c:348 #8 0x563b7c92b193 in cmd_log builtin/log.c:882 #9 0x563b7c802993 in run_builtin git.c:466 #10 0x563b7c803397 in handle_builtin git.c:721 #11 0x563b7c803b07 in run_argv git.c:788 #12 0x563b7c8048a7 in cmd_main git.c:923 #13 0x563b7ca99682 in main common-main.c:57 #14 0x7f0355e3c28f (/usr/lib/libc.so.6+0x2328f) #15 0x7f0355e3c349 in __libc_start_main (/usr/lib/libc.so.6+0x23349) #16 0x563b7c7fe0e4 in _start ../sysdeps/x86_64/start.S:115 SUMMARY: AddressSanitizer: heap-buffer-overflow /usr/src/debug/gcc/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:725 in __interceptor_strchrnul Shadow bytes around the buggy address: 0x0c047fff8020: fa fa fd fd fa fa 00 06 fa fa 05 fa fa fa fd fd 0x0c047fff8030: fa fa 00 02 fa fa 06 fa fa fa 05 fa fa fa fd fd 0x0c047fff8040: fa fa 00 07 fa fa 03 fa fa fa fd fd fa fa 00 00 0x0c047fff8050: fa fa 00 01 fa fa fd fd fa fa 00 00 fa fa 00 01 0x0c047fff8060: fa fa 00 06 fa fa 00 06 fa fa 05 fa fa fa 05 fa =>0x0c047fff8070: fa fa 00[fa]fa fa fd fa fa fa fd fd fa fa fd fd 0x0c047fff8080: fa fa fd fd fa fa 00 00 fa fa 00 fa fa fa fd fa 0x0c047fff8090: fa fa fd fd fa fa 00 00 fa fa fa fa fa fa fa fa 0x0c047fff80a0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c047fff80b0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c047fff80c0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa Shadow byte legend (one shadow byte represents 8 application bytes): Addressable: 00 Partially addressable: 01 02 03 04 05 06 07 Heap left redzone: fa Freed heap region: fd Stack left redzone: f1 Stack mid redzone: f2 Stack right redzone: f3 Stack after return: f5 Stack use after scope: f8 Global redzone: f9 Global init order: f6 Poisoned by user: f7 Container overflow: fc Array cookie: ac Intra object redzone: bb ASan internal: fe Left alloca redzone: ca Right alloca redzone: cb ==10888==ABORTING Fix this bug by checking whether `end` points at the trailing NUL byte. Add a test which catches this out-of-bounds read and which demonstrates that we used to write out-of-bounds data into the formatted message. Reported-by: Markus Vervier <[email protected]> Original-patch-by: Markus Vervier <[email protected]> Signed-off-by: Patrick Steinhardt <[email protected]> Signed-off-by: Junio C Hamano <[email protected]>
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The return type of both `utf8_strwidth()` and `utf8_strnwidth()` is
`int`, but we operate on string lengths which are typically of type
`size_t`. This means that when the string is longer than `INT_MAX`, we
will overflow and thus return a negative result.
This can lead to an out-of-bounds write with `--pretty=format:%<1)%B`
and a commit message that is 2^31+1 bytes long:
=================================================================
==26009==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x603000001168 at pc 0x7f95c4e5f427 bp 0x7ffd8541c900 sp 0x7ffd8541c0a8
WRITE of size 2147483649 at 0x603000001168 thread T0
#0 0x7f95c4e5f426 in __interceptor_memcpy /usr/src/debug/gcc/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:827
#1 0x5612bbb1068c in format_and_pad_commit pretty.c:1763
#2 0x5612bbb1087a in format_commit_item pretty.c:1801
#3 0x5612bbc33bab in strbuf_expand strbuf.c:429
#4 0x5612bbb110e7 in repo_format_commit_message pretty.c:1869
#5 0x5612bbb12d96 in pretty_print_commit pretty.c:2161
#6 0x5612bba0a4d5 in show_log log-tree.c:781
#7 0x5612bba0d6c7 in log_tree_commit log-tree.c:1117
#8 0x5612bb691ed5 in cmd_log_walk_no_free builtin/log.c:508
#9 0x5612bb69235b in cmd_log_walk builtin/log.c:549
#10 0x5612bb6951a2 in cmd_log builtin/log.c:883
#11 0x5612bb56c993 in run_builtin git.c:466
#12 0x5612bb56d397 in handle_builtin git.c:721
#13 0x5612bb56db07 in run_argv git.c:788
#14 0x5612bb56e8a7 in cmd_main git.c:923
#15 0x5612bb803682 in main common-main.c:57
#16 0x7f95c4c3c28f (/usr/lib/libc.so.6+0x2328f)
#17 0x7f95c4c3c349 in __libc_start_main (/usr/lib/libc.so.6+0x23349)
#18 0x5612bb5680e4 in _start ../sysdeps/x86_64/start.S:115
0x603000001168 is located 0 bytes to the right of 24-byte region [0x603000001150,0x603000001168)
allocated by thread T0 here:
#0 0x7f95c4ebe7ea in __interceptor_realloc /usr/src/debug/gcc/libsanitizer/asan/asan_malloc_linux.cpp:85
#1 0x5612bbcdd556 in xrealloc wrapper.c:136
#2 0x5612bbc310a3 in strbuf_grow strbuf.c:99
#3 0x5612bbc32acd in strbuf_add strbuf.c:298
#4 0x5612bbc33aec in strbuf_expand strbuf.c:418
#5 0x5612bbb110e7 in repo_format_commit_message pretty.c:1869
#6 0x5612bbb12d96 in pretty_print_commit pretty.c:2161
#7 0x5612bba0a4d5 in show_log log-tree.c:781
#8 0x5612bba0d6c7 in log_tree_commit log-tree.c:1117
#9 0x5612bb691ed5 in cmd_log_walk_no_free builtin/log.c:508
#10 0x5612bb69235b in cmd_log_walk builtin/log.c:549
#11 0x5612bb6951a2 in cmd_log builtin/log.c:883
#12 0x5612bb56c993 in run_builtin git.c:466
#13 0x5612bb56d397 in handle_builtin git.c:721
#14 0x5612bb56db07 in run_argv git.c:788
#15 0x5612bb56e8a7 in cmd_main git.c:923
#16 0x5612bb803682 in main common-main.c:57
#17 0x7f95c4c3c28f (/usr/lib/libc.so.6+0x2328f)
SUMMARY: AddressSanitizer: heap-buffer-overflow /usr/src/debug/gcc/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:827 in __interceptor_memcpy
Shadow bytes around the buggy address:
0x0c067fff81d0: fd fd fd fa fa fa fd fd fd fa fa fa fd fd fd fa
0x0c067fff81e0: fa fa fd fd fd fd fa fa fd fd fd fd fa fa fd fd
0x0c067fff81f0: fd fa fa fa fd fd fd fa fa fa fd fd fd fa fa fa
0x0c067fff8200: fd fd fd fa fa fa fd fd fd fd fa fa 00 00 00 fa
0x0c067fff8210: fa fa fd fd fd fa fa fa fd fd fd fa fa fa fd fd
=>0x0c067fff8220: fd fa fa fa fd fd fd fa fa fa 00 00 00[fa]fa fa
0x0c067fff8230: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c067fff8240: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c067fff8250: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c067fff8260: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c067fff8270: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
Shadow byte legend (one shadow byte represents 8 application bytes):
Addressable: 00
Partially addressable: 01 02 03 04 05 06 07
Heap left redzone: fa
Freed heap region: fd
Stack left redzone: f1
Stack mid redzone: f2
Stack right redzone: f3
Stack after return: f5
Stack use after scope: f8
Global redzone: f9
Global init order: f6
Poisoned by user: f7
Container overflow: fc
Array cookie: ac
Intra object redzone: bb
ASan internal: fe
Left alloca redzone: ca
Right alloca redzone: cb
==26009==ABORTING
Now the proper fix for this would be to convert both functions to return
an `size_t` instead of an `int`. But given that this commit may be part
of a security release, let's instead do the minimal viable fix and die
in case we see an overflow.
Add a test that would have previously caused us to crash.
Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
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When "read_strategy_opts()" is called we may have populated the
"opts->strategy" before, so we'll need to free() it to avoid leaking
memory.
We populate it before because we cal get_replay_opts() from within
"rebase.c" with an already populated "opts", which we then copy. Then
if we're doing a "rebase -i" the sequencer API itself will promptly
clobber our alloc'd version of it with its own.
If this code is changed to do, instead of the added free() here a:
if (opts->strategy)
opts->strategy = xstrdup("another leak");
We get a couple of stacktraces from -fsanitize=leak showing how we
ended up clobbering the already allocated value, i.e.:
Direct leak of 6 byte(s) in 1 object(s) allocated from:
#0 0x7f2e8cd45545 in __interceptor_malloc ../../../../src/libsanitizer/lsan/lsan_interceptors.cpp:75
#1 0x7f2e8cb0fcaa in __GI___strdup string/strdup.c:42
#2 0x6c4778 in xstrdup wrapper.c:39
#3 0x66bcb8 in read_strategy_opts sequencer.c:2902
#4 0x66bf7b in read_populate_opts sequencer.c:2969
#5 0x6723f9 in sequencer_continue sequencer.c:5063
#6 0x4a4f74 in run_sequencer_rebase builtin/rebase.c:348
#7 0x4a64c8 in run_specific_rebase builtin/rebase.c:753
#8 0x4a9b8b in cmd_rebase builtin/rebase.c:1824
#9 0x407a32 in run_builtin git.c:466
#10 0x407e0a in handle_builtin git.c:721
#11 0x40803d in run_argv git.c:788
#12 0x40850f in cmd_main git.c:923
#13 0x4eee79 in main common-main.c:57
#14 0x7f2e8ca9f209 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
#15 0x7f2e8ca9f2bb in __libc_start_main_impl ../csu/libc-start.c:389
#16 0x405fd0 in _start (git+0x405fd0)
Direct leak of 4 byte(s) in 1 object(s) allocated from:
#0 0x7f2e8cd45545 in __interceptor_malloc ../../../../src/libsanitizer/lsan/lsan_interceptors.cpp:75
#1 0x7f2e8cb0fcaa in __GI___strdup string/strdup.c:42
#2 0x6c4778 in xstrdup wrapper.c:39
#3 0x4a3c31 in xstrdup_or_null git-compat-util.h:1169
#4 0x4a447a in get_replay_opts builtin/rebase.c:163
#5 0x4a4f5b in run_sequencer_rebase builtin/rebase.c:346
#6 0x4a64c8 in run_specific_rebase builtin/rebase.c:753
#7 0x4a9b8b in cmd_rebase builtin/rebase.c:1824
#8 0x407a32 in run_builtin git.c:466
#9 0x407e0a in handle_builtin git.c:721
#10 0x40803d in run_argv git.c:788
#11 0x40850f in cmd_main git.c:923
#12 0x4eee79 in main common-main.c:57
#13 0x7f2e8ca9f209 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
#14 0x7f2e8ca9f2bb in __libc_start_main_impl ../csu/libc-start.c:389
#15 0x405fd0 in _start (git+0x405fd0)
This can be seen in e.g. the 4th test of
"t3404-rebase-interactive.sh".
In the larger picture the ownership of the "struct replay_opts" is
quite a mess, e.g. in this case rebase.c's static "get_replay_opts()"
function partially creates it, but nothing in rebase.c will free()
it. The structure is "mostly owned" by the sequencer API, but it also
expects to get these partially populated versions of it.
It would be better to have rebase keep track of what it allocated, and
free() that, and to pass that as a "const" to the sequencer API, which
would copy what it needs to its own version, and to free() that.
But doing so is a much larger change, and however messy the ownership
boundary is here is consistent with what we're doing already, so let's
just free() this to fix the leak.
Signed-off-by: Ævar Arnfjörð Bjarmason <[email protected]>
Signed-off-by: Taylor Blau <[email protected]>
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When t5583-push-branches.sh was originally introduced via 425b4d7 (push: introduce '--branches' option, 2023-05-06), it was not leak-free. In fact, the test did not even run correctly until 022fbb6 (t5583: fix shebang line, 2023-05-12), but after applying that patch, we see a failure at t5583.8: ==2529087==ERROR: LeakSanitizer: detected memory leaks Direct leak of 384 byte(s) in 1 object(s) allocated from: #0 0x7fb536330986 in __interceptor_realloc ../../../../src/libsanitizer/lsan/lsan_interceptors.cpp:98 #1 0x55e07606cbf9 in xrealloc wrapper.c:140 #2 0x55e075fb6cb3 in prio_queue_put prio-queue.c:42 #3 0x55e075ec81cb in get_reachable_subset commit-reach.c:917 #4 0x55e075fe9cce in add_missing_tags remote.c:1518 #5 0x55e075fea1e4 in match_push_refs remote.c:1665 #6 0x55e076050a8e in transport_push transport.c:1378 #7 0x55e075e2eb74 in push_with_options builtin/push.c:401 #8 0x55e075e2edb0 in do_push builtin/push.c:458 #9 0x55e075e2ff7a in cmd_push builtin/push.c:702 #10 0x55e075d8aaf0 in run_builtin git.c:452 #11 0x55e075d8af08 in handle_builtin git.c:706 #12 0x55e075d8b12c in run_argv git.c:770 #13 0x55e075d8b6a0 in cmd_main git.c:905 #14 0x55e075e81f07 in main common-main.c:60 #15 0x7fb5360ab6c9 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58 #16 0x7fb5360ab784 in __libc_start_main_impl ../csu/libc-start.c:360 #17 0x55e075d88f40 in _start (git+0x1ff40) (BuildId: 38ad998b85a535e786129979443630d025ec2453) SUMMARY: LeakSanitizer: 384 byte(s) leaked in 1 allocation(s). This leak was addressed independently via 68b5117 (commit-reach: fix memory leak in get_reachable_subset(), 2023-06-03), which makes t5583 leak-free. But t5583 was not in the tree when 68b5117 was written, and the two only met after the latter was merged back in via 693bde4 (Merge branch 'mh/commit-reach-get-reachable-plug-leak', 2023-06-20). At that point, t5583 was leak-free. Let's mark it as such accordingly. Signed-off-by: Taylor Blau <[email protected]> Acked-by: Jeff King <[email protected]> Signed-off-by: Junio C Hamano <[email protected]>
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Memory sanitizer (msan) is detecting a use of an uninitialized variable
(`size`) in `read_attr_from_index`:
==2268==WARNING: MemorySanitizer: use-of-uninitialized-value
#0 0x5651f3416504 in read_attr_from_index git/attr.c:868:11
#1 0x5651f3415530 in read_attr git/attr.c
#2 0x5651f3413d74 in bootstrap_attr_stack git/attr.c:968:6
#3 0x5651f3413d74 in prepare_attr_stack git/attr.c:1004:2
#4 0x5651f3413d74 in collect_some_attrs git/attr.c:1199:2
#5 0x5651f3413144 in git_check_attr git/attr.c:1345:2
#6 0x5651f34728da in convert_attrs git/convert.c:1320:2
#7 0x5651f3473425 in would_convert_to_git_filter_fd git/convert.c:1373:2
#8 0x5651f357a35e in index_fd git/object-file.c:2630:34
#9 0x5651f357aa15 in index_path git/object-file.c:2657:7
#10 0x5651f35db9d9 in add_to_index git/read-cache.c:766:7
#11 0x5651f35dc170 in add_file_to_index git/read-cache.c:799:9
#12 0x5651f321f9b2 in add_files git/builtin/add.c:346:7
#13 0x5651f321f9b2 in cmd_add git/builtin/add.c:565:18
#14 0x5651f321d327 in run_builtin git/git.c:474:11
#15 0x5651f321bc9e in handle_builtin git/git.c:729:3
#16 0x5651f321a792 in run_argv git/git.c:793:4
#17 0x5651f321a792 in cmd_main git/git.c:928:19
#18 0x5651f33dde1f in main git/common-main.c:62:11
The issue exists because `size` is an output parameter from
`read_blob_data_from_index`, but it's only modified if
`read_blob_data_from_index` returns non-NULL. The read of `size` when
calling `read_attr_from_buf` unconditionally may read from an
uninitialized value. `read_attr_from_buf` checks that `buf` is non-NULL
before reading from `size`, but by then it's already too late: the
uninitialized read will have happened already. Furthermore, there's no
guarantee that the compiler won't reorder things so that it checks
`size` before checking `!buf`.
Make the call to `read_attr_from_buf` conditional on `buf` being
non-NULL, ensuring that `size` is not read if it's never set.
Signed-off-by: Kyle Lippincott <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
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It was recently reported that concurrent reads and writes may cause the
reftable backend to segfault. The root cause of this is that we do not
properly keep track of reftable readers across reloads.
Suppose that you have a reftable iterator and then decide to reload the
stack while iterating through the iterator. When the stack has been
rewritten since we have created the iterator, then we would end up
discarding a subset of readers that may still be in use by the iterator.
The consequence is that we now try to reference deallocated memory,
which of course segfaults.
One way to trigger this is in t5616, where some background maintenance
jobs have been leaking from one test into another. This leads to stack
traces like the following one:
+ git -c protocol.version=0 -C pc1 fetch --filter=blob:limit=29999 --refetch origin
AddressSanitizer:DEADLYSIGNAL
=================================================================
==657994==ERROR: AddressSanitizer: SEGV on unknown address 0x7fa0f0ec6089 (pc 0x55f23e52ddf9 bp
0x7ffe7bfa1700 sp 0x7ffe7bfa1700 T0)
==657994==The signal is caused by a READ memory access.
#0 0x55f23e52ddf9 in get_var_int reftable/record.c:29
#1 0x55f23e53295e in reftable_decode_keylen reftable/record.c:170
#2 0x55f23e532cc0 in reftable_decode_key reftable/record.c:194
#3 0x55f23e54e72e in block_iter_next reftable/block.c:398
#4 0x55f23e5573dc in table_iter_next_in_block reftable/reader.c:240
#5 0x55f23e5573dc in table_iter_next reftable/reader.c:355
#6 0x55f23e5573dc in table_iter_next reftable/reader.c:339
#7 0x55f23e551283 in merged_iter_advance_subiter reftable/merged.c:69
#8 0x55f23e55169e in merged_iter_next_entry reftable/merged.c:123
#9 0x55f23e55169e in merged_iter_next_void reftable/merged.c:172
#10 0x55f23e537625 in reftable_iterator_next_ref reftable/generic.c:175
#11 0x55f23e2cf9c6 in reftable_ref_iterator_advance refs/reftable-backend.c:464
#12 0x55f23e2d996e in ref_iterator_advance refs/iterator.c:13
#13 0x55f23e2d996e in do_for_each_ref_iterator refs/iterator.c:452
#14 0x55f23dca6767 in get_ref_map builtin/fetch.c:623
#15 0x55f23dca6767 in do_fetch builtin/fetch.c:1659
#16 0x55f23dca6767 in fetch_one builtin/fetch.c:2133
#17 0x55f23dca6767 in cmd_fetch builtin/fetch.c:2432
#18 0x55f23dba7764 in run_builtin git.c:484
#19 0x55f23dba7764 in handle_builtin git.c:741
#20 0x55f23dbab61e in run_argv git.c:805
#21 0x55f23dbab61e in cmd_main git.c:1000
#22 0x55f23dba4781 in main common-main.c:64
#23 0x7fa0f063fc89 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
#24 0x7fa0f063fd44 in __libc_start_main_impl ../csu/libc-start.c:360
#25 0x55f23dba6ad0 in _start (git+0xadfad0) (BuildId: 803b2b7f59beb03d7849fb8294a8e2145dd4aa27)
While it is somewhat awkward that the maintenance processes survive
tests in the first place, it is totally expected that reftables should
work alright with concurrent writers. Seemingly they don't.
The only underlying resource that we need to care about in this context
is the reftable reader, which is responsible for reading a single table
from disk. These readers get discarded immediately (unless reused) when
calling `reftable_stack_reload()`, which is wrong. We can only close
them once we know that there are no iterators using them anymore.
Prepare for a fix by converting the reftable readers to be refcounted.
Reported-by: Jeff King <[email protected]>
Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
dscho
added a commit
that referenced
this pull request
Oct 21, 2024
An internal customer reported a segfault when running `git sparse-checkout set` with the `index.sparse` config enabled. I was unable to reproduce it locally, but with their help we debugged into the failing process and discovered the following stacktrace: ``` #0 0x00007ff6318fb7b0 in rehash (map=0x3dfb00d0440, newsize=1048576) at hashmap.c:125 #1 0x00007ff6318fbc66 in hashmap_add (map=0x3dfb00d0440, entry=0x3dfb5c58bc8) at hashmap.c:247 #2 0x00007ff631937a70 in hash_index_entry (istate=0x3dfb00d0400, ce=0x3dfb5c58bc8) at name-hash.c:122 #3 0x00007ff631938a2f in add_name_hash (istate=0x3dfb00d0400, ce=0x3dfb5c58bc8) at name-hash.c:638 #4 0x00007ff631a064de in set_index_entry (istate=0x3dfb00d0400, nr=8291, ce=0x3dfb5c58bc8) at sparse-index.c:255 #5 0x00007ff631a06692 in add_path_to_index (oid=0x5ff130, base=0x5ff580, path=0x3dfb4b725da "<redacted>", mode=33188, context=0x5ff570) at sparse-index.c:307 #6 0x00007ff631a3b48c in read_tree_at (r=0x7ff631c026a0 <the_repo>, tree=0x3dfb5b41f60, base=0x5ff580, depth=2, pathspec=0x5ff5a0, fn=0x7ff631a064e5 <add_path_to_index>, context=0x5ff570) at tree.c:46 #7 0x00007ff631a3b60b in read_tree_at (r=0x7ff631c026a0 <the_repo>, tree=0x3dfb5b41e80, base=0x5ff580, depth=1, pathspec=0x5ff5a0, fn=0x7ff631a064e5 <add_path_to_index>, context=0x5ff570) at tree.c:80 #8 0x00007ff631a3b60b in read_tree_at (r=0x7ff631c026a0 <the_repo>, tree=0x3dfb5b41ac8, base=0x5ff580, depth=0, pathspec=0x5ff5a0, fn=0x7ff631a064e5 <add_path_to_index>, context=0x5ff570) at tree.c:80 #9 0x00007ff631a06a95 in expand_index (istate=0x3dfb00d0100, pl=0x0) at sparse-index.c:422 #10 0x00007ff631a06cbd in ensure_full_index (istate=0x3dfb00d0100) at sparse-index.c:456 #11 0x00007ff631990d08 in index_name_stage_pos (istate=0x3dfb00d0100, name=0x3dfb0020080 "algorithm/levenshtein", namelen=21, stage=0, search_mode=EXPAND_SPARSE) at read-cache.c:556 #12 0x00007ff631990d6c in index_name_pos (istate=0x3dfb00d0100, name=0x3dfb0020080 "algorithm/levenshtein", namelen=21) at read-cache.c:566 #13 0x00007ff63180dbb5 in sanitize_paths (argc=185, argv=0x3dfb0030018, prefix=0x0, skip_checks=0) at builtin/sparse-checkout.c:756 #14 0x00007ff63180de50 in sparse_checkout_set (argc=185, argv=0x3dfb0030018, prefix=0x0) at builtin/sparse-checkout.c:860 #15 0x00007ff63180e6c5 in cmd_sparse_checkout (argc=186, argv=0x3dfb0030018, prefix=0x0) at builtin/sparse-checkout.c:1063 #16 0x00007ff6317234cb in run_builtin (p=0x7ff631ad9b38 <commands+2808>, argc=187, argv=0x3dfb0030018) at git.c:548 #17 0x00007ff6317239c0 in handle_builtin (argc=187, argv=0x3dfb0030018) at git.c:808 #18 0x00007ff631723c7d in run_argv (argcp=0x5ffdd0, argv=0x5ffd78) at git.c:877 #19 0x00007ff6317241d1 in cmd_main (argc=187, argv=0x3dfb0030018) at git.c:1017 #20 0x00007ff631838b60 in main (argc=190, argv=0x3dfb0030000) at common-main.c:64 ``` The very bottom of the stack being the `rehash()` method from `hashmap.c` as called within the `name-hash` API made me look at where these hashmaps were being used in the sparse index logic. These were being copied across indexes, which seems dangerous. Indeed, clearing these hashmaps and setting them as not initialized fixes the segfault. The second commit is a response to a test failure that happens in `t1092-sparse-checkout-compatibility.sh` where `git stash pop` starts to fail because the underlying `git checkout-index` process fails due to colliding files. Passing the `-f` flag appears to work, but it's unclear why this name-hash change causes that change in behavior.
dscho
pushed a commit
that referenced
this pull request
Dec 16, 2024
This one is a little bit more curious. In t6112, we have a test that
exercises the `git rev-list --filter` option with invalid filters. We
execute git-rev-list(1) via `test_must_fail`, which means that we check
for leaks even though Git exits with an error code. This causes the
following leak:
Direct leak of 27 byte(s) in 1 object(s) allocated from:
#0 0x5555555e6946 in realloc.part.0 lsan_interceptors.cpp.o
#1 0x5555558fb4b6 in xrealloc wrapper.c:137:8
#2 0x5555558b6e06 in strbuf_grow strbuf.c:112:2
#3 0x5555558b7550 in strbuf_add strbuf.c:311:2
#4 0x5555557c1a88 in strbuf_addstr strbuf.h:310:2
#5 0x5555557c1d4c in parse_list_objects_filter list-objects-filter-options.c:261:3
#6 0x555555885ead in handle_revision_pseudo_opt revision.c:2899:3
#7 0x555555884e20 in setup_revisions revision.c:3014:11
#8 0x5555556c4b42 in cmd_rev_list builtin/rev-list.c:588:9
#9 0x5555555ec5e3 in run_builtin git.c:483:11
#10 0x5555555eb1e4 in handle_builtin git.c:749:13
#11 0x5555555ec001 in run_argv git.c:819:4
#12 0x5555555eaf94 in cmd_main git.c:954:19
#13 0x5555556fd569 in main common-main.c:64:11
#14 0x7ffff7ca714d in __libc_start_call_main (.../lib/libc.so.6+0x2a14d)
#15 0x7ffff7ca7208 in __libc_start_main@GLIBC_2.2.5 (.../libc.so.6+0x2a208)
#16 0x5555555ad064 in _start (git+0x59064)
This leak is valid, as we call `die()` and do not clean up the memory at
all. But what's curious is that this is the only leak reported, because
we don't clean up any other allocated memory, either, and I have no idea
why the leak sanitizer treats this buffer specially.
In any case, we can work around the leak by shuffling things around a
bit. Instead of calling `gently_parse_list_objects_filter()` and dying
after we have modified the filter spec, we simply do so beforehand. Like
this we don't allocate the buffer in the error case, which makes the
reported leak go away.
It's not pretty, but it manages to make t6112 leak free.
Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
dscho
pushed a commit
that referenced
this pull request
Jan 7, 2025
In 1b9e9be (csum-file.c: use unsafe SHA-1 implementation when available, 2024-09-26) we have converted our `struct hashfile` to use the unsafe SHA1 backend, which results in a significant speedup. One needs to be careful with how to use that structure now though because callers need to consistently use either the safe or unsafe variants of SHA1, as otherwise one can easily trigger corruption. As it turns out, we have one inconsistent usage in our tree because we directly initialize `struct hashfile_checkpoint::ctx` with the safe variant of SHA1, but end up writing to that context with the unsafe ones. This went unnoticed so far because our CI systems do not exercise different hash functions for these two backends, and consequently safe and unsafe variants are equivalent. But when using SHA1DC as safe and OpenSSL as unsafe backend this leads to a crash an t1050: ++ git -c core.compression=0 add large1 AddressSanitizer:DEADLYSIGNAL ================================================================= ==1367==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000040 (pc 0x7ffff7a01a99 bp 0x507000000db0 sp 0x7fffffff5690 T0) ==1367==The signal is caused by a READ memory access. ==1367==Hint: address points to the zero page. #0 0x7ffff7a01a99 in EVP_MD_CTX_copy_ex (/nix/store/h1ydpxkw9qhjdxjpic1pdc2nirggyy6f-openssl-3.3.2/lib/libcrypto.so.3+0x201a99) (BuildId: 41746a580d39075fc85e8c8065b6c07fb34e97d4) #1 0x555555ddde56 in openssl_SHA1_Clone ../sha1/openssl.h:40:2 #2 0x555555dce2fc in git_hash_sha1_clone_unsafe ../object-file.c:123:2 #3 0x555555c2d5f8 in hashfile_checkpoint ../csum-file.c:211:2 #4 0x555555b9905d in deflate_blob_to_pack ../bulk-checkin.c:286:4 #5 0x555555b98ae9 in index_blob_bulk_checkin ../bulk-checkin.c:362:15 #6 0x555555ddab62 in index_blob_stream ../object-file.c:2756:9 #7 0x555555dda420 in index_fd ../object-file.c:2778:9 #8 0x555555ddad76 in index_path ../object-file.c:2796:7 #9 0x555555e947f3 in add_to_index ../read-cache.c:771:7 #10 0x555555e954a4 in add_file_to_index ../read-cache.c:804:9 #11 0x5555558b5c39 in add_files ../builtin/add.c:355:7 #12 0x5555558b412e in cmd_add ../builtin/add.c:578:18 #13 0x555555b1f493 in run_builtin ../git.c:480:11 #14 0x555555b1bfef in handle_builtin ../git.c:740:9 #15 0x555555b1e6f4 in run_argv ../git.c:807:4 #16 0x555555b1b87a in cmd_main ../git.c:947:19 #17 0x5555561649e6 in main ../common-main.c:64:11 #18 0x7ffff742a1fb in __libc_start_call_main (/nix/store/65h17wjrrlsj2rj540igylrx7fqcd6vq-glibc-2.40-36/lib/libc.so.6+0x2a1fb) (BuildId: bf320110569c8ec2425e9a0c5e4eb7e97f1fb6e4) #19 0x7ffff742a2b8 in __libc_start_main@GLIBC_2.2.5 (/nix/store/65h17wjrrlsj2rj540igylrx7fqcd6vq-glibc-2.40-36/lib/libc.so.6+0x2a2b8) (BuildId: bf320110569c8ec2425e9a0c5e4eb7e97f1fb6e4) #20 0x555555772c84 in _start (git+0x21ec84) ==1367==Register values: rax = 0x0000511000001080 rbx = 0x0000000000000000 rcx = 0x000000000000000c rdx = 0x0000000000000000 rdi = 0x0000000000000000 rsi = 0x0000507000000db0 rbp = 0x0000507000000db0 rsp = 0x00007fffffff5690 r8 = 0x0000000000000000 r9 = 0x0000000000000000 r10 = 0x0000000000000000 r11 = 0x00007ffff7a01a30 r12 = 0x0000000000000000 r13 = 0x00007fffffff6b38 r14 = 0x00007ffff7ffd000 r15 = 0x00005555563b9910 AddressSanitizer can not provide additional info. SUMMARY: AddressSanitizer: SEGV (/nix/store/h1ydpxkw9qhjdxjpic1pdc2nirggyy6f-openssl-3.3.2/lib/libcrypto.so.3+0x201a99) (BuildId: 41746a580d39075fc85e8c8065b6c07fb34e97d4) in EVP_MD_CTX_copy_ex ==1367==ABORTING ./test-lib.sh: line 1023: 1367 Aborted git $config add large1 error: last command exited with $?=134 not ok 4 - add with -c core.compression=0 Fix the issue by using the unsafe variant instead. Signed-off-by: Patrick Steinhardt <[email protected]> Signed-off-by: Junio C Hamano <[email protected]>
dscho
pushed a commit
that referenced
this pull request
Jan 7, 2025
Same as with the preceding commit, git-fast-import(1) is using the safe
variant to initialize a hashfile checkpoint. This leads to a segfault
when passing the checkpoint into the hashfile subsystem because it would
use the unsafe variants instead:
++ git --git-dir=R/.git fast-import --big-file-threshold=1
AddressSanitizer:DEADLYSIGNAL
=================================================================
==577126==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000040 (pc 0x7ffff7a01a99 bp 0x5070000009c0 sp 0x7fffffff5b30 T0)
==577126==The signal is caused by a READ memory access.
==577126==Hint: address points to the zero page.
#0 0x7ffff7a01a99 in EVP_MD_CTX_copy_ex (/nix/store/h1ydpxkw9qhjdxjpic1pdc2nirggyy6f-openssl-3.3.2/lib/libcrypto.so.3+0x201a99) (BuildId: 41746a580d39075fc85e8c8065b6c07fb34e97d4)
#1 0x555555ddde56 in openssl_SHA1_Clone ../sha1/openssl.h:40:2
#2 0x555555dce2fc in git_hash_sha1_clone_unsafe ../object-file.c:123:2
#3 0x555555c2d5f8 in hashfile_checkpoint ../csum-file.c:211:2
#4 0x5555559647d1 in stream_blob ../builtin/fast-import.c:1110:2
#5 0x55555596247b in parse_and_store_blob ../builtin/fast-import.c:2031:3
#6 0x555555967f91 in file_change_m ../builtin/fast-import.c:2408:5
#7 0x55555595d8a2 in parse_new_commit ../builtin/fast-import.c:2768:4
#8 0x55555595bb7a in cmd_fast_import ../builtin/fast-import.c:3614:4
#9 0x555555b1f493 in run_builtin ../git.c:480:11
#10 0x555555b1bfef in handle_builtin ../git.c:740:9
#11 0x555555b1e6f4 in run_argv ../git.c:807:4
#12 0x555555b1b87a in cmd_main ../git.c:947:19
#13 0x5555561649e6 in main ../common-main.c:64:11
#14 0x7ffff742a1fb in __libc_start_call_main (/nix/store/65h17wjrrlsj2rj540igylrx7fqcd6vq-glibc-2.40-36/lib/libc.so.6+0x2a1fb) (BuildId: bf320110569c8ec2425e9a0c5e4eb7e97f1fb6e4)
#15 0x7ffff742a2b8 in __libc_start_main@GLIBC_2.2.5 (/nix/store/65h17wjrrlsj2rj540igylrx7fqcd6vq-glibc-2.40-36/lib/libc.so.6+0x2a2b8) (BuildId: bf320110569c8ec2425e9a0c5e4eb7e97f1fb6e4)
#16 0x555555772c84 in _start (git+0x21ec84)
==577126==Register values:
rax = 0x0000511000000cc0 rbx = 0x0000000000000000 rcx = 0x000000000000000c rdx = 0x0000000000000000
rdi = 0x0000000000000000 rsi = 0x00005070000009c0 rbp = 0x00005070000009c0 rsp = 0x00007fffffff5b30
r8 = 0x0000000000000000 r9 = 0x0000000000000000 r10 = 0x0000000000000000 r11 = 0x00007ffff7a01a30
r12 = 0x0000000000000000 r13 = 0x00007fffffff6b60 r14 = 0x00007ffff7ffd000 r15 = 0x00005555563b9910
AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV (/nix/store/h1ydpxkw9qhjdxjpic1pdc2nirggyy6f-openssl-3.3.2/lib/libcrypto.so.3+0x201a99) (BuildId: 41746a580d39075fc85e8c8065b6c07fb34e97d4) in EVP_MD_CTX_copy_ex
==577126==ABORTING
./test-lib.sh: line 1039: 577126 Aborted git --git-dir=R/.git fast-import --big-file-threshold=1 < input
error: last command exited with $?=134
not ok 167 - R: blob bigger than threshold
The segfault is only exposed in case the unsafe and safe backends are
different from one another.
Fix the issue by initializing the context with the unsafe SHA1 variant.
Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
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