Crash in test suite x509write config full no seedfile

[mpg]

Steps to reproduce:

find . -name seedfile -exec rm {} +
scripts/config.py config full
(cd tests && make test_suite_x509write && ./test_suite_x509write)

Observed behaviour: the first few tests fail, then eventually there's a bus error and a core dump is produced. If we just add the seedfile again (dd if=/dev/urandom of=./tests/seedfile bs=64 count=1) everything passes and there is no crash.

Expected behaviour: it is known limitation of our test system that we have to generate a seedfile before running the tests. However, the absence of a seedfile should only result in tests failing, not in the whole process crashing. This might be the sign of a deeper issue.

With ASan and debug info (see CMake build type ASanDbg):

Certificate Request check Server1 SHA1 ............................ AddressSanitizer:DEADLYSIGNAL
=================================================================
==755975==ERROR: AddressSanitizer: SEGV on unknown address 0x000000010030 (pc 0x0000004eba8d bp 0x7fffe048cfb0 sp 0x7fffe048cf90 T0)
==755975==The signal is caused by a READ memory access.
    #0 0x4eba8d in mbedtls_asn1_free_named_data_list /home/manpeg01/src/mbedtls/library/asn1parse.c
    #1 0x4e847b in mbedtls_x509write_csr_free /home/manpeg01/src/mbedtls/library/x509write_csr.c:62:5
    #2 0x4c3536 in test_x509_csr_check /home/manpeg01/src/mbedtls/tests/suites/test_suite_x509write.function:161:5
    #3 0x4c3d87 in test_x509_csr_check_wrapper /home/manpeg01/src/mbedtls/tests/suites/test_suite_x509write.function:169:5
    #4 0x4c6c3f in dispatch_test /home/manpeg01/src/mbedtls/tests/suites/main_test.function:174:17
    #5 0x4c8053 in execute_tests /home/manpeg01/src/mbedtls/tests/suites/host_test.function:711:31
    #6 0x4ca31d in main /home/manpeg01/src/mbedtls/tests/suites/main_test.function:257:11
    #7 0x7f60d903a082 in __libc_start_main /build/glibc-SzIz7B/glibc-2.31/csu/../csu/libc-start.c:308:16
    #8 0x41b40d in _start (/home/manpeg01/src/mbedtls/tests/test_suite_x509write+0x41b40d)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV /home/manpeg01/src/mbedtls/library/asn1parse.c in mbedtls_asn1_free_named_data_list

[mpg]

Note: I noticed this while working on driver-only builds, so I'm adding this to the corresponding EPIC - let's fix this before any work on driver-only X.509 write so that it doesn't become a distraction in the middle of other work.

[superna9999]

mbedtls_x509write_csr_free crashes on an unitialized mbedtls_x509write_csr in x509_csr_check_opaque() no idea why it doesn't in x509_csr_check()