ospf6d: fix backlink check (backport #9016) #9125
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This code has been wrong ~ever (according to git history). There are 3 conditional blocks with the added assertion that both the LSA and the vertex being checked can't both be network LSAs. The third block is clearly assuming both LSA and vertex are router LSAs b/c it is accessing the backlink and lsdesc as router lsdesc's also making sure both are p2p links (which they would have to be to point at each other). The programming error here is that (A && B) == False does NOT imply !A, but the code is written that way. So we end up in the third block one of LSA or vertex being network LSAs rather easily (whenever that is the case and the desc isn't the backlink being sought). This was caught by ASAN b/c the lsdesc and backlinks are being accessed (> 4 byte field offsets) as if they were router lsdesc's in the third block, when in fact one of them is a network lsdesc which is only 4 bytes long -- so ASAN flags the access beyond bounds. Signed-off-by: Christian Hopps <[email protected]> (cherry picked from commit ff2052e)
Continuous Integration Result: SUCCESSFULCongratulations, this patch passed basic tests Tested-by: NetDEF / OpenSourceRouting.org CI System CI System Testrun URL: https://ci1.netdef.org/browse/FRR-FRRPULLREQ-20436/ This is a comment from an automated CI system. |
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This is an automatic backport of pull request #9016 done by Mergify.
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