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| author | DJ Delorie <dj@delorie.com> | 2017-03-17 15:31:38 -0400 |
|---|---|---|
| committer | DJ Delorie <dj@delorie.com> | 2017-03-17 15:31:38 -0400 |
| commit | 17f487b7afa7cd6c316040f3e6c86dc96b2eec30 (patch) | |
| tree | 5836e9e3b024ffd8c45029f7a2934aad44229b71 /malloc/malloc.c | |
| parent | b170d2e7ab998180abbd24fdd6c03ecb4293d000 (diff) | |
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Further harden glibc malloc metadata against 1-byte overflows.
Additional check for chunk_size == next->prev->chunk_size in unlink()
2017-03-17 Chris Evans <scarybeasts@gmail.com>
* malloc/malloc.c (unlink): Add consistency check between size and
next->prev->size, to further harden against 1-byte overflows.
Diffstat (limited to 'malloc/malloc.c')
| -rw-r--r-- | malloc/malloc.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/malloc/malloc.c b/malloc/malloc.c index e29105c372..994a23248e 100644 --- a/malloc/malloc.c +++ b/malloc/malloc.c @@ -1376,6 +1376,8 @@ typedef struct malloc_chunk *mbinptr; /* Take a chunk off a bin list */ #define unlink(AV, P, BK, FD) { \ + if (__builtin_expect (chunksize(P) != prev_size (next_chunk(P)), 0)) \ + malloc_printerr (check_action, "corrupted size vs. prev_size", P, AV); \ FD = P->fd; \ BK = P->bk; \ if (__builtin_expect (FD->bk != P || BK->fd != P, 0)) \ |