From 49c3c37651e2d2ec4ff8ce21252bbbc08a9d6639 Mon Sep 17 00:00:00 2001 From: Eyal Itkin Date: Tue, 31 Mar 2020 02:00:14 -0400 Subject: [PATCH] Fix alignment bug in Safe-Linking Alignment checks should be performed on the user's buffer and NOT on the mchunkptr as was done before. This caused bugs in 32 bit versions, because: 2*sizeof(t) != MALLOC_ALIGNMENT. As the tcache works on users' buffers it uses the aligned_OK() check, and the rest work on mchunkptr and therefore check using misaligned_chunk(). Reviewed-by: Carlos O'Donell --- malloc/malloc.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/malloc/malloc.c b/malloc/malloc.c index 0e4acb22f6..6acb5ad43a 100644 --- a/malloc/malloc.c +++ b/malloc/malloc.c @@ -2169,7 +2169,7 @@ do_check_malloc_state (mstate av) while (p != 0) { - if (__glibc_unlikely (!aligned_OK (p))) + if (__glibc_unlikely (misaligned_chunk (p))) malloc_printerr ("do_check_malloc_state(): " "unaligned fastbin chunk detected"); /* each chunk claims to be inuse */ @@ -2949,11 +2949,11 @@ static __always_inline void * tcache_get (size_t tc_idx) { tcache_entry *e = tcache->entries[tc_idx]; + if (__glibc_unlikely (!aligned_OK (e))) + malloc_printerr ("malloc(): unaligned tcache chunk detected"); tcache->entries[tc_idx] = REVEAL_PTR (e->next); --(tcache->counts[tc_idx]); e->key = NULL; - if (__glibc_unlikely (!aligned_OK (e))) - malloc_printerr ("malloc(): unaligned tcache chunk detected"); return (void *) e; } @@ -3591,7 +3591,7 @@ _int_malloc (mstate av, size_t bytes) if (victim == NULL) \ break; \ pp = REVEAL_PTR (victim->fd); \ - if (__glibc_unlikely (!aligned_OK (pp))) \ + if (__glibc_unlikely (pp != NULL && misaligned_chunk (pp))) \ malloc_printerr ("malloc(): unaligned fastbin chunk detected"); \ } \ while ((pp = catomic_compare_and_exchange_val_acq (fb, pp, victim)) \ @@ -3606,8 +3606,8 @@ _int_malloc (mstate av, size_t bytes) if (victim != NULL) { - if (__glibc_unlikely (!aligned_OK (victim))) - malloc_printerr ("malloc(): unaligned fastbin chunk detected"); + if (__glibc_unlikely (misaligned_chunk (victim))) + malloc_printerr ("malloc(): unaligned fastbin chunk detected 2"); if (SINGLE_THREAD_P) *fb = REVEAL_PTR (victim->fd); @@ -3631,8 +3631,8 @@ _int_malloc (mstate av, size_t bytes) while (tcache->counts[tc_idx] < mp_.tcache_count && (tc_victim = *fb) != NULL) { - if (__glibc_unlikely (!aligned_OK (tc_victim))) - malloc_printerr ("malloc(): unaligned fastbin chunk detected"); + if (__glibc_unlikely (misaligned_chunk (tc_victim))) + malloc_printerr ("malloc(): unaligned fastbin chunk detected 3"); if (SINGLE_THREAD_P) *fb = REVEAL_PTR (tc_victim->fd); else @@ -4505,7 +4505,7 @@ static void malloc_consolidate(mstate av) if (p != 0) { do { { - if (__glibc_unlikely (!aligned_OK (p))) + if (__glibc_unlikely (misaligned_chunk (p))) malloc_printerr ("malloc_consolidate(): " "unaligned fastbin chunk detected"); @@ -4937,7 +4937,7 @@ int_mallinfo (mstate av, struct mallinfo *m) p != 0; p = REVEAL_PTR (p->fd)) { - if (__glibc_unlikely (!aligned_OK (p))) + if (__glibc_unlikely (misaligned_chunk (p))) malloc_printerr ("int_mallinfo(): " "unaligned fastbin chunk detected"); ++nfastblocks; @@ -5479,7 +5479,7 @@ __malloc_info (int options, FILE *fp) while (p != NULL) { - if (__glibc_unlikely (!aligned_OK (p))) + if (__glibc_unlikely (misaligned_chunk (p))) malloc_printerr ("__malloc_info(): " "unaligned fastbin chunk detected"); ++nthissize; -- 2.43.5