From 90a3055e8bdd9308eceeadc0b37278f324ec6b5d Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Sat, 3 Apr 2010 09:47:01 -0700 Subject: [PATCH] One more sanity check in free. --- ChangeLog | 2 ++ malloc/malloc.c | 15 ++++++++++++++- 2 files changed, 16 insertions(+), 1 deletion(-) diff --git a/ChangeLog b/ChangeLog index f61697c..83e6218 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,7 @@ 2010-04-03 Ulrich Drepper + * malloc/malloc.c (_int_free): Add one more sanity check for fastbins. + * malloc/malloc.c (set_max_fast): Fix computation of the value. 2010-03-30 David S. Miller diff --git a/malloc/malloc.c b/malloc/malloc.c index 784919e..558e8ba 100644 --- a/malloc/malloc.c +++ b/malloc/malloc.c @@ -4852,7 +4852,8 @@ _int_free(mstate av, mchunkptr p) free_perturb (chunk2mem(p), size - SIZE_SZ); set_fastchunks(av); - fb = &fastbin (av, fastbin_index(size)); + unsigned int idx = fastbin_index(size); + fb = &fastbin (av, idx); #ifdef ATOMIC_FASTBINS mchunkptr fd; @@ -4866,6 +4867,12 @@ _int_free(mstate av, mchunkptr p) errstr = "double free or corruption (fasttop)"; goto errout; } + if (old != NULL + && __builtin_expect (fastbin_index(chunksize(old)) != idx, 0)) + { + errstr = "invalid fastbin entry (free)"; + goto errout; + } p->fd = fd = old; } while ((old = catomic_compare_and_exchange_val_rel (fb, p, fd)) != fd); @@ -4877,6 +4884,12 @@ _int_free(mstate av, mchunkptr p) errstr = "double free or corruption (fasttop)"; goto errout; } + if (*fb != NULL + && __builtin_expect (fastbin_index(chunksize(*fb)) != idx, 0)) + { + errstr = "invalid fastbin entry (free)"; + goto errout; + } p->fd = *fb; *fb = p; -- 2.7.4