diff options
| author | joseph <joseph@7b3dc134-2b1b-0410-93df-9e9f96275f8d> | 2014-01-22 03:30:43 +0000 |
|---|---|---|
| committer | joseph <joseph@7b3dc134-2b1b-0410-93df-9e9f96275f8d> | 2014-01-22 03:30:43 +0000 |
| commit | 56b544bde89ca5d99b49b4a0ec0bf655a4247e11 (patch) | |
| tree | 923c5ac449b3c0868877b87f87b117091639cd8f | |
| parent | f9b527c6d1573e0530905fd8b12e874d08974658 (diff) | |
Merge changes between r23796 and r25089 from /fsf/glibc-2_17-branch.
git-svn-id: svn://svn.eglibc.org/branches/eglibc-2_17@25090 7b3dc134-2b1b-0410-93df-9e9f96275f8d
| -rw-r--r-- | libc/ChangeLog | 7 | ||||
| -rw-r--r-- | libc/NEWS | 2 | ||||
| -rw-r--r-- | libc/malloc/malloc.c | 20 |
3 files changed, 20 insertions, 9 deletions
diff --git a/libc/ChangeLog b/libc/ChangeLog index b76e7dc06..49bf8f900 100644 --- a/libc/ChangeLog +++ b/libc/ChangeLog @@ -1,3 +1,10 @@ +2014-01-04 Maxim Kuvyrkov <maxim@kugelworks.com> + Ondřej Bílka <neleai@seznam.cz> + + [BZ #15073] + * malloc/malloc.c (_int_free): Perform sanity check only if we + have_lock. + 2013-02-08 Carlos O'Donell <carlos@redhat.com> [BZ #15006] @@ -8,7 +8,7 @@ using `glibc' in the "product" field. Version 2.17.1 * The following bugs are resolved with this release: - 15003, 15006, 15122, 15759. + 15003, 15006, 15073, 15122, 15759. Version 2.17 diff --git a/libc/malloc/malloc.c b/libc/malloc/malloc.c index 3f0b6b1cd..acf3d4202 100644 --- a/libc/malloc/malloc.c +++ b/libc/malloc/malloc.c @@ -3816,25 +3816,29 @@ _int_free(mstate av, mchunkptr p, int have_lock) unsigned int idx = fastbin_index(size); fb = &fastbin (av, idx); - mchunkptr fd; - mchunkptr old = *fb; + /* Atomically link P to its fastbin: P->FD = *FB; *FB = P; */ + mchunkptr old = *fb, old2; unsigned int old_idx = ~0u; do { - /* Another simple check: make sure the top of the bin is not the - record we are going to add (i.e., double free). */ + /* Check that the top of the bin is not the record we are going to add + (i.e., double free). */ if (__builtin_expect (old == p, 0)) { errstr = "double free or corruption (fasttop)"; goto errout; } - if (old != NULL) + /* Check that size of fastbin chunk at the top is the same as + size of the chunk that we are adding. We can dereference OLD + only if we have the lock, otherwise it might have already been + deallocated. See use of OLD_IDX below for the actual check. */ + if (have_lock && old != NULL) old_idx = fastbin_index(chunksize(old)); - p->fd = fd = old; + p->fd = old2 = old; } - while ((old = catomic_compare_and_exchange_val_rel (fb, p, fd)) != fd); + while ((old = catomic_compare_and_exchange_val_rel (fb, p, old2)) != old2); - if (fd != NULL && __builtin_expect (old_idx != idx, 0)) + if (have_lock && old != NULL && __builtin_expect (old_idx != idx, 0)) { errstr = "invalid fastbin entry (free)"; goto errout; |