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authorArjun Shankar <arjun@redhat.com>2017-11-30 13:31:45 +0100
committerArjun Shankar <arjun@redhat.com>2017-11-30 13:42:53 +0100
commit34697694e8a93b325b18f25f7dcded55d6baeaf6 (patch)
tree694ad7ce28c06d16baff488f97f09e46d373564a /malloc
parent18305fba5575a09063652014cfc483b898d8bdcd (diff)
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Fix integer overflow in malloc when tcache is enabled [BZ #22375]
When the per-thread cache is enabled, __libc_malloc uses request2size (which does not perform an overflow check) to calculate the chunk size from the requested allocation size. This leads to an integer overflow causing malloc to incorrectly return the last successfully allocated block when called with a very large size argument (close to SIZE_MAX). This commit uses checked_request2size instead, removing the overflow.
Diffstat (limited to 'malloc')
-rw-r--r--malloc/malloc.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/malloc/malloc.c b/malloc/malloc.c
index 79f0e9eac74..0c9e0748b4c 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -3031,7 +3031,8 @@ __libc_malloc (size_t bytes)
return (*hook)(bytes, RETURN_ADDRESS (0));
#if USE_TCACHE
/* int_free also calls request2size, be careful to not pad twice. */
- size_t tbytes = request2size (bytes);
+ size_t tbytes;
+ checked_request2size (bytes, tbytes);
size_t tc_idx = csize2tidx (tbytes);
MAYBE_INIT_TCACHE ();