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[PATCH 2/2][BZ #14547] Fix CVE-2012-4412
- From: Siddhesh Poyarekar <siddhesh at redhat dot com>
- To: libc-alpha at sourceware dot org
- Date: Sun, 30 Jun 2013 22:15:00 +0530
- Subject: [PATCH 2/2][BZ #14547] Fix CVE-2012-4412
Hi,
This is the second patch that completes the fix to CVE-2012-4412. The
reproducer in pr#14547 should be fixed with this patch. I did not
make a test case out of the reproducer since it would be much too
slow.
I have also verified that there are no regressions in the testsuite
due to this fix.
Siddhesh
[BZ #14547]
* string/strcoll_l.c (STRCOLL): Skip allocating memory for
cache if string sizes may cause integer overflow.
diff --git a/string/strcoll_l.c b/string/strcoll_l.c
index 37f802e..ec630fe 100644
--- a/string/strcoll_l.c
+++ b/string/strcoll_l.c
@@ -524,6 +524,14 @@ STRCOLL (const STRING_TYPE *s1, const STRING_TYPE *s2, __locale_t l)
memset (&seq1, 0, sizeof (seq1));
seq2 = seq1;
+ size_t size_max = SIZE_MAX / (sizeof (int32_t) + 1);
+
+ /* If the strings are long enough to cause overflow in the size request, then
+ skip the allocation and proceed with the non-cached routines. */
+ if (MIN (s1len, s2len) > size_max
+ || MAX (s1len, s2len) > size_max - MIN (s1len, s2len))
+ goto begin_collate;
+
if (! __libc_use_alloca ((s1len + s2len) * (sizeof (int32_t) + 1)))
{
seq1.idxarr = (int32_t *) malloc ((s1len + s2len) * (sizeof (int32_t) + 1));
@@ -546,8 +554,10 @@ STRCOLL (const STRING_TYPE *s1, const STRING_TYPE *s2, __locale_t l)
seq2.rulearr = (unsigned char *) alloca (s2len);
}
- int rule = 0;
+ int rule;
+ begin_collate:
+ rule = 0;
/* Cache values in the first pass and if needed, use them in subsequent
passes. */
for (int pass = 0; pass < nrules; ++pass)