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| author | Szabolcs Nagy <szabolcs.nagy@arm.com> | 2022-10-11 15:24:41 +0100 |
|---|---|---|
| committer | Szabolcs Nagy <szabolcs.nagy@arm.com> | 2022-11-02 15:42:27 +0000 |
| commit | 17bfe5954baee1f18672aea94caa1126ec36fb81 (patch) | |
| tree | 985ff73ad29bc4cc4e15ce6d182ecd808b7b02d7 /stdlib | |
| parent | 7457b7eef8dfe8cc48e55b9f9837df6dd397b80d (diff) | |
| download | glibc-17bfe5954baee1f18672aea94caa1126ec36fb81.zip glibc-17bfe5954baee1f18672aea94caa1126ec36fb81.tar.gz glibc-17bfe5954baee1f18672aea94caa1126ec36fb81.tar.bz2 | |
Fix OOB read in stdlib thousand grouping parsing [BZ #29727]
__correctly_grouped_prefixmb only worked with thousands_len == 1,
otherwise it read past the end of cp or thousands.
This affects scanf formats like %'d, %'f and the internal but
exposed __strto{l,ul,f,d,..}_internal with grouping flag set
and an LC_NUMERIC locale where thousands_len > 1.
Avoid OOB access by considering thousands_len when initializing cp.
This fixes bug 29727.
Found by the morello port with strict bounds checking where
FAIL: stdlib/tst-strtod4
FAIL: stdlib/tst-strtod5i
crashed using a locale with thousands_len==3.
Diffstat (limited to 'stdlib')
| -rw-r--r-- | stdlib/grouping.c | 16 |
1 files changed, 7 insertions, 9 deletions
diff --git a/stdlib/grouping.c b/stdlib/grouping.c index be7922f..06cbe7b 100644 --- a/stdlib/grouping.c +++ b/stdlib/grouping.c @@ -52,21 +52,19 @@ __correctly_grouped_prefixmb (const STRING_TYPE *begin, const STRING_TYPE *end, #endif const char *grouping) { -#ifndef USE_WIDE_CHAR - size_t thousands_len; - int cnt; -#endif - if (grouping == NULL) return end; -#ifndef USE_WIDE_CHAR - thousands_len = strlen (thousands); +#ifdef USE_WIDE_CHAR + size_t thousands_len = 1; +#else + size_t thousands_len = strlen (thousands); + int cnt; #endif - while (end > begin) + while (end - begin >= thousands_len) { - const STRING_TYPE *cp = end - 1; + const STRING_TYPE *cp = end - thousands_len; const char *gp = grouping; /* Check first group. */ |