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| author | Michael Niedermayer <michael@niedermayer.cc> | 2019-04-16 00:09:38 +0200 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2019-04-24 17:05:02 +0200 |
| commit | 6f0e9a863466bfcbd75ee15d4d8a6aad2a5126a4 (patch) | |
| tree | 40719c4f05e685157225d9b76ab7e09331b2c5f8 /libavutil/avstring.c | |
| parent | 18a567c369d74af5ef651b07c4c5615f5598616b (diff) | |
| download | ffmpeg-6f0e9a863466bfcbd75ee15d4d8a6aad2a5126a4.tar.gz | |
avutil/avstring: Fix bug and undefined behavior in av_strncasecmp()
The function in case of n=0 would read more bytes than 0.
The end pointer could be beyond the allocated space, which
is undefined.
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Diffstat (limited to 'libavutil/avstring.c')
| -rw-r--r-- | libavutil/avstring.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/libavutil/avstring.c b/libavutil/avstring.c index f03dd25141..4c068f5bc5 100644 --- a/libavutil/avstring.c +++ b/libavutil/avstring.c @@ -222,12 +222,13 @@ int av_strcasecmp(const char *a, const char *b) int av_strncasecmp(const char *a, const char *b, size_t n) { - const char *end = a + n; uint8_t c1, c2; + if (n <= 0) + return 0; do { c1 = av_tolower(*a++); c2 = av_tolower(*b++); - } while (a < end && c1 && c1 == c2); + } while (--n && c1 && c1 == c2); return c1 - c2; } |