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| author | Michael Niedermayer <michael@niedermayer.cc> | 2015-12-01 13:32:31 +0100 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2015-12-02 21:38:11 +0100 |
| commit | f03c2ceec174877e03bb302f5971fbe9ffbe4856 (patch) | |
| tree | c58b5eeb6f1e8624bdf59bf970b4c118461a6fd7 /libavutil/mathematics.c | |
| parent | cd7524fdd13dc8d0cf22e2cfd8300a245542b13a (diff) | |
| download | ffmpeg-f03c2ceec174877e03bb302f5971fbe9ffbe4856.tar.gz | |
avutil/mathematics: return INT64_MIN (=AV_NOPTS_VALUE) from av_rescale_rnd() for overflows
Fixes integer overflow
Fixes: mozilla bug 1229167
Found-by: Tyson Smith
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Diffstat (limited to 'libavutil/mathematics.c')
| -rw-r--r-- | libavutil/mathematics.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/libavutil/mathematics.c b/libavutil/mathematics.c index 689325fe4b..c12c73e6e6 100644 --- a/libavutil/mathematics.c +++ b/libavutil/mathematics.c @@ -72,7 +72,7 @@ int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding rnd) } if (a < 0) - return -av_rescale_rnd(-FFMAX(a, -INT64_MAX), b, c, rnd ^ ((rnd >> 1) & 1)); + return -(uint64_t)av_rescale_rnd(-FFMAX(a, -INT64_MAX), b, c, rnd ^ ((rnd >> 1) & 1)); if (rnd == AV_ROUND_NEAR_INF) r = c / 2; @@ -82,8 +82,13 @@ int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding rnd) if (b <= INT_MAX && c <= INT_MAX) { if (a <= INT_MAX) return (a * b + r) / c; - else - return a / c * b + (a % c * b + r) / c; + else { + int64_t ad = a / c; + int64_t a2 = (a % c * b + r) / c; + if (ad >= INT32_MAX && ad > (INT64_MAX - a2) / b) + return INT64_MIN; + return ad * b + a2; + } } else { #if 1 uint64_t a0 = a & 0xFFFFFFFF; @@ -107,6 +112,8 @@ int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding rnd) t1++; } } + if (t1 > INT64_MAX) + return INT64_MIN; return t1; } #else |