avcodec/mpeg4videodec: Fix 2 integer overflows in get_amv()

Fixes: signed integer overflow: -144876608 * 16 cannot be represented in type 'int'
Fixes: 22782/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MPEG4_fuzzer-6039584977977344

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit e361785ee0)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2020-06-11 22:22:57 +02:00
parent fa0a71ac41
commit f823932349

View File

@ -610,7 +610,7 @@ static inline int get_amv(Mpeg4DecContext *ctx, int n)
dy -= 1 << (shift + a + 1);
else
dx -= 1 << (shift + a + 1);
mb_v = s->sprite_offset[0][n] + dx * s->mb_x * 16 + dy * s->mb_y * 16;
mb_v = s->sprite_offset[0][n] + dx * s->mb_x * 16U + dy * s->mb_y * 16U;
sum = 0;
for (y = 0; y < 16; y++) {