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mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-23 12:43:46 +02:00

avcodec/diracdec: avoid signed integer overflow in global mv

Fixes: signed integer overflow: -128275513086 * -76056576 cannot be represented in type 'long'
Fixes: 45818/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_DIRAC_fuzzer-5129799149944832

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 7f1279684e)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2022-03-21 20:51:47 +01:00
parent 8ed50e1838
commit 73c593b0ce

View File

@ -1411,8 +1411,8 @@ static void global_mv(DiracContext *s, DiracBlock *block, int x, int y, int ref)
int *c = s->globalmc[ref].perspective;
int64_t m = (1<<ep) - (c[0]*(int64_t)x + c[1]*(int64_t)y);
int64_t mx = m * (int64_t)((A[0][0] * (int64_t)x + A[0][1]*(int64_t)y) + (1LL<<ez) * b[0]);
int64_t my = m * (int64_t)((A[1][0] * (int64_t)x + A[1][1]*(int64_t)y) + (1LL<<ez) * b[1]);
int64_t mx = m * (uint64_t)((A[0][0] * (int64_t)x + A[0][1]*(int64_t)y) + (1LL<<ez) * b[0]);
int64_t my = m * (uint64_t)((A[1][0] * (int64_t)x + A[1][1]*(int64_t)y) + (1LL<<ez) * b[1]);
block->u.mv[ref][0] = (mx + (1<<(ez+ep))) >> (ez+ep);
block->u.mv[ref][1] = (my + (1<<(ez+ep))) >> (ez+ep);