avcodec/diracdec: Fix integer overflow in global_mv()

Fixes: signed integer overflow: 16384 * 196607 cannot be represented in type 'int'
Fixes: 14810/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_DIRAC_fuzzer-5091232683917312

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2019-05-22 02:01:33 +02:00
parent 0a2b768d3e
commit a99ffb5bb4

View File

@ -1433,8 +1433,8 @@ 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) + (1<<ez) * b[0]);
int64_t my = m * (int64_t)((A[1][0] * (int64_t)x + A[1][1]*(int64_t)y) + (1<<ez) * b[1]);
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]);
block->u.mv[ref][0] = (mx + (1<<(ez+ep))) >> (ez+ep);
block->u.mv[ref][1] = (my + (1<<(ez+ep))) >> (ez+ep);