avcodec/snowdec: Fix integer overflow with motion vector residual

Fixes: signed integer overflow: -19818 + -2147483648 cannot be represented in type 'int'
Fixes: 9545/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_SNOW_fuzzer-4928769537081344

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 2018-08-20 20:15:19 +02:00
parent 2e23cfbb42
commit acba153a14

View File

@ -208,8 +208,8 @@ static int decode_q_branch(SnowContext *s, int level, int x, int y){
return AVERROR_INVALIDDATA;
}
pred_mv(s, &mx, &my, ref, left, top, tr);
mx+= get_symbol(&s->c, &s->block_state[128 + 32*(mx_context + 16*!!ref)], 1);
my+= get_symbol(&s->c, &s->block_state[128 + 32*(my_context + 16*!!ref)], 1);
mx+= (unsigned)get_symbol(&s->c, &s->block_state[128 + 32*(mx_context + 16*!!ref)], 1);
my+= (unsigned)get_symbol(&s->c, &s->block_state[128 + 32*(my_context + 16*!!ref)], 1);
}
set_blocks(s, level, x, y, l, cb, cr, mx, my, ref, type);
}else{