avcodec/svq3: Fix overflow in svq3_add_idct_c()

Fixes: runtime error: signed integer overflow: 2147392585 + 524288 cannot be represented in type 'int'
Fixes: 3348/clusterfuzz-testcase-minimized-4809500517203968

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 2017-09-18 17:03:55 +02:00
parent f160a63bad
commit 2c933c5168

View File

@ -285,7 +285,7 @@ static void svq3_add_idct_c(uint8_t *dst, int16_t *block,
const unsigned z1 = 13 * (block[i + 4 * 0] - block[i + 4 * 2]);
const unsigned z2 = 7 * block[i + 4 * 1] - 17 * block[i + 4 * 3];
const unsigned z3 = 17 * block[i + 4 * 1] + 7 * block[i + 4 * 3];
const int rr = (dc + 0x80000);
const int rr = (dc + 0x80000u);
dst[i + stride * 0] = av_clip_uint8(dst[i + stride * 0] + ((int)((z0 + z3) * qmul + rr) >> 20));
dst[i + stride * 1] = av_clip_uint8(dst[i + stride * 1] + ((int)((z1 + z2) * qmul + rr) >> 20));