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| author | Michael Niedermayer <michael@niedermayer.cc> | 2019-07-04 23:13:13 +0200 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2020-07-01 12:11:55 +0200 |
| commit | 4ef3aafa835442a7499c4c455fcc9255aaa98a53 (patch) | |
| tree | 385d12d98681370535ee71462e2154e13cff0f07 | |
| parent | af988e8b8d8775b7010d9bf3914f3e3d40d42ab9 (diff) | |
| download | ffmpeg-4ef3aafa835442a7499c4c455fcc9255aaa98a53.tar.gz | |
avcodec/vc1_block: Fix integer overflow in ff_vc1_pred_dc()
Fixes: signed integer overflow: 32796 * 65536 cannot be represented in type 'int'
Fixes: 15430/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_VC1IMAGE_fuzzer-5735424087031808
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 f31ed8f3b00ec7afe87092798bf0b397f6e19ed5)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
| -rw-r--r-- | libavcodec/vc1_block.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/libavcodec/vc1_block.c b/libavcodec/vc1_block.c index 45760cc6ee..9fe12a40ff 100644 --- a/libavcodec/vc1_block.c +++ b/libavcodec/vc1_block.c @@ -411,12 +411,12 @@ static inline int ff_vc1_pred_dc(MpegEncContext *s, int overlap, int pq, int n, if (c_avail && (n != 1 && n != 3)) { q2 = s->current_picture.qscale_table[mb_pos - 1]; if (q2 && q2 != q1) - c = (c * s->y_dc_scale_table[q2] * ff_vc1_dqscale[dqscale_index] + 0x20000) >> 18; + c = (int)((unsigned)c * s->y_dc_scale_table[q2] * ff_vc1_dqscale[dqscale_index] + 0x20000) >> 18; } if (a_avail && (n != 2 && n != 3)) { q2 = s->current_picture.qscale_table[mb_pos - s->mb_stride]; if (q2 && q2 != q1) - a = (a * s->y_dc_scale_table[q2] * ff_vc1_dqscale[dqscale_index] + 0x20000) >> 18; + a = (int)((unsigned)a * s->y_dc_scale_table[q2] * ff_vc1_dqscale[dqscale_index] + 0x20000) >> 18; } if (a_avail && c_avail && (n != 3)) { int off = mb_pos; @@ -426,7 +426,7 @@ static inline int ff_vc1_pred_dc(MpegEncContext *s, int overlap, int pq, int n, off -= s->mb_stride; q2 = s->current_picture.qscale_table[off]; if (q2 && q2 != q1) - b = (b * s->y_dc_scale_table[q2] * ff_vc1_dqscale[dqscale_index] + 0x20000) >> 18; + b = (int)((unsigned)b * s->y_dc_scale_table[q2] * ff_vc1_dqscale[dqscale_index] + 0x20000) >> 18; } if (c_avail && (!a_avail || abs(a - b) <= abs(b - c))) { |