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authorMichael Niedermayer <michael@niedermayer.cc>2019-07-04 23:13:13 +0200
committerMichael Niedermayer <michael@niedermayer.cc>2019-11-15 12:25:45 +0100
commit06ad82980087589f91cdfc03614b7319dd24613c (patch)
tree99ca36d3cf75256976310f9ad0ef8df66b31baa4
parent9ba145e243cbde7539263b8fcd79c52e06b33da7 (diff)
downloadffmpeg-06ad82980087589f91cdfc03614b7319dd24613c.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.c6
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))) {