[FFmpeg-cvslog] avcodec/mv30: Fix multiple integer overflows
Michael Niedermayer
git at videolan.org
Sat Oct 17 15:41:02 EEST 2020
ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sun Oct 4 19:28:47 2020 +0200| [77cdc684792e6ce0b95a5308d7b61a6906fb5d15] | committer: Michael Niedermayer
avcodec/mv30: Fix multiple integer overflows
Fixes: signed integer overflow: -895002 * 2400 cannot be represented in type 'int'
Fixes: 26052/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MV30_fuzzer-5431812577558528
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=77cdc684792e6ce0b95a5308d7b61a6906fb5d15
---
libavcodec/mv30.c | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)
diff --git a/libavcodec/mv30.c b/libavcodec/mv30.c
index ff60be881d..9f28199478 100644
--- a/libavcodec/mv30.c
+++ b/libavcodec/mv30.c
@@ -198,12 +198,12 @@ static void idct_add(uint8_t *dst, int stride,
static inline void idct2_1d(int *blk, int step)
{
- const int t0 = blk[0 * step];
- const int t1 = blk[1 * step];
- const int t2 = (int)(t1 * 473U) >> 8;
- const int t3 = t2 - t1;
- const int t4 = ((int)(t1 * 362U) >> 8) - t3;
- const int t5 = (((int)(t1 * 277U) >> 8) - t2) + t4;
+ const unsigned int t0 = blk[0 * step];
+ const unsigned int t1 = blk[1 * step];
+ const unsigned int t2 = (int)(t1 * 473U) >> 8;
+ const unsigned int t3 = t2 - t1;
+ const unsigned int t4 = ((int)(t1 * 362U) >> 8) - t3;
+ const unsigned int t5 = (((int)(t1 * 277U) >> 8) - t2) + t4;
blk[0 * step] = t1 + t0;
blk[1 * step] = t0 + t3;
@@ -305,14 +305,14 @@ static int decode_intra_block(AVCodecContext *avctx, int mode,
case 1:
fill = sign_extend(bytestream2_get_ne16(gbyte), 16);
pfill[0] += fill;
- block[0] = ((pfill[0] * qtab[0]) >> 5) + 128;
+ block[0] = ((int)((unsigned)pfill[0] * qtab[0]) >> 5) + 128;
s->bdsp.fill_block_tab[1](dst, block[0], linesize, 8);
break;
case 2:
memset(block, 0, sizeof(*block) * 64);
fill = sign_extend(bytestream2_get_ne16(gbyte), 16);
pfill[0] += fill;
- block[0] = pfill[0] * qtab[0];
+ block[0] = (unsigned)pfill[0] * qtab[0];
block[1] = sign_extend(bytestream2_get_ne16(gbyte), 16) * qtab[1];
block[8] = sign_extend(bytestream2_get_ne16(gbyte), 16) * qtab[8];
block[9] = sign_extend(bytestream2_get_ne16(gbyte), 16) * qtab[9];
@@ -321,7 +321,7 @@ static int decode_intra_block(AVCodecContext *avctx, int mode,
case 3:
fill = sign_extend(bytestream2_get_ne16(gbyte), 16);
pfill[0] += fill;
- block[0] = pfill[0] * qtab[0];
+ block[0] = (unsigned)pfill[0] * qtab[0];
for (int i = 1; i < 64; i++)
block[zigzag[i]] = sign_extend(bytestream2_get_ne16(gbyte), 16) * qtab[zigzag[i]];
idct_put(dst, linesize, block);
@@ -346,14 +346,14 @@ static int decode_inter_block(AVCodecContext *avctx, int mode,
case 1:
fill = sign_extend(bytestream2_get_ne16(gbyte), 16);
pfill[0] += fill;
- block[0] = (pfill[0] * qtab[0]) >> 5;
+ block[0] = (int)((unsigned)pfill[0] * qtab[0]) >> 5;
update_inter_block(dst, linesize, src, in_linesize, block[0]);
break;
case 2:
memset(block, 0, sizeof(*block) * 64);
fill = sign_extend(bytestream2_get_ne16(gbyte), 16);
pfill[0] += fill;
- block[0] = pfill[0] * qtab[0];
+ block[0] = (unsigned)pfill[0] * qtab[0];
block[1] = sign_extend(bytestream2_get_ne16(gbyte), 16) * qtab[1];
block[8] = sign_extend(bytestream2_get_ne16(gbyte), 16) * qtab[8];
block[9] = sign_extend(bytestream2_get_ne16(gbyte), 16) * qtab[9];
@@ -362,7 +362,7 @@ static int decode_inter_block(AVCodecContext *avctx, int mode,
case 3:
fill = sign_extend(bytestream2_get_ne16(gbyte), 16);
pfill[0] += fill;
- block[0] = pfill[0] * qtab[0];
+ block[0] = (unsigned)pfill[0] * qtab[0];
for (int i = 1; i < 64; i++)
block[zigzag[i]] = sign_extend(bytestream2_get_ne16(gbyte), 16) * qtab[zigzag[i]];
idct_add(dst, linesize, src, in_linesize, block);
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