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| author | Michael Niedermayer <michael@niedermayer.cc> | 2017-08-17 01:06:14 +0200 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2017-08-29 21:16:32 +0200 |
| commit | 6def8b8d924af985514ebb1b1a51871c94d26d33 (patch) | |
| tree | eeb42aa09eb99816d09c814f8ca58004c167e2a2 | |
| parent | 429f3266c14ac4851da007fcb3461f9acc99cbad (diff) | |
| download | ffmpeg-6def8b8d924af985514ebb1b1a51871c94d26d33.tar.gz | |
avcodec/h264idct_template: Fix integer overflow in ff_h264_idct8_add()
Fixes: 2891/clusterfuzz-testcase-minimized-5881795457318912
Fixes: runtime error: signed integer overflow: 1551827968 - -775913984 cannot be represented in type 'int'
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
| -rw-r--r-- | libavcodec/h264idct_template.c | 28 |
1 files changed, 14 insertions, 14 deletions
diff --git a/libavcodec/h264idct_template.c b/libavcodec/h264idct_template.c index 288107d5a4..3ad58c4a11 100644 --- a/libavcodec/h264idct_template.c +++ b/libavcodec/h264idct_template.c @@ -76,20 +76,20 @@ void FUNCC(ff_h264_idct8_add)(uint8_t *_dst, int16_t *_block, int stride){ for( i = 0; i < 8; i++ ) { - const int a0 = block[i+0*8] + block[i+4*8]; - const int a2 = block[i+0*8] - block[i+4*8]; - const int a4 = (block[i+2*8]>>1) - block[i+6*8]; - const int a6 = (block[i+6*8]>>1) + block[i+2*8]; - - const int b0 = a0 + a6; - const int b2 = a2 + a4; - const int b4 = a2 - a4; - const int b6 = a0 - a6; - - const int a1 = -block[i+3*8] + block[i+5*8] - block[i+7*8] - (block[i+7*8]>>1); - const int a3 = block[i+1*8] + block[i+7*8] - block[i+3*8] - (block[i+3*8]>>1); - const int a5 = -block[i+1*8] + block[i+7*8] + block[i+5*8] + (block[i+5*8]>>1); - const int a7 = block[i+3*8] + block[i+5*8] + block[i+1*8] + (block[i+1*8]>>1); + const unsigned int a0 = block[i+0*8] + block[i+4*8]; + const unsigned int a2 = block[i+0*8] - block[i+4*8]; + const unsigned int a4 = (block[i+2*8]>>1) - block[i+6*8]; + const unsigned int a6 = (block[i+6*8]>>1) + block[i+2*8]; + + const unsigned int b0 = a0 + a6; + const unsigned int b2 = a2 + a4; + const unsigned int b4 = a2 - a4; + const unsigned int b6 = a0 - a6; + + const int a1 = -block[i+3*8] + (unsigned)block[i+5*8] - block[i+7*8] - (block[i+7*8]>>1); + const int a3 = block[i+1*8] + (unsigned)block[i+7*8] - block[i+3*8] - (block[i+3*8]>>1); + const int a5 = -block[i+1*8] + (unsigned)block[i+7*8] + block[i+5*8] + (block[i+5*8]>>1); + const int a7 = block[i+3*8] + (unsigned)block[i+5*8] + block[i+1*8] + (block[i+1*8]>>1); const int b1 = (a7>>2) + a1; const int b3 = a3 + (a5>>2); |