[FFmpeg-devel] [PATCH 3/4] avcodec/simple_idct_template: Fix several integer overflows
Michael Niedermayer
michael at niedermayer.cc
Mon Mar 13 04:36:36 EET 2017
Benchmarks with START_TIMER indicate that the code is faster with unsigned, (that is
with the patch), there was quite some fluctuation in the numbers so this may be just
random
Fixes: 811/clusterfuzz-testcase-6465493076541440
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
libavcodec/simple_idct_template.c | 36 ++++++++++++++++++------------------
1 file changed, 18 insertions(+), 18 deletions(-)
diff --git a/libavcodec/simple_idct_template.c b/libavcodec/simple_idct_template.c
index f5744e0a39..c669767761 100644
--- a/libavcodec/simple_idct_template.c
+++ b/libavcodec/simple_idct_template.c
@@ -112,7 +112,7 @@ static inline void FUNC(idctRowCondDC_extrashift)(int16_t *row, int extra_shift)
static inline void FUNC(idctRowCondDC)(int16_t *row, int extra_shift)
#endif
{
- int a0, a1, a2, a3, b0, b1, b2, b3;
+ SUINT a0, a1, a2, a3, b0, b1, b2, b3;
#if HAVE_FAST_64BIT
#define ROW0_MASK (0xffffLL << 48 * HAVE_BIGENDIAN)
@@ -187,14 +187,14 @@ static inline void FUNC(idctRowCondDC)(int16_t *row, int extra_shift)
MAC(b3, -W1, row[7]);
}
- row[0] = (a0 + b0) >> (ROW_SHIFT + extra_shift);
- row[7] = (a0 - b0) >> (ROW_SHIFT + extra_shift);
- row[1] = (a1 + b1) >> (ROW_SHIFT + extra_shift);
- row[6] = (a1 - b1) >> (ROW_SHIFT + extra_shift);
- row[2] = (a2 + b2) >> (ROW_SHIFT + extra_shift);
- row[5] = (a2 - b2) >> (ROW_SHIFT + extra_shift);
- row[3] = (a3 + b3) >> (ROW_SHIFT + extra_shift);
- row[4] = (a3 - b3) >> (ROW_SHIFT + extra_shift);
+ row[0] = (int)(a0 + b0) >> (ROW_SHIFT + extra_shift);
+ row[7] = (int)(a0 - b0) >> (ROW_SHIFT + extra_shift);
+ row[1] = (int)(a1 + b1) >> (ROW_SHIFT + extra_shift);
+ row[6] = (int)(a1 - b1) >> (ROW_SHIFT + extra_shift);
+ row[2] = (int)(a2 + b2) >> (ROW_SHIFT + extra_shift);
+ row[5] = (int)(a2 - b2) >> (ROW_SHIFT + extra_shift);
+ row[3] = (int)(a3 + b3) >> (ROW_SHIFT + extra_shift);
+ row[4] = (int)(a3 - b3) >> (ROW_SHIFT + extra_shift);
}
#define IDCT_COLS do { \
@@ -253,25 +253,25 @@ static inline void FUNC(idctSparseCol_extrashift)(int16_t *col)
static inline void FUNC(idctSparseColPut)(pixel *dest, int line_size,
int16_t *col)
{
- int a0, a1, a2, a3, b0, b1, b2, b3;
+ SUINT a0, a1, a2, a3, b0, b1, b2, b3;
IDCT_COLS;
- dest[0] = av_clip_pixel((a0 + b0) >> COL_SHIFT);
+ dest[0] = av_clip_pixel((int)(a0 + b0) >> COL_SHIFT);
dest += line_size;
- dest[0] = av_clip_pixel((a1 + b1) >> COL_SHIFT);
+ dest[0] = av_clip_pixel((int)(a1 + b1) >> COL_SHIFT);
dest += line_size;
- dest[0] = av_clip_pixel((a2 + b2) >> COL_SHIFT);
+ dest[0] = av_clip_pixel((int)(a2 + b2) >> COL_SHIFT);
dest += line_size;
- dest[0] = av_clip_pixel((a3 + b3) >> COL_SHIFT);
+ dest[0] = av_clip_pixel((int)(a3 + b3) >> COL_SHIFT);
dest += line_size;
- dest[0] = av_clip_pixel((a3 - b3) >> COL_SHIFT);
+ dest[0] = av_clip_pixel((int)(a3 - b3) >> COL_SHIFT);
dest += line_size;
- dest[0] = av_clip_pixel((a2 - b2) >> COL_SHIFT);
+ dest[0] = av_clip_pixel((int)(a2 - b2) >> COL_SHIFT);
dest += line_size;
- dest[0] = av_clip_pixel((a1 - b1) >> COL_SHIFT);
+ dest[0] = av_clip_pixel((int)(a1 - b1) >> COL_SHIFT);
dest += line_size;
- dest[0] = av_clip_pixel((a0 - b0) >> COL_SHIFT);
+ dest[0] = av_clip_pixel((int)(a0 - b0) >> COL_SHIFT);
}
static inline void FUNC(idctSparseColAdd)(pixel *dest, int line_size,
--
2.11.0
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