diff mbox series

[FFmpeg-devel,3/7] swscale/swscale: Use unsigned operation to avoid undefined behavior

Message ID 20240912233337.2444412-3-michael@niedermayer.cc
State New
Headers show
Series [FFmpeg-devel,1/7] avformat/mov_chan: Check for FF_SANE_NB_CHANNELS | expand

Checks

Context Check Description
yinshiyou/make_loongarch64 success Make finished
yinshiyou/make_fate_loongarch64 success Make fate finished
andriy/make_x86 success Make finished
andriy/make_fate_x86 success Make fate finished

Commit Message

Michael Niedermayer Sept. 12, 2024, 11:33 p.m. UTC 
I have not checked that the constant is correct, this just fixes the undefined behavior

Fixes: signed integer overflow: -646656 * 3517 cannot be represented in type 'int
Fixes: 70559/clusterfuzz-testcase-minimized-ffmpeg_SWS_fuzzer-5209368631508992

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libswscale/swscale.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/libswscale/swscale.c b/libswscale/swscale.c
index df0d5708aa8..8b6a3a84b4e 100644
--- a/libswscale/swscale.c
+++ b/libswscale/swscale.c
@@ -224,7 +224,7 @@  static void lumRangeFromJpeg16_c(int16_t *_dst, int width)
     int i;
     int32_t *dst = (int32_t *) _dst;
     for (i = 0; i < width; i++)
-        dst[i] = (dst[i]*(14071/4) + (33561947<<4)/4)>>12;
+        dst[i] = ((int)(dst[i]*(14071U/4) + (33561947<<4)/4)) >> 12;
 }