[FFmpeg-devel] [PATCH 2/4] avutil/common: Fix undefined behavior in av_clip_uintp2_c()

[Michael Niedermayer]

Fixes: negation of -2147483648 cannot be represented in type 'int'; cast to an unsigned type to negate this value to itself
Fixes: 8521/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_DIRAC_fuzzer-5639024952737792

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavutil/common.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavutil/common.h b/libavutil/common.h
index 0fffa67714..8db0291170 100644
--- a/libavutil/common.h
+++ b/libavutil/common.h
@@ -228,7 +228,7 @@ static av_always_inline av_const int av_clip_intp2_c(int a, int p)
  */
 static av_always_inline av_const unsigned av_clip_uintp2_c(int a, int p)
 {
-    if (a & ~((1<<p) - 1)) return -a >> 31 & ((1<<p) - 1);
+    if (a & ~((1<<p) - 1)) return (~a) >> 31 & ((1<<p) - 1);
     else                   return  a;
 }
 
-- 
2.17.1