[FFmpeg-cvslog] avutil/common: Fix integer overflow in av_clip_uint8_c() and av_clip_uint16_c()

[Michael Niedermayer]

ffmpeg | branch: release/2.8 | Michael Niedermayer <michael at niedermayer.cc> | Wed Feb 14 03:54:13 2018 +0100| [a3c66132d957db7f146601ac35f31944b0e5d98f] | committer: Michael Niedermayer

avutil/common: Fix integer overflow in av_clip_uint8_c() and av_clip_uint16_c()

Fixes: 5567/clusterfuzz-testcase-minimized-5769966247739392
Fixes: runtime error: negation of -2147483648 cannot be represented in type 'int'; cast to an unsigned type to negate this value to itself

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit ab6f571ef71967da7c7c1cfba483d3597c7357d5)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=a3c66132d957db7f146601ac35f31944b0e5d98f
---

 libavutil/common.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libavutil/common.h b/libavutil/common.h
index 7fe3ccc25a..81f5fedf29 100644
--- a/libavutil/common.h
+++ b/libavutil/common.h
@@ -162,7 +162,7 @@ static av_always_inline av_const int64_t av_clip64_c(int64_t a, int64_t amin, in
  */
 static av_always_inline av_const uint8_t av_clip_uint8_c(int a)
 {
-    if (a&(~0xFF)) return (-a)>>31;
+    if (a&(~0xFF)) return (~a)>>31;
     else           return a;
 }
 
@@ -184,7 +184,7 @@ static av_always_inline av_const int8_t av_clip_int8_c(int a)
  */
 static av_always_inline av_const uint16_t av_clip_uint16_c(int a)
 {
-    if (a&(~0xFFFF)) return (-a)>>31;
+    if (a&(~0xFFFF)) return (~a)>>31;
     else             return a;
 }