[FFmpeg-cvslog] avcodec/exr: fix undefined shift in pxr24_uncompress()

[Michael Niedermayer]

ffmpeg | branch: release/3.2 | Michael Niedermayer <michael at niedermayer.cc> | Sat Nov  4 01:19:19 2017 +0100| [8b8502a66f00a0e2ae186d1edd3eeb2ef1eb6bd3] | committer: Michael Niedermayer

avcodec/exr: fix undefined shift in pxr24_uncompress()

Fixes: runtime error: left shift of 255 by 24 places cannot be represented in type 'int'
Fixes: 3787/clusterfuzz-testcase-minimized-5728764920070144

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Paul B Mahol <onemda at gmail.com>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 66f0c958bfd5475658b432d1af4d2e174b2dfcda)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=8b8502a66f00a0e2ae186d1edd3eeb2ef1eb6bd3
---

 libavcodec/exr.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/exr.c b/libavcodec/exr.c
index 47d30fa804..4b0cf21cdb 100644
--- a/libavcodec/exr.c
+++ b/libavcodec/exr.c
@@ -864,7 +864,7 @@ static int pxr24_uncompress(EXRContext *s, const uint8_t *src,
                 in     = ptr[2] + td->xsize;
 
                 for (j = 0; j < td->xsize; ++j) {
-                    uint32_t diff = (*(ptr[0]++) << 24) |
+                    uint32_t diff = ((unsigned)*(ptr[0]++) << 24) |
                                     (*(ptr[1]++) << 16) |
                                     (*(ptr[2]++) << 8);
                     pixel += diff;