[FFmpeg-cvslog] avcodec/aacdec_fixed: Fix multiple runtime error: shift exponent 127 is too large for 32-bit type 'int'

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Tue May 23 12:40:22 2017 +0200| [620b452a118a6a2345addb4e1d8abf36ad8d1bab] | committer: Michael Niedermayer

avcodec/aacdec_fixed: Fix multiple runtime error: shift exponent 127 is too large for 32-bit type 'int'

Fixes: 1762/clusterfuzz-testcase-minimized-5150981081792512

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

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=620b452a118a6a2345addb4e1d8abf36ad8d1bab
---

 libavcodec/aacdec_fixed.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/libavcodec/aacdec_fixed.c b/libavcodec/aacdec_fixed.c
index 7b5e40e484..27547667ab 100644
--- a/libavcodec/aacdec_fixed.c
+++ b/libavcodec/aacdec_fixed.c
@@ -415,7 +415,9 @@ static void apply_independent_coupling_fixed(AACContext *ac,
 
     c = cce_scale_fixed[gain & 7];
     shift = (gain-1024) >> 3;
-    if (shift < 0) {
+    if (shift < -31) {
+        return;
+    } else if (shift < 0) {
         shift = -shift;
         round = 1 << (shift - 1);