[FFmpeg-cvslog] avcodec/hevc_ps: Check log2_sao_offset_scale_*

[Michael Niedermayer]

ffmpeg | branch: release/3.4 | Michael Niedermayer <michael at niedermayer.cc> | Wed Jan 24 03:15:23 2018 +0100| [93437a18d878f3924199a3dba5082aa3d09a3094] | committer: Michael Niedermayer

avcodec/hevc_ps: Check log2_sao_offset_scale_*

Fixes: 4868/clusterfuzz-testcase-minimized-6236542906400768
Fixes: runtime error: shift exponent 126 is too large for 32-bit type 'int'

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 4a75a75c62efc645ec28444e4675c325b8f2bb1a)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=93437a18d878f3924199a3dba5082aa3d09a3094
---

 libavcodec/hevc_ps.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/libavcodec/hevc_ps.c b/libavcodec/hevc_ps.c
index 902917d4dd..2ab4c34013 100644
--- a/libavcodec/hevc_ps.c
+++ b/libavcodec/hevc_ps.c
@@ -1324,6 +1324,11 @@ static int pps_range_extensions(GetBitContext *gb, AVCodecContext *avctx,
     pps->log2_sao_offset_scale_luma = get_ue_golomb_long(gb);
     pps->log2_sao_offset_scale_chroma = get_ue_golomb_long(gb);
 
+    if (   pps->log2_sao_offset_scale_luma   > FFMAX(sps->bit_depth        - 10, 0)
+        || pps->log2_sao_offset_scale_chroma > FFMAX(sps->bit_depth_chroma - 10, 0)
+    )
+        return AVERROR_INVALIDDATA;
+
     return(0);
 }