[FFmpeg-cvslog] avcodec/snowdec: Fix integer overflow in header parsing
Michael Niedermayer
git at videolan.org
Sat Dec 2 01:49:35 EET 2017
ffmpeg | branch: release/3.0 | Michael Niedermayer <michael at niedermayer.cc> | Sun Nov 5 21:20:05 2017 +0100| [f33f13172cfe34b3bedb59964957d8d784f9cea0] | committer: Michael Niedermayer
avcodec/snowdec: Fix integer overflow in header parsing
Fixes: 3984/clusterfuzz-testcase-minimized-5265759929368576
Fixes: runtime error: signed integer overflow: -1085585801 + -1094995529 cannot be represented in 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 c897a9285846b6a072b9650976afd4f091b7a71f)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=f33f13172cfe34b3bedb59964957d8d784f9cea0
---
libavcodec/snowdec.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/libavcodec/snowdec.c b/libavcodec/snowdec.c
index 6eff729a19..2b92ed3de0 100644
--- a/libavcodec/snowdec.c
+++ b/libavcodec/snowdec.c
@@ -374,7 +374,7 @@ static int decode_header(SnowContext *s){
}
}
- s->spatial_decomposition_type+= get_symbol(&s->c, s->header_state, 1);
+ s->spatial_decomposition_type+= (unsigned)get_symbol(&s->c, s->header_state, 1);
if(s->spatial_decomposition_type > 1U){
av_log(s->avctx, AV_LOG_ERROR, "spatial_decomposition_type %d not supported\n", s->spatial_decomposition_type);
return AVERROR_INVALIDDATA;
@@ -390,10 +390,10 @@ static int decode_header(SnowContext *s){
}
- s->qlog += get_symbol(&s->c, s->header_state, 1);
- s->mv_scale += get_symbol(&s->c, s->header_state, 1);
- s->qbias += get_symbol(&s->c, s->header_state, 1);
- s->block_max_depth+= get_symbol(&s->c, s->header_state, 1);
+ s->qlog += (unsigned)get_symbol(&s->c, s->header_state, 1);
+ s->mv_scale += (unsigned)get_symbol(&s->c, s->header_state, 1);
+ s->qbias += (unsigned)get_symbol(&s->c, s->header_state, 1);
+ s->block_max_depth+= (unsigned)get_symbol(&s->c, s->header_state, 1);
if(s->block_max_depth > 1 || s->block_max_depth < 0 || s->mv_scale > 256U){
av_log(s->avctx, AV_LOG_ERROR, "block_max_depth= %d is too large\n", s->block_max_depth);
s->block_max_depth= 0;
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