[FFmpeg-devel] [PATCH 4/4] avcodec/apedec: Fix integer overflow in filter_3800()

Michael Niedermayer michael at niedermayer.cc
Mon Oct 21 02:20:59 EEST 2019


Fixes: signed integer overflow: 2117181180 + 60483298 cannot be represented in type 'int'
Fixes: 18344/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_APE_fuzzer-5685327791915008

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavcodec/apedec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/apedec.c b/libavcodec/apedec.c
index 75c6a96437..72d72f9346 100644
--- a/libavcodec/apedec.c
+++ b/libavcodec/apedec.c
@@ -885,7 +885,7 @@ static av_always_inline int filter_3800(APEPredictor *p,
     p->coeffsB[filter][1] -= (((d4 >> 30) & 2) - 1) * sign;
 
     p->filterB[filter] = p->lastA[filter] + (predictionB >> shift);
-    p->filterA[filter] = p->filterB[filter] + ((int)(p->filterA[filter] * 31U) >> 5);
+    p->filterA[filter] = p->filterB[filter] + (unsigned)((int)(p->filterA[filter] * 31U) >> 5);
 
     return p->filterA[filter];
 }
-- 
2.23.0



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