[FFmpeg-devel] [PATCH] avcodec/dirac_vlc: Fix integer overflow in ff_dirac_golomb_read_32bit()

Michael Niedermayer michael at niedermayer.cc
Sat Apr 25 01:04:31 EEST 2020


Fixes: left shift of 1073741824 by 1 places cannot be represented in type 'int32_t' (aka 'int')
Fixes: 21245/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_DIRAC_fuzzer-5683334274613248

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

diff --git a/libavcodec/dirac_vlc.c b/libavcodec/dirac_vlc.c
index fbe28017bc..6d53078fc0 100644
--- a/libavcodec/dirac_vlc.c
+++ b/libavcodec/dirac_vlc.c
@@ -1115,7 +1115,7 @@ int ff_dirac_golomb_read_32bit(const uint8_t *buf, int bytes,
 {
     LUTState lut = ff_dirac_golomb_lut[*buf++];
     int32_t *dst = (int32_t *)_dst, *last = dst + coeffs;
-    int32_t val = 0;
+    uint32_t val = 0;
 
     for (int i = 1; i < bytes; i++)
         PROCESS_VALS;
-- 
2.17.1



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