[FFmpeg-devel] [PATCH 3/3] avcodec/fastaudio: Fix invalid shift exponent
Michael Niedermayer
michael at niedermayer.cc
Wed Sep 9 00:29:21 EEST 2020
Fixes: shift exponent 32 is too large for 32-bit type 'unsigned int'
Fixes: 25434/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_FASTAUDIO_fuzzer-6252363168612352
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/fastaudio.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/libavcodec/fastaudio.c b/libavcodec/fastaudio.c
index 16f44790f5..e37d4f8425 100644
--- a/libavcodec/fastaudio.c
+++ b/libavcodec/fastaudio.c
@@ -92,7 +92,7 @@ static int read_bits(int bits, int *ppos, unsigned *src)
pos = *ppos;
pos += bits;
- r = src[(pos - 1) / 32] >> (32 - pos % 32);
+ r = src[(pos - 1) / 32] >> ((-pos) & 31);
*ppos = pos;
return r & ((1 << bits) - 1);
--
2.17.1
More information about the ffmpeg-devel
mailing list