[FFmpeg-devel] [PATCH 2/5] avcodec/alsdec: fix undefined shift in multiply()
Michael Niedermayer
michael at niedermayer.cc
Sun Jul 7 16:18:11 EEST 2019
Fixes: left shift of negative value -6
Fixes: 15564/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ALS_fuzzer-5701655938465792
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/alsdec.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/libavcodec/alsdec.c b/libavcodec/alsdec.c
index 8201deb366..6b5774175b 100644
--- a/libavcodec/alsdec.c
+++ b/libavcodec/alsdec.c
@@ -1416,7 +1416,7 @@ static SoftFloat_IEEE754 multiply(SoftFloat_IEEE754 a, SoftFloat_IEEE754 b) {
return_val = 0x80000000U;
}
- return_val |= (a.exp + b.exp + bit_count - 47) << 23;
+ return_val |= ((unsigned)av_clip(a.exp + b.exp + bit_count - 47, -126, 127) << 23) & 0x7F800000;
return_val |= mantissa;
return av_bits2sf_ieee754(return_val);
}
--
2.22.0
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