From 02346292a334a51f6da802146b782bdb01ae9b4e Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Fri, 26 Jul 2019 17:07:01 +0200 Subject: avcodec/alsdec: fix mantisse shift Fixes: shift exponent -1 is negative Fixes: 16039/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ALS_fuzzer-5656825657032704 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/alsdec.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'libavcodec/alsdec.c') diff --git a/libavcodec/alsdec.c b/libavcodec/alsdec.c index d4451482a4..e1449a72a5 100644 --- a/libavcodec/alsdec.c +++ b/libavcodec/alsdec.c @@ -1404,7 +1404,11 @@ static SoftFloat_IEEE754 multiply(SoftFloat_IEEE754 a, SoftFloat_IEEE754 b) { } } - mantissa = (unsigned int)(mantissa_temp >> cutoff_bit_count); + if (cutoff_bit_count >= 0) { + mantissa = (unsigned int)(mantissa_temp >> cutoff_bit_count); + } else { + mantissa = (unsigned int)(mantissa_temp <<-cutoff_bit_count); + } // Need one more shift? if (mantissa & 0x01000000ul) { -- cgit v1.2.3