From 2749e20d044c5b014b1cb2749d97078df3a88ba1 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Tue, 8 Sep 2020 23:03:19 +0200 Subject: [PATCH] avcodec/fastaudio: Fix invalid shift exponent 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 --- libavcodec/fastaudio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/libavcodec/fastaudio.c b/libavcodec/fastaudio.c index 1dda310612..e50678cd3d 100644 --- a/libavcodec/fastaudio.c +++ b/libavcodec/fastaudio.c @@ -89,7 +89,7 @@ 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);