From 85b883429fb1a8c1be2e39fee510315a92b6cd02 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Tue, 4 May 2021 18:22:40 +0200 Subject: [PATCH] avutil/tx: avoid negative left shifts Fixes: left shift of negative value -1 Fixes: 33736/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_SIREN_fuzzer-6657785795313664 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavutil/tx.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/libavutil/tx.c b/libavutil/tx.c index 8da04e99ca..25adb6b37e 100644 --- a/libavutil/tx.c +++ b/libavutil/tx.c @@ -97,9 +97,9 @@ static inline int split_radix_permutation(int i, int m, int inverse) if (m <= 1) return i & 1; if (!(i & m)) - return (split_radix_permutation(i, m, inverse) << 1); + return split_radix_permutation(i, m, inverse) * 2; m >>= 1; - return (split_radix_permutation(i, m, inverse) << 2) + 1 - 2*(!(i & m) ^ inverse); + return split_radix_permutation(i, m, inverse) * 4 + 1 - 2*(!(i & m) ^ inverse); } int ff_tx_gen_ptwo_revtab(AVTXContext *s, int invert_lookup)