From f458d65bb42b8709d2bb169413744786d55781b0 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Fri, 3 Mar 2017 04:39:05 +0100 Subject: [PATCH] avcodec/mpeg12dec: Fix runtime error: left shift of negative value -13 Fixes: 709/clusterfuzz-testcase-4789836449841152 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg Signed-off-by: Michael Niedermayer (cherry picked from commit d757ddbaab8f03b3664788e620314b70ac791319) Signed-off-by: Michael Niedermayer --- libavcodec/mpeg12dec.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/libavcodec/mpeg12dec.c b/libavcodec/mpeg12dec.c index 6e378edf57..4f520819e0 100644 --- a/libavcodec/mpeg12dec.c +++ b/libavcodec/mpeg12dec.c @@ -563,7 +563,7 @@ static inline int mpeg2_decode_block_intra(MpegEncContext *s, dc = s->last_dc[component]; dc += diff; s->last_dc[component] = dc; - block[0] = dc << (3 - s->intra_dc_precision); + block[0] = dc * (1 << (3 - s->intra_dc_precision)); ff_tlog(s->avctx, "dc=%d\n", block[0]); mismatch = block[0] ^ 1; i = 0;