From 1b7d02642b2096622cee6165fea1301bb9ad54ff Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sat, 2 Nov 2019 15:52:52 +0100 Subject: [PATCH] avcodec/ralf: use multiply instead of shift to avoid undefined behavior in decode_block() Fixes: left shift of negative value -249 Fixes: 18566/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_RALF_fuzzer-5649394561187840 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/ralf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/libavcodec/ralf.c b/libavcodec/ralf.c index 1d881cf7ae3..ca8817aa21e 100644 --- a/libavcodec/ralf.c +++ b/libavcodec/ralf.c @@ -408,7 +408,7 @@ static int decode_block(AVCodecContext *avctx, GetBitContext *gb, case 4: for (i = 0; i < len; i++) { t = ch1[i] + ctx->bias[1]; - t2 = ((ch0[i] + ctx->bias[0]) << 1) | (t & 1); + t2 = ((ch0[i] + ctx->bias[0]) * 2) | (t & 1); dst0[i] = (t2 + t) / 2; dst1[i] = (t2 - t) / 2; } -- 2.39.5