From bd0f81526d3f4c23ecd0a399829103be2445c011 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sat, 13 Jun 2020 11:21:52 +0200 Subject: [PATCH] avcodec/pixlet: Fix log(0) check Fixes: passing zero to clz(), which is not a valid argument Fixes: 23337/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_PIXLET_fuzzer-5179131989065728 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/pixlet.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/libavcodec/pixlet.c b/libavcodec/pixlet.c index 7b068b1ce5..78f571cd5f 100644 --- a/libavcodec/pixlet.c +++ b/libavcodec/pixlet.c @@ -221,7 +221,7 @@ static int read_high_coeffs(AVCodecContext *avctx, uint8_t *src, int16_t *dst, length = 25 - nbits; while (i < size) { - if (state >> 8 != -3) + if (((state >> 8) + 3) & 0xFFFFFFF) value = ff_clz((state >> 8) + 3) ^ 0x1F; else value = -1; -- GitLab