From 55d4e22d71ca75223ee61f7d2535fdc6e9991026 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sat, 31 Aug 2019 23:20:01 +0200 Subject: [PATCH] avformat/vividas: check for tiny blocks using alignment Ask for a sample for these Fixes: out of array access Fixes: 16624/clusterfuzz-testcase-minimized-ffmpeg_DEMUXER_fuzzer-5762455661182976 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavformat/vividas.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/libavformat/vividas.c b/libavformat/vividas.c index 645e322b6e..1ac86a107e 100644 --- a/libavformat/vividas.c +++ b/libavformat/vividas.c @@ -153,6 +153,10 @@ static void decode_block(uint8_t *src, uint8_t *dest, unsigned size, if (align) { uint32_t tmpkey = *key_ptr - key; + if (a2 > s) { + a2 = s; + avpriv_request_sample(NULL, "tiny aligned block\n"); + } memcpy(tmp + align, src, a2); xor_block(tmp, tmp, 4, key, &tmpkey); memcpy(dest, tmp + align, a2); -- GitLab