From 55f9683cf6be97f4b398a7a35ee5bfd1208ac2a5 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Mon, 3 Feb 2020 23:20:23 +0100 Subject: [PATCH] avcodec/flac_parser: Do not lose header count in find_headers_search() Fixes: Timeout Fixes: out of array access Fixes: 20274/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_FLAC_fuzzer-5649631988154368 Fixes: 19275/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_FLAC_fuzzer-5757535722405888 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/flac_parser.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/libavcodec/flac_parser.c b/libavcodec/flac_parser.c index 9ffa288548..3424583c49 100644 --- a/libavcodec/flac_parser.c +++ b/libavcodec/flac_parser.c @@ -208,16 +208,20 @@ static int find_headers_search(FLACParseContext *fpc, uint8_t *buf, uint32_t x; for (i = 0; i < mod_offset; i++) { - if ((AV_RB16(buf + i) & 0xFFFE) == 0xFFF8) - size = find_headers_search_validate(fpc, search_start + i); + if ((AV_RB16(buf + i) & 0xFFFE) == 0xFFF8) { + int ret = find_headers_search_validate(fpc, search_start + i); + size = FFMAX(size, ret); + } } for (; i < buf_size - 1; i += 4) { x = AV_RN32(buf + i); if (((x & ~(x + 0x01010101)) & 0x80808080)) { for (j = 0; j < 4; j++) { - if ((AV_RB16(buf + i + j) & 0xFFFE) == 0xFFF8) - size = find_headers_search_validate(fpc, search_start + i + j); + if ((AV_RB16(buf + i + j) & 0xFFFE) == 0xFFF8) { + int ret = find_headers_search_validate(fpc, search_start + i + j); + size = FFMAX(size, ret); + } } } }