From dad9a86ca7bf912289aafb33d96980630e6ec53a Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Mon, 26 Oct 2020 21:08:55 +0100 Subject: [PATCH] avformat/gxf: Check pkt_len Fixes: Infinite loop Fixes: 26576/clusterfuzz-testcase-minimized-ffmpeg_dem_GXF_fuzzer-4823080360476672 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavformat/gxf.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/libavformat/gxf.c b/libavformat/gxf.c index 96b7035386..b787d4f521 100644 --- a/libavformat/gxf.c +++ b/libavformat/gxf.c @@ -285,9 +285,12 @@ static void gxf_track_tags(AVIOContext *pb, int *len, struct gxf_stream_info *si static void gxf_read_index(AVFormatContext *s, int pkt_len) { AVIOContext *pb = s->pb; AVStream *st; - uint32_t fields_per_map = avio_rl32(pb); - uint32_t map_cnt = avio_rl32(pb); + uint32_t fields_per_map, map_cnt; int i; + if (pkt_len < 8) + return; + fields_per_map = avio_rl32(pb); + map_cnt = avio_rl32(pb); pkt_len -= 8; if ((s->flags & AVFMT_FLAG_IGNIDX) || !s->streams) { avio_skip(pb, pkt_len);