From cd74af14162c803f18e90bb12b52135e893d990c Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Thu, 7 May 2020 12:38:26 +0200 Subject: avformat/mpegts: Shuffle avio_seek This avoids accessing an old, no longer valid buffer. Fixes: out of array access Fixes: crash_audio-2020 Found-by: le wu Reviewed-by: Marton Balint Signed-off-by: Michael Niedermayer --- libavformat/mpegts.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'libavformat') diff --git a/libavformat/mpegts.c b/libavformat/mpegts.c index 0833d62ea5..a065c61c40 100644 --- a/libavformat/mpegts.c +++ b/libavformat/mpegts.c @@ -2881,15 +2881,16 @@ static int mpegts_resync(AVFormatContext *s, int seekback, const uint8_t *curren AVIOContext *pb = s->pb; int c, i; uint64_t pos = avio_tell(pb); - - avio_seek(pb, -FFMIN(seekback, pos), SEEK_CUR); + int64_t back = FFMIN(seekback, pos); //Special case for files like 01c56b0dc1.ts if (current_packet[0] == 0x80 && current_packet[12] == 0x47) { - avio_seek(pb, 12, SEEK_CUR); + avio_seek(pb, 12 - back, SEEK_CUR); return 0; } + avio_seek(pb, -back, SEEK_CUR); + for (i = 0; i < ts->resync_size; i++) { c = avio_r8(pb); if (avio_feof(pb)) -- cgit v1.2.3