From 0eecf40935b22644e6cd74c586057237ecfd6844 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Tue, 25 Nov 2014 13:53:06 +0100 Subject: avcodec/mjpegdec: Fix context fields becoming inconsistent Fixes out of array access Fixes: asan_heap-oob_1ca4f85_2760_cov_144449187_miss_congeniality_pegasus_ljpg.avi Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind Signed-off-by: Michael Niedermayer --- libavcodec/mjpegdec.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) (limited to 'libavcodec') diff --git a/libavcodec/mjpegdec.c b/libavcodec/mjpegdec.c index a9569a80f6..f2c81e6a42 100644 --- a/libavcodec/mjpegdec.c +++ b/libavcodec/mjpegdec.c @@ -1620,6 +1620,8 @@ static int mjpeg_decode_app(MJpegDecodeContext *s) } if (id == AV_RB32("LJIF")) { + int rgb = s->rgb; + int pegasus_rct = s->pegasus_rct; if (s->avctx->debug & FF_DEBUG_PICT_INFO) av_log(s->avctx, AV_LOG_INFO, "Pegasus lossless jpeg header found\n"); @@ -1629,17 +1631,27 @@ static int mjpeg_decode_app(MJpegDecodeContext *s) skip_bits(&s->gb, 16); /* unknown always 0? */ switch (i=get_bits(&s->gb, 8)) { case 1: - s->rgb = 1; - s->pegasus_rct = 0; + rgb = 1; + pegasus_rct = 0; break; case 2: - s->rgb = 1; - s->pegasus_rct = 1; + rgb = 1; + pegasus_rct = 1; break; default: av_log(s->avctx, AV_LOG_ERROR, "unknown colorspace %d\n", i); } + len -= 9; + if (s->got_picture) + if (rgb != s->rgb || pegasus_rct != s->pegasus_rct) { + av_log(s->avctx, AV_LOG_WARNING, "Mismatching LJIF tag\n"); + goto out; + } + + s->rgb = rgb; + s->pegasus_rct = pegasus_rct; + goto out; } if (id == AV_RL32("colr") && len > 0) { -- cgit v1.2.3