From 7b213e88b5e6d39a2c8a8340c746b70d1019e89c Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sat, 7 Feb 2015 02:06:20 +0100 Subject: [PATCH] avcodec/h264_slice: Do not change frame_num after the first slice Fixes potential race condition Fixes: signal_sigsegv_1472ac3_468_cov_2915641226_CABACI3_Sony_B.jsv Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind Signed-off-by: Michael Niedermayer (cherry picked from commit f906982c9411f3062e3ce68013309b37c213c4dd) Signed-off-by: Michael Niedermayer --- libavcodec/h264_slice.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/libavcodec/h264_slice.c b/libavcodec/h264_slice.c index b1709f9bba..2ed62c9423 100644 --- a/libavcodec/h264_slice.c +++ b/libavcodec/h264_slice.c @@ -1306,6 +1306,7 @@ int ff_h264_decode_slice_header(H264Context *h, H264Context *h0) int needs_reinit = 0; int field_pic_flag, bottom_field_flag; int first_slice = h == h0 && !h0->current_slice; + int frame_num; PPS *pps; h->qpel_put = h->h264qpel.put_h264_qpel_pixels_tab; @@ -1515,7 +1516,15 @@ int ff_h264_decode_slice_header(H264Context *h, H264Context *h0) h264_init_dequant_tables(h); } - h->frame_num = get_bits(&h->gb, h->sps.log2_max_frame_num); + frame_num = get_bits(&h->gb, h->sps.log2_max_frame_num); + if (!first_slice) { + if (h0->frame_num != frame_num) { + av_log(h->avctx, AV_LOG_ERROR, "Frame num change from %d to %d\n", + h0->frame_num, frame_num); + return AVERROR_INVALIDDATA; + } + } + h->frame_num = frame_num; h->mb_mbaff = 0; h->mb_aff_frame = 0;