ffmpeg | branch: release/2.2 | Vittorio Giovara <vittorio.giov...@gmail.com> | Wed Jul 30 19:33:36 2014 +0100| [2273e5ed992661e0c4b37208e792e2253d5a0b5b] | committer: Vittorio Giovara
h264: prevent theoretical infinite loop in SEI parsing Properly address CVE-2011-3946 and parse bitstream as described in the spec. CC: libav-sta...@libav.org Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=2273e5ed992661e0c4b37208e792e2253d5a0b5b --- libavcodec/h264_sei.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/libavcodec/h264_sei.c b/libavcodec/h264_sei.c index 6fca2c3..1e5a134 100644 --- a/libavcodec/h264_sei.c +++ b/libavcodec/h264_sei.c @@ -205,14 +205,20 @@ int ff_h264_decode_sei(H264Context *h) int size = 0; int type = 0; int ret = 0; + int last = 0; - do - type += show_bits(&h->gb, 8); - while (get_bits(&h->gb, 8) == 255); + while (get_bits_left(&h->gb) >= 8 && + (last = get_bits(&h->gb, 8)) == 255) { + type += 255; + } + type += last; - do - size += show_bits(&h->gb, 8); - while (get_bits(&h->gb, 8) == 255); + last = 0; + while (get_bits_left(&h->gb) >= 8 && + (last = get_bits(&h->gb, 8)) == 255) { + size += 255; + } + size += last; if (size > get_bits_left(&h->gb) / 8) { av_log(h->avctx, AV_LOG_ERROR, "SEI type %d truncated at %d\n", _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog
