From cd9b0bb07a66d3299bd62922e9dfa742219abe79 Mon Sep 17 00:00:00 2001 From: Luca Barbato Date: Fri, 7 Jun 2013 16:16:46 +0200 Subject: [PATCH] 4xm: validate the buffer size before parsing it Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind CC: libav-stable@libav.org (cherry picked from commit de2e5777e225e75813daf2373c95e223651fd89a) Signed-off-by: Luca Barbato --- libavcodec/4xm.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) diff --git a/libavcodec/4xm.c b/libavcodec/4xm.c index 77d15d5803..52c16cfd77 100644 --- a/libavcodec/4xm.c +++ b/libavcodec/4xm.c @@ -382,6 +382,8 @@ static int decode_p_frame(FourXContext *f, const uint8_t *buf, int length){ unsigned int bitstream_size, bytestream_size, wordstream_size, extra, bytestream_offset, wordstream_offset; if(f->version>1){ + if (length < 20) + return AVERROR_INVALIDDATA; extra=20; bitstream_size= AV_RL32(buf+8); wordstream_size= AV_RL32(buf+12); @@ -734,18 +736,28 @@ static int decode_frame(AVCodecContext *avctx, AVFrame *p, temp; int i, frame_4cc, frame_size; - frame_4cc= AV_RL32(buf); - if(buf_size != AV_RL32(buf+4)+8 || buf_size < 20){ - av_log(f->avctx, AV_LOG_ERROR, "size mismatch %d %d\n", buf_size, AV_RL32(buf+4)); + if (buf_size < 20) + return AVERROR_INVALIDDATA; + + if (buf_size < AV_RL32(buf + 4) + 8) { + av_log(f->avctx, AV_LOG_ERROR, + "size mismatch %d %d\n", buf_size, AV_RL32(buf + 4)); } + frame_4cc = AV_RL32(buf); + if(frame_4cc == AV_RL32("cfrm")){ int free_index=-1; - const int data_size= buf_size - 20; - const int id= AV_RL32(buf+12); - const int whole_size= AV_RL32(buf+16); + int id, whole_size; + const int data_size = buf_size - 20; CFrameBuffer *cfrm; + if (data_size < 0) + return AVERROR_INVALIDDATA; + + id = AV_RL32(buf + 12); + whole_size = AV_RL32(buf + 16); + for(i=0; icfrm[i].id && f->cfrm[i].id < avctx->frame_number) av_log(f->avctx, AV_LOG_ERROR, "lost c frame %d\n", f->cfrm[i].id);