highperfocused/ffmpeg
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

avcodec/h263dec: Avoid parsing extradata repeatedly

Browse Source 
Fixes: Timeout
Fixes: 52329/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MPEG4_fuzzer-4716563886637056

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2022-11-18 00:07:05 +01:00
parent ff2d1bbe73
commit b32316923d
No known key found for this signature in database
GPG Key ID: B18E8928B3948D64
2 changed files with 3 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
libavcodec/h263dec.c
View File

@ -492,11 +492,12 @@ retry:
} else if (CONFIG_MSMPEG4DEC && s->msmpeg4_version) {
ret = ff_msmpeg4_decode_picture_header(s);
} else if (CONFIG_MPEG4_DECODER && avctx->codec_id == AV_CODEC_ID_MPEG4) {
if (s->avctx->extradata_size && s->picture_number == 0) {
if (s->avctx->extradata_size && !s->extradata_parsed) {
GetBitContext gb;
if (init_get_bits8(&gb, s->avctx->extradata, s->avctx->extradata_size) >= 0 )
ff_mpeg4_decode_picture_header(avctx->priv_data, &gb, 1, 0);
s->extradata_parsed = 1;
}
ret = ff_mpeg4_decode_picture_header(avctx->priv_data, &s->gb, 0, 0);
} else if (CONFIG_H263I_DECODER && s->codec_id == AV_CODEC_ID_H263I) {

1
libavcodec/mpegvideo.h
View File

@ -117,6 +117,7 @@ typedef struct MpegEncContext {
int input_picture_number; ///< used to set pic->display_picture_number, should not be used for/by anything else
int coded_picture_number; ///< used to set pic->coded_picture_number, should not be used for/by anything else
int picture_number; //FIXME remove, unclear definition
int extradata_parsed;
int picture_in_gop_number; ///< 0-> first pic in gop, ...
int mb_width, mb_height; ///< number of MBs horizontally & vertically
int mb_stride; ///< mb_width+1 used for some arrays to allow simple addressing of left & top MBs without sig11