| Message ID | 20210423175056.24019-1-michael@niedermayer.cc |
|---|---|
| State | New |
| Headers | show |
| Series | [FFmpeg-devel,1/7] avformat/asfdec_o: shrink extradata to the initialized size | expand |
| Context | Check | Description |
|---|---|---|
| andriy/x86_make | success | Make finished |
| andriy/x86_make_fate | success | Make fate finished |
| andriy/PPC64_make | success | Make finished |
| andriy/PPC64_make_fate | success | Make fate finished |
On 4/23/2021 2:50 PM, Michael Niedermayer wrote: > Fixes: OOM > Fixes: 27240/clusterfuzz-testcase-minimized-ffmpeg_dem_ASF_O_fuzzer-5937469859823616 > > Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg > Signed-off-by: Michael Niedermayer <michael@niedermayer.cc> > --- > libavformat/asfdec_o.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/libavformat/asfdec_o.c b/libavformat/asfdec_o.c > index 6cfcd8b088..d08a09c14d 100644 > --- a/libavformat/asfdec_o.c > +++ b/libavformat/asfdec_o.c > @@ -600,8 +600,12 @@ static int parse_video_info(AVIOContext *pb, AVStream *st) > memset(st->codecpar->extradata + st->codecpar->extradata_size , 0, > AV_INPUT_BUFFER_PADDING_SIZE); > if ((ret = avio_read(pb, st->codecpar->extradata, > - st->codecpar->extradata_size)) < 0) > + st->codecpar->extradata_size)) < 0) { > + st->codecpar->extradata_size = 0; > + av_freep(&st->codecpar->extradata); > return ret; > + } > + st->codecpar->extradata_size = ret; Use ff_get_extradata() instead. It will simplify the code considerably and get the same result. > } > return 0; > } >
On Fri, Apr 23, 2021 at 08:00:16PM +0200, Andreas Rheinhardt wrote: > Michael Niedermayer: > > Fixes: OOM > > Fixes: 27240/clusterfuzz-testcase-minimized-ffmpeg_dem_ASF_O_fuzzer-5937469859823616 > > > > Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg > > Signed-off-by: Michael Niedermayer <michael@niedermayer.cc> > > --- > > libavformat/asfdec_o.c | 6 +++++- > > 1 file changed, 5 insertions(+), 1 deletion(-) > > > > diff --git a/libavformat/asfdec_o.c b/libavformat/asfdec_o.c > > index 6cfcd8b088..d08a09c14d 100644 > > --- a/libavformat/asfdec_o.c > > +++ b/libavformat/asfdec_o.c > > @@ -600,8 +600,12 @@ static int parse_video_info(AVIOContext *pb, AVStream *st) > > memset(st->codecpar->extradata + st->codecpar->extradata_size , 0, > > AV_INPUT_BUFFER_PADDING_SIZE); > > if ((ret = avio_read(pb, st->codecpar->extradata, > > - st->codecpar->extradata_size)) < 0) > > + st->codecpar->extradata_size)) < 0) { > > + st->codecpar->extradata_size = 0; > > + av_freep(&st->codecpar->extradata); > > return ret; > > + } > > + st->codecpar->extradata_size = ret; > > } > > return 0; > > } > > > How important is it to preserve partially read extradata? If it is not > important, one could just use ff_get_extradata(); if it is important, > then memset should be performed after the read, so that the real padding > of the extradata is zeroed (it is uninitialized with your patch if the > desired size could not be read). i guess its not important to preserve, will apply with ff_get_extradata() thanks [...]
diff --git a/libavformat/asfdec_o.c b/libavformat/asfdec_o.c index 6cfcd8b088..d08a09c14d 100644 --- a/libavformat/asfdec_o.c +++ b/libavformat/asfdec_o.c @@ -600,8 +600,12 @@ static int parse_video_info(AVIOContext *pb, AVStream *st) memset(st->codecpar->extradata + st->codecpar->extradata_size , 0, AV_INPUT_BUFFER_PADDING_SIZE); if ((ret = avio_read(pb, st->codecpar->extradata, - st->codecpar->extradata_size)) < 0) + st->codecpar->extradata_size)) < 0) { + st->codecpar->extradata_size = 0; + av_freep(&st->codecpar->extradata); return ret; + } + st->codecpar->extradata_size = ret; } return 0; }
Fixes: OOM Fixes: 27240/clusterfuzz-testcase-minimized-ffmpeg_dem_ASF_O_fuzzer-5937469859823616 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer <michael@niedermayer.cc> --- libavformat/asfdec_o.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)