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[FFmpeg-devel,4/4] avcodec/photocd: Use ff_set_dimensions()

Message ID 20200920202608.11653-4-michael@niedermayer.cc
State Accepted
Commit 34df97b0886c728e1ae430a7de8b3dfd2f1a5744
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Series [FFmpeg-devel,1/4] avformat/wvdec: Check rate for overflow
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Commit Message

Michael Niedermayer Sept. 20, 2020, 8:26 p.m. UTC
Fixes: out of memory
Fixes: 25588/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_PHOTOCD_fuzzer-6612945080156160

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavcodec/photocd.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Comments

Paul B Mahol Sept. 20, 2020, 10:28 p.m. UTC | #1
On Sun, Sep 20, 2020 at 10:26:08PM +0200, Michael Niedermayer wrote:
> Fixes: out of memory
> Fixes: 25588/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_PHOTOCD_fuzzer-6612945080156160
> 
> Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
> ---
>  libavcodec/photocd.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/libavcodec/photocd.c b/libavcodec/photocd.c
> index 057c9d33d4..07f10e28b7 100644
> --- a/libavcodec/photocd.c
> +++ b/libavcodec/photocd.c
> @@ -324,8 +324,9 @@ static int photocd_decode_frame(AVCodecContext *avctx, void *data,
>      else
>          s->resolution = av_clip(4 - s->lowres, 0, 4);
>  
> -    avctx->width  = img_info[s->resolution].width;
> -    avctx->height = img_info[s->resolution].height;
> +    ret = ff_set_dimensions(avctx, img_info[s->resolution].width, img_info[s->resolution].height);
> +    if (ret < 0)
> +        return ret;
>  
>      if ((ret = ff_thread_get_buffer(avctx, &frame, 0)) < 0)
>          return ret;

Why is this needed at all, dimensions are alway static and completely allocable.
Michael Niedermayer Oct. 10, 2020, 11 a.m. UTC | #2
On Mon, Sep 21, 2020 at 12:28:37AM +0200, Paul B Mahol wrote:
> On Sun, Sep 20, 2020 at 10:26:08PM +0200, Michael Niedermayer wrote:
> > Fixes: out of memory
> > Fixes: 25588/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_PHOTOCD_fuzzer-6612945080156160
> > 
> > Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> > Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
> > ---
> >  libavcodec/photocd.c | 5 +++--
> >  1 file changed, 3 insertions(+), 2 deletions(-)
> > 
> > diff --git a/libavcodec/photocd.c b/libavcodec/photocd.c
> > index 057c9d33d4..07f10e28b7 100644
> > --- a/libavcodec/photocd.c
> > +++ b/libavcodec/photocd.c
> > @@ -324,8 +324,9 @@ static int photocd_decode_frame(AVCodecContext *avctx, void *data,
> >      else
> >          s->resolution = av_clip(4 - s->lowres, 0, 4);
> >  
> > -    avctx->width  = img_info[s->resolution].width;
> > -    avctx->height = img_info[s->resolution].height;
> > +    ret = ff_set_dimensions(avctx, img_info[s->resolution].width, img_info[s->resolution].height);
> > +    if (ret < 0)
> > +        return ret;
> >  
> >      if ((ret = ff_thread_get_buffer(avctx, &frame, 0)) < 0)
> >          return ret;
> 
> Why is this needed at all, dimensions are alway static and completely allocable.

ff_set_dimensions() sets more than width and height, for example 
it also sets coded_width and coded_height. And it checks dimension validity and
compliance to the users requirements.
There are multiple things here the previous code failed to do and which could
cause problems.

I would suggest to simply always use ff_set_dimensions().

Thanks


[...]
Michael Niedermayer Oct. 18, 2020, 6:33 p.m. UTC | #3
On Sat, Oct 10, 2020 at 01:00:14PM +0200, Michael Niedermayer wrote:
> On Mon, Sep 21, 2020 at 12:28:37AM +0200, Paul B Mahol wrote:
> > On Sun, Sep 20, 2020 at 10:26:08PM +0200, Michael Niedermayer wrote:
> > > Fixes: out of memory
> > > Fixes: 25588/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_PHOTOCD_fuzzer-6612945080156160
> > > 
> > > Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> > > Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
> > > ---
> > >  libavcodec/photocd.c | 5 +++--
> > >  1 file changed, 3 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/libavcodec/photocd.c b/libavcodec/photocd.c
> > > index 057c9d33d4..07f10e28b7 100644
> > > --- a/libavcodec/photocd.c
> > > +++ b/libavcodec/photocd.c
> > > @@ -324,8 +324,9 @@ static int photocd_decode_frame(AVCodecContext *avctx, void *data,
> > >      else
> > >          s->resolution = av_clip(4 - s->lowres, 0, 4);
> > >  
> > > -    avctx->width  = img_info[s->resolution].width;
> > > -    avctx->height = img_info[s->resolution].height;
> > > +    ret = ff_set_dimensions(avctx, img_info[s->resolution].width, img_info[s->resolution].height);
> > > +    if (ret < 0)
> > > +        return ret;
> > >  
> > >      if ((ret = ff_thread_get_buffer(avctx, &frame, 0)) < 0)
> > >          return ret;
> > 
> > Why is this needed at all, dimensions are alway static and completely allocable.
> 
> ff_set_dimensions() sets more than width and height, for example 
> it also sets coded_width and coded_height. And it checks dimension validity and
> compliance to the users requirements.
> There are multiple things here the previous code failed to do and which could
> cause problems.
> 
> I would suggest to simply always use ff_set_dimensions().

will apply patch


[...]
diff mbox series

Patch

diff --git a/libavcodec/photocd.c b/libavcodec/photocd.c
index 057c9d33d4..07f10e28b7 100644
--- a/libavcodec/photocd.c
+++ b/libavcodec/photocd.c
@@ -324,8 +324,9 @@  static int photocd_decode_frame(AVCodecContext *avctx, void *data,
     else
         s->resolution = av_clip(4 - s->lowres, 0, 4);
 
-    avctx->width  = img_info[s->resolution].width;
-    avctx->height = img_info[s->resolution].height;
+    ret = ff_set_dimensions(avctx, img_info[s->resolution].width, img_info[s->resolution].height);
+    if (ret < 0)
+        return ret;
 
     if ((ret = ff_thread_get_buffer(avctx, &frame, 0)) < 0)
         return ret;