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[FFmpeg-devel] avformat/ape: Error out in case of EOF in the header

Message ID 20200724230816.23460-1-michael@niedermayer.cc
State Accepted
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Series [FFmpeg-devel] avformat/ape: Error out in case of EOF in the header
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Commit Message

Michael Niedermayer July 24, 2020, 11:08 p.m. UTC
Fixes: OOM
Fixes: 24375/clusterfuzz-testcase-minimized-ffmpeg_DEMUXER_fuzzer-6216862443241472

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavformat/ape.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

Comments

Andreas Rheinhardt July 25, 2020, 4:10 a.m. UTC | #1
Michael Niedermayer:
> Fixes: OOM
> Fixes: 24375/clusterfuzz-testcase-minimized-ffmpeg_DEMUXER_fuzzer-6216862443241472
> 
> Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
> ---
>  libavformat/ape.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/libavformat/ape.c b/libavformat/ape.c
> index 39a584aa98..e966063ad7 100644
> --- a/libavformat/ape.c
> +++ b/libavformat/ape.c
> @@ -253,7 +253,7 @@ static int ape_read_header(AVFormatContext * s)
>              avio_skip(pb, ape->wavheaderlength);
>      }
>  
> -    if(!ape->totalframes){
> +    if(!ape->totalframes || pb->eof_reached){
>          av_log(s, AV_LOG_ERROR, "No frames in the file!\n");
>          return AVERROR(EINVAL);
>      }
> @@ -298,8 +298,10 @@ static int ape_read_header(AVFormatContext * s)
>              for (i = 0; i < ape->totalframes && !pb->eof_reached; i++)
>                  ape->bittable[i] = avio_r8(pb);
>          }
> -        if (pb->eof_reached)
> -            av_log(s, AV_LOG_WARNING, "File truncated\n");
> +        if (pb->eof_reached) {
> +            av_log(s, AV_LOG_ERROR, "File truncated\n");
> +            return AVERROR_INVALIDDATA;
> +        }

The above will lead to a memleak as long as cleaning up on read_header
failure is not automatic. Furthermore, it's the first of the checks that
fixes the OOM scenario, not the second, isn't it?

- Andreas

PS: One could remove the allocations for seek- and bittable altogether;
only ape_dumpinfo() needs to have the seektable, the bittable as well as
the frames at the same time.
Michael Niedermayer July 25, 2020, 6 p.m. UTC | #2
On Sat, Jul 25, 2020 at 06:10:44AM +0200, Andreas Rheinhardt wrote:
> Michael Niedermayer:
> > Fixes: OOM
> > Fixes: 24375/clusterfuzz-testcase-minimized-ffmpeg_DEMUXER_fuzzer-6216862443241472
> > 
> > Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> > Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
> > ---
> >  libavformat/ape.c | 8 +++++---
> >  1 file changed, 5 insertions(+), 3 deletions(-)
> > 
> > diff --git a/libavformat/ape.c b/libavformat/ape.c
> > index 39a584aa98..e966063ad7 100644
> > --- a/libavformat/ape.c
> > +++ b/libavformat/ape.c
> > @@ -253,7 +253,7 @@ static int ape_read_header(AVFormatContext * s)
> >              avio_skip(pb, ape->wavheaderlength);
> >      }
> >  
> > -    if(!ape->totalframes){
> > +    if(!ape->totalframes || pb->eof_reached){
> >          av_log(s, AV_LOG_ERROR, "No frames in the file!\n");
> >          return AVERROR(EINVAL);
> >      }
> > @@ -298,8 +298,10 @@ static int ape_read_header(AVFormatContext * s)
> >              for (i = 0; i < ape->totalframes && !pb->eof_reached; i++)
> >                  ape->bittable[i] = avio_r8(pb);
> >          }
> > -        if (pb->eof_reached)
> > -            av_log(s, AV_LOG_WARNING, "File truncated\n");
> > +        if (pb->eof_reached) {
> > +            av_log(s, AV_LOG_ERROR, "File truncated\n");
> > +            return AVERROR_INVALIDDATA;
> > +        }
> 
> The above will lead to a memleak as long as cleaning up on read_header
> failure is not automatic. Furthermore, it's the first of the checks that
> fixes the OOM scenario, not the second, isn't it?

yes, will apply with the leak issue fixed


> 
> - Andreas
> 
> PS: One could remove the allocations for seek- and bittable altogether;
> only ape_dumpinfo() needs to have the seektable, the bittable as well as
> the frames at the same time.

will post a patch doing that

thx

[...]
diff mbox series

Patch

diff --git a/libavformat/ape.c b/libavformat/ape.c
index 39a584aa98..e966063ad7 100644
--- a/libavformat/ape.c
+++ b/libavformat/ape.c
@@ -253,7 +253,7 @@  static int ape_read_header(AVFormatContext * s)
             avio_skip(pb, ape->wavheaderlength);
     }
 
-    if(!ape->totalframes){
+    if(!ape->totalframes || pb->eof_reached){
         av_log(s, AV_LOG_ERROR, "No frames in the file!\n");
         return AVERROR(EINVAL);
     }
@@ -298,8 +298,10 @@  static int ape_read_header(AVFormatContext * s)
             for (i = 0; i < ape->totalframes && !pb->eof_reached; i++)
                 ape->bittable[i] = avio_r8(pb);
         }
-        if (pb->eof_reached)
-            av_log(s, AV_LOG_WARNING, "File truncated\n");
+        if (pb->eof_reached) {
+            av_log(s, AV_LOG_ERROR, "File truncated\n");
+            return AVERROR_INVALIDDATA;
+        }
     }
 
     ape->frames[0].pos     = ape->firstframe;