[FFmpeg-devel] [PATCH] avformat/mov: sanity check count in IPRP

[FFmpeg-devel] [PATCH] avformat/mov: sanity check count in IPRP

[Michael Niedermayer]

Fixes: Timeout
Fixes: 69230/clusterfuzz-testcase-minimized-ffmpeg_IO_DEMUXER_fuzzer-6540512101203968

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

diff --git a/libavformat/mov.c b/libavformat/mov.c
index ce95842ce58..9042753d221 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -8925,6 +8925,11 @@ static int mov_read_iprp(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     flags   = avio_rb24(pb);
     count   = avio_rb32(pb);
 
+    if (count * 5LL > a.size) {
+        ret = AVERROR_INVALIDDATA;
+        goto fail;
+    }
+
     for (int i = 0; i < count; i++) {
         int item_id = version ? avio_rb32(pb) : avio_rb16(pb);
         int assoc_count = avio_r8(pb);
-- 
2.45.2

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Re: [FFmpeg-devel] [PATCH] avformat/mov: sanity check count in IPRP

[James Almer]

On 7/16/2024 10:19 AM, Michael Niedermayer wrote:
> Fixes: Timeout
> Fixes: 69230/clusterfuzz-testcase-minimized-ffmpeg_IO_DEMUXER_fuzzer-6540512101203968
> 
> Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
> ---
>   libavformat/mov.c | 5 +++++
>   1 file changed, 5 insertions(+)
> 
> diff --git a/libavformat/mov.c b/libavformat/mov.c
> index ce95842ce58..9042753d221 100644
> --- a/libavformat/mov.c
> +++ b/libavformat/mov.c
> @@ -8925,6 +8925,11 @@ static int mov_read_iprp(MOVContext *c, AVIOContext *pb, MOVAtom atom)
>       flags   = avio_rb24(pb);
>       count   = avio_rb32(pb);
>   
> +    if (count * 5LL > a.size) {
> +        ret = AVERROR_INVALIDDATA;
> +        goto fail;
> +    }

a.size is also read from the aviocontext, so i think it'd be better to 
add an avio_feof() check inside the for loop below, after assoc_count is 
read.

> +
>       for (int i = 0; i < count; i++) {
>           int item_id = version ? avio_rb32(pb) : avio_rb16(pb);
>           int assoc_count = avio_r8(pb);
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Re: [FFmpeg-devel] [PATCH] avformat/mov: sanity check count in IPRP

[Michael Niedermayer]

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On Tue, Jul 16, 2024 at 10:31:54AM -0300, James Almer wrote:
> On 7/16/2024 10:19 AM, Michael Niedermayer wrote:
> > Fixes: Timeout
> > Fixes: 69230/clusterfuzz-testcase-minimized-ffmpeg_IO_DEMUXER_fuzzer-6540512101203968
> > 
> > Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> > Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
> > ---
> >   libavformat/mov.c | 5 +++++
> >   1 file changed, 5 insertions(+)
> > 
> > diff --git a/libavformat/mov.c b/libavformat/mov.c
> > index ce95842ce58..9042753d221 100644
> > --- a/libavformat/mov.c
> > +++ b/libavformat/mov.c
> > @@ -8925,6 +8925,11 @@ static int mov_read_iprp(MOVContext *c, AVIOContext *pb, MOVAtom atom)
> >       flags   = avio_rb24(pb);
> >       count   = avio_rb32(pb);
> > +    if (count * 5LL > a.size) {
> > +        ret = AVERROR_INVALIDDATA;
> > +        goto fail;
> > +    }
> 
> a.size is also read from the aviocontext, so i think it'd be better to add
> an avio_feof() check inside the for loop below, after assoc_count is read.

ok will apply with that solution

thx

[...]
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Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

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