| Message ID | 20230525214019.29048-1-michael@niedermayer.cc |
|---|---|
| State | New |
| Headers | show |
| Series | [FFmpeg-devel,1/5] avformat/mov: We do not support creation times of 300 billion years ago | expand |
| Context | Check | Description |
|---|---|---|
| andriy/make_x86 | success | Make finished |
| andriy/make_fate_x86 | success | Make fate finished |
On Thu, 25 May 2023, Michael Niedermayer wrote: > Fixes: signed integer overflow: -9223372036854775808 - 2082844800 cannot be represented in type 'long' > Fixes: 58384/clusterfuzz-testcase-minimized-ffmpeg_dem_MOV_fuzzer-6428383700713472 > > 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 | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/libavformat/mov.c b/libavformat/mov.c > index 9fdeef057e..3e2c4bc10d 100644 > --- a/libavformat/mov.c > +++ b/libavformat/mov.c > @@ -1530,6 +1530,10 @@ static void mov_metadata_creation_time(MOVContext *c, AVIOContext *pb, AVDiction > } > } > if (time) { > + if (time < INT64_MIN + 2082844800) { > + av_log(c->fc, AV_LOG_DEBUG, "creation_time predates big bang\n"); > + return; > + } Actually creation_time is unsigned, so it cannot be negative. I suggest you simply reject everyting less than 0 here. You should also move the check to the version == 1 case, because only that can read a "negative" value. Regards, Marton
On Sun, May 28, 2023 at 08:53:49PM +0200, Marton Balint wrote: > > > On Thu, 25 May 2023, Michael Niedermayer wrote: > > > Fixes: signed integer overflow: -9223372036854775808 - 2082844800 cannot be represented in type 'long' > > Fixes: 58384/clusterfuzz-testcase-minimized-ffmpeg_dem_MOV_fuzzer-6428383700713472 > > > > 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 | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/libavformat/mov.c b/libavformat/mov.c > > index 9fdeef057e..3e2c4bc10d 100644 > > --- a/libavformat/mov.c > > +++ b/libavformat/mov.c > > @@ -1530,6 +1530,10 @@ static void mov_metadata_creation_time(MOVContext *c, AVIOContext *pb, AVDiction > > } > > } > > if (time) { > > + if (time < INT64_MIN + 2082844800) { > > + av_log(c->fc, AV_LOG_DEBUG, "creation_time predates big bang\n"); > > + return; > > + } > > Actually creation_time is unsigned, so it cannot be negative. I suggest you > simply reject everyting less than 0 here. You should also move the check to > the version == 1 case, because only that can read a "negative" value. ok will apply with these changes thx [...]
diff --git a/libavformat/mov.c b/libavformat/mov.c index 9fdeef057e..3e2c4bc10d 100644 --- a/libavformat/mov.c +++ b/libavformat/mov.c @@ -1530,6 +1530,10 @@ static void mov_metadata_creation_time(MOVContext *c, AVIOContext *pb, AVDiction } } if (time) { + if (time < INT64_MIN + 2082844800) { + av_log(c->fc, AV_LOG_DEBUG, "creation_time predates big bang\n"); + return; + } time -= 2082844800; /* seconds between 1904-01-01 and Epoch */ if ((int64_t)(time * 1000000ULL) / 1000000 != time) {
Fixes: signed integer overflow: -9223372036854775808 - 2082844800 cannot be represented in type 'long' Fixes: 58384/clusterfuzz-testcase-minimized-ffmpeg_dem_MOV_fuzzer-6428383700713472 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 | 4 ++++ 1 file changed, 4 insertions(+)