| Message ID | 20221112234401.24158-3-michael@niedermayer.cc |
|---|---|
| State | New |
| Headers | show |
| Series | [FFmpeg-devel,1/3] avformat/lafdec: Check for EOF in header reading | expand |
| Context | Check | Description |
|---|---|---|
| yinshiyou/make_loongarch64 | success | Make finished |
| yinshiyou/make_fate_loongarch64 | success | Make fate finished |
| andriy/make_x86 | success | Make finished |
| andriy/make_fate_x86 | success | Make fate finished |
sön 2022-11-13 klockan 00:44 +0100 skrev Michael Niedermayer: > Fixes: signed integer overflow: -3741319169 - 9223372036823449370 > cannot be represented in type 'long' > Fixes: 51896/clusterfuzz-testcase-minimized-ffmpeg_dem_MXF_fuzzer- > 513039428681728 > > Found-by: continuous fuzzing process > https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg > Signed-off-by: Michael Niedermayer <michael@niedermayer.cc> > --- > libavformat/mxfdec.c | 10 +++++++--- > 1 file changed, 7 insertions(+), 3 deletions(-) > > diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c > index e6118e141d..42109cb43a 100644 > --- a/libavformat/mxfdec.c > +++ b/libavformat/mxfdec.c > @@ -100,7 +100,7 @@ typedef struct MXFPartition { > uint64_t previous_partition; > int index_sid; > int body_sid; > - int64_t this_partition; > + uint64_t this_partition; > int64_t essence_offset; ///< absolute offset of essence > int64_t essence_length; > int32_t kag_size; > @@ -3519,8 +3519,12 @@ static void > mxf_compute_essence_containers(AVFormatContext *s) > p->essence_offset = p->first_essence_klv.offset; > > /* essence container spans to the next partition */ > - if (x < mxf->partitions_count - 1) > - p->essence_length = mxf- > >partitions[x+1].this_partition - p->essence_offset; > + if (x < mxf->partitions_count - 1) { > + if (mxf->partitions[x+1].this_partition < p- > >essence_offset) { > + p->essence_length = -1; > + } else > + p->essence_length = mxf- > >partitions[x+1].this_partition - p->essence_offset; > + } A better solution might be to record the actual offset of the partitions rather than relying on ThisPartition. Then we can guarantee that they are strictly increasing. /Tomas
On Wed, Nov 16, 2022 at 12:49:10PM +0100, Tomas Härdin wrote: > sön 2022-11-13 klockan 00:44 +0100 skrev Michael Niedermayer: > > Fixes: signed integer overflow: -3741319169 - 9223372036823449370 > > cannot be represented in type 'long' > > Fixes: 51896/clusterfuzz-testcase-minimized-ffmpeg_dem_MXF_fuzzer- > > 513039428681728 > > > > Found-by: continuous fuzzing process > > https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg > > Signed-off-by: Michael Niedermayer <michael@niedermayer.cc> > > --- > > libavformat/mxfdec.c | 10 +++++++--- > > 1 file changed, 7 insertions(+), 3 deletions(-) > > > > diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c > > index e6118e141d..42109cb43a 100644 > > --- a/libavformat/mxfdec.c > > +++ b/libavformat/mxfdec.c > > @@ -100,7 +100,7 @@ typedef struct MXFPartition { > > uint64_t previous_partition; > > int index_sid; > > int body_sid; > > - int64_t this_partition; > > + uint64_t this_partition; > > int64_t essence_offset; ///< absolute offset of essence > > int64_t essence_length; > > int32_t kag_size; > > @@ -3519,8 +3519,12 @@ static void > > mxf_compute_essence_containers(AVFormatContext *s) > > p->essence_offset = p->first_essence_klv.offset; > > > > /* essence container spans to the next partition */ > > - if (x < mxf->partitions_count - 1) > > - p->essence_length = mxf- > > >partitions[x+1].this_partition - p->essence_offset; > > + if (x < mxf->partitions_count - 1) { > > + if (mxf->partitions[x+1].this_partition < p- > > >essence_offset) { > > + p->essence_length = -1; > > + } else > > + p->essence_length = mxf- > > >partitions[x+1].this_partition - p->essence_offset; > > + } > > A better solution might be to record the actual offset of the > partitions rather than relying on ThisPartition. Then we can guarantee > that they are strictly increasing. do you mean that pack_ofs could be used here ? (this is within 8 byte of this_partition) for the files i checked or something else ? but as pack_ofs is signed that either means dealing with potentially negative or changing it to uint64_t or adding a new field and avio_tell() somewhere? thx [...]
fre 2022-12-23 klockan 00:25 +0100 skrev Michael Niedermayer: > On Wed, Nov 16, 2022 at 12:49:10PM +0100, Tomas Härdin wrote: > > sön 2022-11-13 klockan 00:44 +0100 skrev Michael Niedermayer: > > > Fixes: signed integer overflow: -3741319169 - 9223372036823449370 > > > cannot be represented in type 'long' > > > Fixes: 51896/clusterfuzz-testcase-minimized- > > > ffmpeg_dem_MXF_fuzzer- > > > 513039428681728 > > > > > > Found-by: continuous fuzzing process > > > https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg > > > Signed-off-by: Michael Niedermayer <michael@niedermayer.cc> > > > --- > > > libavformat/mxfdec.c | 10 +++++++--- > > > 1 file changed, 7 insertions(+), 3 deletions(-) > > > > > > diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c > > > index e6118e141d..42109cb43a 100644 > > > --- a/libavformat/mxfdec.c > > > +++ b/libavformat/mxfdec.c > > > @@ -100,7 +100,7 @@ typedef struct MXFPartition { > > > uint64_t previous_partition; > > > int index_sid; > > > int body_sid; > > > - int64_t this_partition; > > > + uint64_t this_partition; > > > int64_t essence_offset; ///< absolute offset of > > > essence > > > int64_t essence_length; > > > int32_t kag_size; > > > @@ -3519,8 +3519,12 @@ static void > > > mxf_compute_essence_containers(AVFormatContext *s) > > > p->essence_offset = p->first_essence_klv.offset; > > > > > > /* essence container spans to the next partition */ > > > - if (x < mxf->partitions_count - 1) > > > - p->essence_length = mxf- > > > > partitions[x+1].this_partition - p->essence_offset; > > > + if (x < mxf->partitions_count - 1) { > > > + if (mxf->partitions[x+1].this_partition < p- > > > > essence_offset) { > > > + p->essence_length = -1; > > > + } else > > > + p->essence_length = mxf- > > > > partitions[x+1].this_partition - p->essence_offset; > > > + } > > > > A better solution might be to record the actual offset of the > > partitions rather than relying on ThisPartition. Then we can > > guarantee > > that they are strictly increasing. > > do you mean that pack_ofs could be used here ? this_partition should be == pack_ofs - run_in. I think we can just nuke this_partition in the struct and use pack_ofs - run_in everywhere. Emit a warning or bail out if any partition does not obey this contraint, since such files have likely been written by bad muxers. > but as pack_ofs is signed that either means dealing with potentially > negative > or changing it to uint64_t or adding a new field and avio_tell() > somewhere? pack_ofs can only be negative in case of error, in which case we should bail out anyway. Something must be very wrong if lavf can't avio_tell() For every partition, pack_ofs >= run_in. this_partition >= 0, and in particular this_partition == 0 for the very first partition. This is reminding me that I had some finer points to fix related to run_in and deleting the superfluous sync stuff that's currently in the code. Baptiste is fine with that, as it's a relic from when mxfdec didn't have proper seek support. /Tomas
On Fri, Dec 23, 2022 at 12:47:02PM +0100, Tomas Härdin wrote: > fre 2022-12-23 klockan 00:25 +0100 skrev Michael Niedermayer: > > On Wed, Nov 16, 2022 at 12:49:10PM +0100, Tomas Härdin wrote: > > > sön 2022-11-13 klockan 00:44 +0100 skrev Michael Niedermayer: > > > > Fixes: signed integer overflow: -3741319169 - 9223372036823449370 > > > > cannot be represented in type 'long' > > > > Fixes: 51896/clusterfuzz-testcase-minimized- > > > > ffmpeg_dem_MXF_fuzzer- > > > > 513039428681728 > > > > > > > > Found-by: continuous fuzzing process > > > > https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg > > > > Signed-off-by: Michael Niedermayer <michael@niedermayer.cc> > > > > --- > > > > libavformat/mxfdec.c | 10 +++++++--- > > > > 1 file changed, 7 insertions(+), 3 deletions(-) > > > > > > > > diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c > > > > index e6118e141d..42109cb43a 100644 > > > > --- a/libavformat/mxfdec.c > > > > +++ b/libavformat/mxfdec.c > > > > @@ -100,7 +100,7 @@ typedef struct MXFPartition { > > > > uint64_t previous_partition; > > > > int index_sid; > > > > int body_sid; > > > > - int64_t this_partition; > > > > + uint64_t this_partition; > > > > int64_t essence_offset; ///< absolute offset of > > > > essence > > > > int64_t essence_length; > > > > int32_t kag_size; > > > > @@ -3519,8 +3519,12 @@ static void > > > > mxf_compute_essence_containers(AVFormatContext *s) > > > > p->essence_offset = p->first_essence_klv.offset; > > > > > > > > /* essence container spans to the next partition */ > > > > - if (x < mxf->partitions_count - 1) > > > > - p->essence_length = mxf- > > > > > partitions[x+1].this_partition - p->essence_offset; > > > > + if (x < mxf->partitions_count - 1) { > > > > + if (mxf->partitions[x+1].this_partition < p- > > > > > essence_offset) { > > > > + p->essence_length = -1; > > > > + } else > > > > + p->essence_length = mxf- > > > > > partitions[x+1].this_partition - p->essence_offset; > > > > + } > > > > > > A better solution might be to record the actual offset of the > > > partitions rather than relying on ThisPartition. Then we can > > > guarantee > > > that they are strictly increasing. > > > > do you mean that pack_ofs could be used here ? > > this_partition should be == pack_ofs - run_in. I think we can just nuke > this_partition in the struct and use pack_ofs - run_in everywhere. Emit > a warning or bail out if any partition does not obey this contraint, > since such files have likely been written by bad muxers. ill post a patch doing that thx [...]
diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c index e6118e141d..42109cb43a 100644 --- a/libavformat/mxfdec.c +++ b/libavformat/mxfdec.c @@ -100,7 +100,7 @@ typedef struct MXFPartition { uint64_t previous_partition; int index_sid; int body_sid; - int64_t this_partition; + uint64_t this_partition; int64_t essence_offset; ///< absolute offset of essence int64_t essence_length; int32_t kag_size; @@ -3519,8 +3519,12 @@ static void mxf_compute_essence_containers(AVFormatContext *s) p->essence_offset = p->first_essence_klv.offset; /* essence container spans to the next partition */ - if (x < mxf->partitions_count - 1) - p->essence_length = mxf->partitions[x+1].this_partition - p->essence_offset; + if (x < mxf->partitions_count - 1) { + if (mxf->partitions[x+1].this_partition < p->essence_offset) { + p->essence_length = -1; + } else + p->essence_length = mxf->partitions[x+1].this_partition - p->essence_offset; + } if (p->essence_length < 0) { /* next ThisPartition < essence_offset */
Fixes: signed integer overflow: -3741319169 - 9223372036823449370 cannot be represented in type 'long' Fixes: 51896/clusterfuzz-testcase-minimized-ffmpeg_dem_MXF_fuzzer-513039428681728 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer <michael@niedermayer.cc> --- libavformat/mxfdec.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)