| Message ID | 20200623001458.15855-1-michael@niedermayer.cc |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [FFmpeg-devel,1/2] avformat/mvdec: Fix integer overflow with billions of channels | expand |
| Context | Check | Description |
|---|---|---|
| andriy/default | pending | |
| andriy/make | success | Make finished |
| andriy/make_fate | success | Make fate finished |
Michael Niedermayer: > Fixes: signed integer overflow: 1394614304 * 2 cannot be represented in type 'int' > Fixes: 23491/clusterfuzz-testcase-minimized-ffmpeg_DEMUXER_fuzzer-5697377020411904 > > Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg > Signed-off-by: Michael Niedermayer <michael@niedermayer.cc> > --- > libavformat/mvdec.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/libavformat/mvdec.c b/libavformat/mvdec.c > index 64166a84b1..fa87384c6b 100644 > --- a/libavformat/mvdec.c > +++ b/libavformat/mvdec.c > @@ -355,7 +355,7 @@ static int mv_read_header(AVFormatContext *avctx) > avio_skip(pb, 8); > av_add_index_entry(ast, pos, timestamp, asize, 0, AVINDEX_KEYFRAME); > av_add_index_entry(vst, pos + asize, i, vsize, 0, AVINDEX_KEYFRAME); > - timestamp += asize / (ast->codecpar->channels * 2); > + timestamp += asize / (ast->codecpar->channels * 2LL); > } > } else if (!version && avio_rb16(pb) == 3) { > avio_skip(pb, 4); > You could avoid using 64 the 64 bit intermediate by multiplying with 2U or by using asize / ast->codecpar->channels / 2. Whatever you prefer should also be applied to read_index. - Andreas
On Tue, Jun 23, 2020 at 05:22:53AM +0200, Andreas Rheinhardt wrote: > Michael Niedermayer: > > Fixes: signed integer overflow: 1394614304 * 2 cannot be represented in type 'int' > > Fixes: 23491/clusterfuzz-testcase-minimized-ffmpeg_DEMUXER_fuzzer-5697377020411904 > > > > Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg > > Signed-off-by: Michael Niedermayer <michael@niedermayer.cc> > > --- > > libavformat/mvdec.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/libavformat/mvdec.c b/libavformat/mvdec.c > > index 64166a84b1..fa87384c6b 100644 > > --- a/libavformat/mvdec.c > > +++ b/libavformat/mvdec.c > > @@ -355,7 +355,7 @@ static int mv_read_header(AVFormatContext *avctx) > > avio_skip(pb, 8); > > av_add_index_entry(ast, pos, timestamp, asize, 0, AVINDEX_KEYFRAME); > > av_add_index_entry(vst, pos + asize, i, vsize, 0, AVINDEX_KEYFRAME); > > - timestamp += asize / (ast->codecpar->channels * 2); > > + timestamp += asize / (ast->codecpar->channels * 2LL); > > } > > } else if (!version && avio_rb16(pb) == 3) { > > avio_skip(pb, 4); > > > You could avoid using 64 the 64 bit intermediate by multiplying with 2U > or by using asize / ast->codecpar->channels / 2. > > Whatever you prefer should also be applied to read_index. will apply to both thanks [...]
diff --git a/libavformat/mvdec.c b/libavformat/mvdec.c index 64166a84b1..fa87384c6b 100644 --- a/libavformat/mvdec.c +++ b/libavformat/mvdec.c @@ -355,7 +355,7 @@ static int mv_read_header(AVFormatContext *avctx) avio_skip(pb, 8); av_add_index_entry(ast, pos, timestamp, asize, 0, AVINDEX_KEYFRAME); av_add_index_entry(vst, pos + asize, i, vsize, 0, AVINDEX_KEYFRAME); - timestamp += asize / (ast->codecpar->channels * 2); + timestamp += asize / (ast->codecpar->channels * 2LL); } } else if (!version && avio_rb16(pb) == 3) { avio_skip(pb, 4);
Fixes: signed integer overflow: 1394614304 * 2 cannot be represented in type 'int' Fixes: 23491/clusterfuzz-testcase-minimized-ffmpeg_DEMUXER_fuzzer-5697377020411904 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer <michael@niedermayer.cc> --- libavformat/mvdec.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)