| Message ID | 20210427192135.17286-2-michael@niedermayer.cc |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [FFmpeg-devel,1/4] avformat/rmdec: Check old_format len for overflow | expand |
| Context | Check | Description |
|---|---|---|
| andriy/x86_make | success | Make finished |
| andriy/x86_make_fate | success | Make fate finished |
| andriy/PPC64_make | success | Make finished |
| andriy/PPC64_make_fate | success | Make fate finished |
Michael Niedermayer: > Fixes: signed integer overflow: 777777776 * 4 cannot be represented in type 'int' > Fixes: 29102/clusterfuzz-testcase-minimized-ffmpeg_dem_RPL_fuzzer-6726188921913344 > > Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg > Signed-off-by: Michael Niedermayer <michael@niedermayer.cc> > --- > libavformat/rpl.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/libavformat/rpl.c b/libavformat/rpl.c > index b98488c7b1..558e5718ba 100644 > --- a/libavformat/rpl.c > +++ b/libavformat/rpl.c > @@ -207,8 +207,10 @@ static int rpl_read_header(AVFormatContext *s) > ast->codecpar->bits_per_coded_sample = 4; > > ast->codecpar->bit_rate = ast->codecpar->sample_rate * > - ast->codecpar->bits_per_coded_sample * > - ast->codecpar->channels; > + (int64_t)ast->codecpar->bits_per_coded_sample; > + if (ast->codecpar->bit_rate > INT64_MAX / ast->codecpar->channels) > + return AVERROR_INVALIDDATA; > + ast->codecpar->bit_rate *= ast->codecpar->channels; > > ast->codecpar->codec_id = AV_CODEC_ID_NONE; > switch (audio_format) { > read_line_and_int() can return zero and so you must not divide by channels. (Something like __builtin_smulll_overflow() might be advantageous here.) - Andreas
On Tue, Apr 27, 2021 at 09:31:56PM +0200, Andreas Rheinhardt wrote: > Michael Niedermayer: > > Fixes: signed integer overflow: 777777776 * 4 cannot be represented in type 'int' > > Fixes: 29102/clusterfuzz-testcase-minimized-ffmpeg_dem_RPL_fuzzer-6726188921913344 > > > > Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg > > Signed-off-by: Michael Niedermayer <michael@niedermayer.cc> > > --- > > libavformat/rpl.c | 6 ++++-- > > 1 file changed, 4 insertions(+), 2 deletions(-) > > > > diff --git a/libavformat/rpl.c b/libavformat/rpl.c > > index b98488c7b1..558e5718ba 100644 > > --- a/libavformat/rpl.c > > +++ b/libavformat/rpl.c > > @@ -207,8 +207,10 @@ static int rpl_read_header(AVFormatContext *s) > > ast->codecpar->bits_per_coded_sample = 4; > > > > ast->codecpar->bit_rate = ast->codecpar->sample_rate * > > - ast->codecpar->bits_per_coded_sample * > > - ast->codecpar->channels; > > + (int64_t)ast->codecpar->bits_per_coded_sample; > > + if (ast->codecpar->bit_rate > INT64_MAX / ast->codecpar->channels) > > + return AVERROR_INVALIDDATA; > > + ast->codecpar->bit_rate *= ast->codecpar->channels; > > > > ast->codecpar->codec_id = AV_CODEC_ID_NONE; > > switch (audio_format) { > > > read_line_and_int() can return zero and so you must not divide by > channels. (Something like __builtin_smulll_overflow() might be > advantageous here.) hmm, i saw bits_per_coded_sample cant be 0 and wanted to use that but clearly i didnt, fascinating. will switch channels out with bits_per_coded_sample thx [...]
diff --git a/libavformat/rpl.c b/libavformat/rpl.c index b98488c7b1..558e5718ba 100644 --- a/libavformat/rpl.c +++ b/libavformat/rpl.c @@ -207,8 +207,10 @@ static int rpl_read_header(AVFormatContext *s) ast->codecpar->bits_per_coded_sample = 4; ast->codecpar->bit_rate = ast->codecpar->sample_rate * - ast->codecpar->bits_per_coded_sample * - ast->codecpar->channels; + (int64_t)ast->codecpar->bits_per_coded_sample; + if (ast->codecpar->bit_rate > INT64_MAX / ast->codecpar->channels) + return AVERROR_INVALIDDATA; + ast->codecpar->bit_rate *= ast->codecpar->channels; ast->codecpar->codec_id = AV_CODEC_ID_NONE; switch (audio_format) {
Fixes: signed integer overflow: 777777776 * 4 cannot be represented in type 'int' Fixes: 29102/clusterfuzz-testcase-minimized-ffmpeg_dem_RPL_fuzzer-6726188921913344 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer <michael@niedermayer.cc> --- libavformat/rpl.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)