| Message ID | 20190618235303.8738-3-michael@niedermayer.cc |
|---|---|
| State | Accepted |
| Commit | a6474b899c1153e3bb95e399b6605c3507aea0d0 |
| Headers | show |
On Wed, Jun 19, 2019 at 01:53:03AM +0200, Michael Niedermayer wrote: > lpc_quant of 0 produces undefined behavior, thus disallow this. > If valid samples use this then such a sample would be quite > usefull to confirm the correct&lossles handling of this. > > Fixes: libavcodec/alac.c:218:25: runtime error: shift exponent -1 is negative > Fixes: 15273/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ALAC_fuzzer-5656388535058432 > Fixes: 15276/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ALAC_fuzzer-5761238417539072 > Fixes: 15315/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ALAC_fuzzer-5767260766994432 > > Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg > Signed-off-by: Michael Niedermayer <michael@niedermayer.cc> > --- > libavcodec/alac.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) will apply [...]
diff --git a/libavcodec/alac.c b/libavcodec/alac.c index 2f44340661..c234d7153b 100644 --- a/libavcodec/alac.c +++ b/libavcodec/alac.c @@ -306,7 +306,7 @@ static int decode_element(AVCodecContext *avctx, AVFrame *frame, int ch_index, rice_history_mult[ch] = get_bits(&alac->gb, 3); lpc_order[ch] = get_bits(&alac->gb, 5); - if (lpc_order[ch] >= alac->max_samples_per_frame) + if (lpc_order[ch] >= alac->max_samples_per_frame || !lpc_quant[ch]) return AVERROR_INVALIDDATA; /* read the predictor table */
lpc_quant of 0 produces undefined behavior, thus disallow this. If valid samples use this then such a sample would be quite usefull to confirm the correct&lossles handling of this. Fixes: libavcodec/alac.c:218:25: runtime error: shift exponent -1 is negative Fixes: 15273/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ALAC_fuzzer-5656388535058432 Fixes: 15276/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ALAC_fuzzer-5761238417539072 Fixes: 15315/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ALAC_fuzzer-5767260766994432 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer <michael@niedermayer.cc> --- libavcodec/alac.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)