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avcodec/prosumer: Error out if decompress() stops reading data

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if 0 is encountered in the LUT then decompress() will continue to output 0 bytes but never read more data.
Without a specification it is impossible to say if this is invalid or a feature.
None of the valid prosumer files tested cause a 0 to be read, so it is likely
not a intended feature.

Fixes: Timeout
Fixes: 11266/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_PROSUMER_fuzzer-5681827423977472

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 62f8d27ef1995354d6529ea0d9428501d7f914b4)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2019-01-12 22:36:00 +01:00
parent 552733d48b
commit 31fa50f3d9
1 changed files with 5 additions and 2 deletions
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7
libavcodec/prosumer.c
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@ -99,6 +99,8 @@ static int decompress(GetByteContext *gb, int size, PutByteContext *pb, const ui
}
idx = a >> 20;
b = lut[2 * idx];
if (!b)
return AVERROR_INVALIDDATA;
continue;
}
idx = 2;
@ -159,8 +161,9 @@ static int decode_frame(AVCodecContext *avctx, void *data,
memset(s->decbuffer, 0, s->size);
bytestream2_init(&s->gb, avpkt->data, avpkt->size);
bytestream2_init_writer(&s->pb, s->decbuffer, s->size);
decompress(&s->gb, AV_RL32(avpkt->data + 28) >> 1, &s->pb, s->lut);
ret = decompress(&s->gb, AV_RL32(avpkt->data + 28) >> 1, &s->pb, s->lut);
if (ret < 0)
return ret;
vertical_predict((uint32_t *)s->decbuffer, 0, (uint32_t *)s->initial_line, s->stride, 1);
vertical_predict((uint32_t *)s->decbuffer, s->stride, (uint32_t *)s->decbuffer, s->stride, avctx->height - 1);