From 31fa50f3d97ca4c722e2b35af7b66a4b44a8f46a Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sat, 12 Jan 2019 22:36:00 +0100 Subject: [PATCH] avcodec/prosumer: Error out if decompress() stops reading data 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 (cherry picked from commit 62f8d27ef1995354d6529ea0d9428501d7f914b4) Signed-off-by: Michael Niedermayer --- libavcodec/prosumer.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/libavcodec/prosumer.c b/libavcodec/prosumer.c index 505de71980..93f0c84d3a 100644 --- a/libavcodec/prosumer.c +++ b/libavcodec/prosumer.c @@ -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);