From 17f91c07ef4c04b80d5b09dc3baa64dec161e307 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Wed, 1 May 2019 19:43:40 +0200 Subject: [PATCH] avcodec/prosumer: Only memset(0) what is needed. Fixes: Timeout (11sec -> 0.08sec) Fixes: 14406/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_PROSUMER_fuzzer-5151210148986880 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/prosumer.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/libavcodec/prosumer.c b/libavcodec/prosumer.c index f064f7bad7..9950519604 100644 --- a/libavcodec/prosumer.c +++ b/libavcodec/prosumer.c @@ -153,7 +153,6 @@ static int decode_frame(AVCodecContext *avctx, void *data, if (avpkt->size <= 32) return AVERROR_INVALIDDATA; - memset(s->decbuffer, 0, s->size); bytestream2_init(&s->gb, avpkt->data, avpkt->size); bytestream2_init_writer(&s->pb, s->decbuffer, s->size); ret = decompress(&s->gb, AV_RL32(avpkt->data + 28) >> 1, &s->pb, s->lut); @@ -161,6 +160,10 @@ static int decode_frame(AVCodecContext *avctx, void *data, return ret; if (bytestream2_get_bytes_left_p(&s->pb) > s->size * (int64_t)avctx->discard_damaged_percentage / 100) return AVERROR_INVALIDDATA; + + av_assert0(s->size >= bytestream2_get_bytes_left_p(&s->pb)); + memset(s->decbuffer + bytestream2_tell_p(&s->pb), 0, bytestream2_get_bytes_left_p(&s->pb)); + 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);