From a73579c12d665531df9765c5b75aed5e12441d94 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Mon, 27 Aug 2018 00:49:00 +0200 Subject: [PATCH] iavcodec/zmbv: Avoid reallocating cur/prev buffers if they are large enough Fixes: Timeout Fixes: 9721/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ZMBV_fuzzer-5650321660444672 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/zmbv.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/libavcodec/zmbv.c b/libavcodec/zmbv.c index 251a72cf31..b01ce1bcf6 100644 --- a/libavcodec/zmbv.c +++ b/libavcodec/zmbv.c @@ -57,6 +57,7 @@ typedef struct ZmbvContext { AVCodecContext *avctx; int bpp; + int alloc_bpp; unsigned int decomp_size; uint8_t* decomp_buf; uint8_t pal[768]; @@ -494,12 +495,17 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPac return AVERROR_UNKNOWN; } - c->cur = av_realloc_f(c->cur, avctx->width * avctx->height, (c->bpp / 8)); - c->prev = av_realloc_f(c->prev, avctx->width * avctx->height, (c->bpp / 8)); + if (c->alloc_bpp < c->bpp) { + c->cur = av_realloc_f(c->cur, avctx->width * avctx->height, (c->bpp / 8)); + c->prev = av_realloc_f(c->prev, avctx->width * avctx->height, (c->bpp / 8)); + c->alloc_bpp = c->bpp; + } c->bx = (c->width + c->bw - 1) / c->bw; c->by = (c->height+ c->bh - 1) / c->bh; - if (!c->cur || !c->prev) + if (!c->cur || !c->prev) { + c->alloc_bpp = 0; return AVERROR(ENOMEM); + } memset(c->cur, 0, avctx->width * avctx->height * (c->bpp / 8)); memset(c->prev, 0, avctx->width * avctx->height * (c->bpp / 8)); c->decode_intra= decode_intra;