From c2ed905b68d79d4e7823aae69578cdbf2bf191af Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 26 Mar 2023 20:31:05 +0200 Subject: [PATCH] avcodec/vc1dec: Use av_fast_realloc() for slices Fixes: Timeout Fixes: 57281/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_VC1IMAGE_fuzzer-4594141064724480 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/vc1dec.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/libavcodec/vc1dec.c b/libavcodec/vc1dec.c index 5cb4c544c9..18fb616fff 100644 --- a/libavcodec/vc1dec.c +++ b/libavcodec/vc1dec.c @@ -836,6 +836,7 @@ static int vc1_decode_frame(AVCodecContext *avctx, AVFrame *pict, const uint8_t *rawbuf; int raw_size; } *slices = NULL, *tmp; + unsigned slices_allocated = 0; v->second_field = 0; @@ -859,6 +860,7 @@ static int vc1_decode_frame(AVCodecContext *avctx, AVFrame *pict, //for advanced profile we may need to parse and unescape data if (avctx->codec_id == AV_CODEC_ID_VC1 || avctx->codec_id == AV_CODEC_ID_VC1IMAGE) { int buf_size2 = 0; + size_t next_allocated = 0; buf2 = av_mallocz(buf_size + AV_INPUT_BUFFER_PADDING_SIZE); if (!buf2) return AVERROR(ENOMEM); @@ -882,7 +884,8 @@ static int vc1_decode_frame(AVCodecContext *avctx, AVFrame *pict, int buf_size3; if (avctx->hwaccel) buf_start_second_field = start; - tmp = av_realloc_array(slices, sizeof(*slices), n_slices+1); + av_size_mult(sizeof(*slices), n_slices+1, &next_allocated); + tmp = next_allocated ? av_fast_realloc(slices, &slices_allocated, next_allocated) : NULL; if (!tmp) { ret = AVERROR(ENOMEM); goto err; @@ -911,7 +914,8 @@ static int vc1_decode_frame(AVCodecContext *avctx, AVFrame *pict, break; case VC1_CODE_SLICE: { int buf_size3; - tmp = av_realloc_array(slices, sizeof(*slices), n_slices+1); + av_size_mult(sizeof(*slices), n_slices+1, &next_allocated); + tmp = next_allocated ? av_fast_realloc(slices, &slices_allocated, next_allocated) : NULL; if (!tmp) { ret = AVERROR(ENOMEM); goto err; @@ -946,7 +950,8 @@ static int vc1_decode_frame(AVCodecContext *avctx, AVFrame *pict, } else { // found field marker, unescape second field if (avctx->hwaccel) buf_start_second_field = divider; - tmp = av_realloc_array(slices, sizeof(*slices), n_slices+1); + av_size_mult(sizeof(*slices), n_slices+1, &next_allocated); + tmp = next_allocated ? av_fast_realloc(slices, &slices_allocated, next_allocated) : NULL; if (!tmp) { ret = AVERROR(ENOMEM); goto err;