From 31916d3d9fc61bab50ccbcc2d58bf7e7efb6c8a0 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Fri, 18 Mar 2022 00:11:28 +0100 Subject: [PATCH] avcodec/alsdec: Set channels from data after data is set Fixes: out of array write Fixes: 45624/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ALS_fuzzer-6473487382872064 Fixes: 45626/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ALS_fuzzer-4874997192065024 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Reviewed-by: James Almer Signed-off-by: Michael Niedermayer --- libavcodec/alsdec.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/libavcodec/alsdec.c b/libavcodec/alsdec.c index 822cf211b0..73af829178 100644 --- a/libavcodec/alsdec.c +++ b/libavcodec/alsdec.c @@ -1986,7 +1986,7 @@ static av_cold int decode_init(AVCodecContext *avctx) unsigned int c; unsigned int channel_size; int num_buffers, ret; - int channels = avctx->ch_layout.nb_channels; + int channels; ALSDecContext *ctx = avctx->priv_data; ALSSpecificConfig *sconf = &ctx->sconf; ctx->avctx = avctx; @@ -2000,6 +2000,7 @@ static av_cold int decode_init(AVCodecContext *avctx) av_log(avctx, AV_LOG_ERROR, "Reading ALSSpecificConfig failed.\n"); return ret; } + channels = avctx->ch_layout.nb_channels; if ((ret = check_specific_config(ctx)) < 0) { return ret;