From 0c48c332eeb2866d9353125f701e099c48889463 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 31 Jan 2021 22:36:52 +0100 Subject: [PATCH] avcodec/h264_metadata_bsf: Check nb_units before accessing the first in h264_metadata_update_fragment() Fixes: null pointer dereference Fixes: 29835/clusterfuzz-testcase-minimized-ffmpeg_BSF_H264_METADATA_fuzzer-4712125383704576 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/h264_metadata_bsf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/libavcodec/h264_metadata_bsf.c b/libavcodec/h264_metadata_bsf.c index c3a63f3578..6e58c0be1d 100644 --- a/libavcodec/h264_metadata_bsf.c +++ b/libavcodec/h264_metadata_bsf.c @@ -462,7 +462,7 @@ static int h264_metadata_update_fragment(AVBSFContext *bsf, AVPacket *pkt, int err, i, has_sps, seek_point; // If an AUD is present, it must be the first NAL unit. - if (au->units[0].type == H264_NAL_AUD) { + if (au->nb_units && au->units[0].type == H264_NAL_AUD) { if (ctx->aud == BSF_ELEMENT_REMOVE) ff_cbs_delete_unit(au, 0); } else {