From 0ba719f726632d73592311615087a0d64aa2fb60 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Tue, 25 Jul 2023 02:13:10 +0200 Subject: [PATCH] avcodec/cbs_h2645: Avoid an unchecked bytesteram read The unchecked read caused the 2nd subsequent tell call to move backward resulting in a negative length Fixes: assertion failure Fixes: 60276/clusterfuzz-testcase-minimized-ffmpeg_BSF_TRACE_HEADERS_fuzzer-5434126636023808 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/cbs_h2645.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/libavcodec/cbs_h2645.c b/libavcodec/cbs_h2645.c index 34c5d1d372..21c8bc76d5 100644 --- a/libavcodec/cbs_h2645.c +++ b/libavcodec/cbs_h2645.c @@ -695,7 +695,7 @@ static int cbs_h2645_split_fragment(CodedBitstreamContext *ctx, int nal_unit_type = bytestream2_get_byte(&gbc) & 0x1f; unsigned int num_nalus = 1; if(nal_unit_type != VVC_DCI_NUT && nal_unit_type != VVC_OPI_NUT) - num_nalus = bytestream2_get_be16u(&gbc); + num_nalus = bytestream2_get_be16(&gbc); start = bytestream2_tell(&gbc); for(i = 0; i < num_nalus; i++) {