From: Tony Ambardar <tony.ambardar@xxxxxxxxx> Update btf_ext_parse_info() to ensure the core_relo header is present before reading its fields. This avoids a potential buffer read overflow reported by the OSS Fuzz project. Fixes: cf579164e9ea ("libbpf: Support BTF.ext loading and output in either endianness") Link: https://issues.oss-fuzz.com/issues/388905046 Signed-off-by: Tony Ambardar <tony.ambardar@xxxxxxxxx> --- tools/lib/bpf/btf.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index 48c66f3a9200..560b519f820e 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -3015,8 +3015,6 @@ static int btf_ext_parse_info(struct btf_ext *btf_ext, bool is_native) .desc = "line_info", }; struct btf_ext_sec_info_param core_relo = { - .off = btf_ext->hdr->core_relo_off, - .len = btf_ext->hdr->core_relo_len, .min_rec_size = sizeof(struct bpf_core_relo), .ext_info = &btf_ext->core_relo_info, .desc = "core_relo", @@ -3034,6 +3032,8 @@ static int btf_ext_parse_info(struct btf_ext *btf_ext, bool is_native) if (btf_ext->hdr->hdr_len < offsetofend(struct btf_ext_header, core_relo_len)) return 0; /* skip core relos parsing */ + core_relo.off = btf_ext->hdr->core_relo_off; + core_relo.len = btf_ext->hdr->core_relo_len; err = btf_ext_parse_sec_info(btf_ext, &core_relo, is_native); if (err) return err; -- 2.34.1