From: Tony Ambardar Date: Sat, 25 Jan 2025 06:52:36 +0000 (-0800) Subject: libbpf: Fix accessing BTF.ext core_relo header X-Git-Tag: v6.15-rc1~98^2~92 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=0a7c2a84359612e54328aa52030eb202093da6e2;p=thirdparty%2Fkernel%2Flinux.git libbpf: Fix accessing BTF.ext core_relo header 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") Signed-off-by: Tony Ambardar Signed-off-by: Andrii Nakryiko Link: https://issues.oss-fuzz.com/issues/388905046 Link: https://lore.kernel.org/bpf/20250125065236.2603346-1-itugrok@yahoo.com Signed-off-by: Alexei Starovoitov --- diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index 48c66f3a92002..560b519f820e2 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;