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 <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
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 <ast@kernel.org>
Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>
This commit is contained in:
Tony Ambardar
2025-01-24 22:52:36 -08:00
committed by Andrii Nakryiko
parent 9544a909f1
commit 71208c3362

View File

@@ -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;