[PATCH bpf-next 1/3] bpf: Verify BTF_KIND_LOC_PARAM vlen, flags

[Alan Maguire <alan.maguire@oracle.com>]

Ensure that vlen is at least 1, at most 8 for LOC_PARAMs
and ensure that flags are a combination of expected values.

Fixes: 33c5a3278bdb ("btf: Extend UAPI to support BTF location (inline site) info")
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
---
 kernel/bpf/btf.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 5a0179cc1676..dd7ac42649b2 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -4789,6 +4789,18 @@ static s32 btf_loc_param_check_meta(struct btf_verifier_env *env,
 		btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
 		return -EINVAL;
 	}
+	/* All LOC_PARAMs have vlen of at least 1, none have vlen > 8 */
+	if (vlen < 1 || vlen > 8) {
+		btf_verifier_log_type(env, t, "Invalid vlen");
+		return -EINVAL;
+	}
+	if (p->flags & ~(BTF_LOC_PARAM_SIGNED | BTF_LOC_PARAM_CONST |
+			 BTF_LOC_PARAM_ADDR | BTF_LOC_PARAM_REG |
+			 BTF_LOC_PARAM_DEREF | BTF_LOC_PARAM_OFFSET) ||
+	    !p->flags) {
+		btf_verifier_log_type(env, t, "Invalid flags");
+		return -EINVAL;
+	}
 
 	btf_verifier_log_type(env, t, NULL);
 
-- 
2.43.5