Subject: [PATCH bpf 1/2] bpf: fix BTF verification of enums

From: Alexei Starovoitov <[email-masked]>
Date: Tue, 17 Sep 2019 10:45:37 -0700

vmlinux BTF has enums that are 8 byte and 1 byte in size.
2 byte enum is a valid construct as well.
Fix BTF enum verification to accept those sizes.

Fixes: 69b693f0aefa ("bpf: btf: Introduce BPF Type Format (BTF)")
Signed-off-by: Alexei Starovoitov <[email-masked]>
Acked-by: Martin KaFai Lau <[email-masked]>
---
 kernel/bpf/btf.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index adb3adcebe3c..722d38e543e9 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -2377,9 +2377,8 @@ static s32 btf_enum_check_meta(struct btf_verifier_env *env,
 		return -EINVAL;
 	}
 
-	if (t->size != sizeof(int)) {
-		btf_verifier_log_type(env, t, "Expected size:%zu",
-				      sizeof(int));
+	if (t->size > 8 || !is_power_of_2(t->size)) {
+		btf_verifier_log_type(env, t, "Unexpected size");
 		return -EINVAL;
 	}
 
-- 
2.20.0