[PATCH 5.5 142/170] bpf/btf: Fix BTF verification of enum members in struct/union

[Greg Kroah-Hartman]

From: Yoshiki Komachi <komachi.yoshiki@xxxxxxxxx>

commit da6c7faeb103c493e505e87643272f70be586635 upstream.

btf_enum_check_member() was currently sure to recognize the size of
"enum" type members in struct/union as the size of "int" even if
its size was packed.

This patch fixes BTF enum verification to use the correct size
of member in BPF programs.

Fixes: 179cde8cef7e ("bpf: btf: Check members of struct/union")
Signed-off-by: Yoshiki Komachi <komachi.yoshiki@xxxxxxxxx>
Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
Link: https://lore.kernel.org/bpf/1583825550-18606-2-git-send-email-komachi.yoshiki@xxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 kernel/bpf/btf.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -2383,7 +2383,7 @@ static int btf_enum_check_member(struct
 
 	struct_size = struct_type->size;
 	bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
-	if (struct_size - bytes_offset < sizeof(int)) {
+	if (struct_size - bytes_offset < member_type->size) {
 		btf_verifier_log_member(env, struct_type, member,
 					"Member exceeds struct_size");
 		return -EINVAL;