bpf/btf: Fix BTF verification of enum members in struct/union

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@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/1583825550-18606-2-git-send-email-komachi.yoshiki@gmail.com

diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 7871400..32ab922 100644 (file)
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -2418,7 +2418,7 @@ static int btf_enum_check_member(struct btf_verifier_env *env,
 
        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;