release/5.2.41/bpf-btf-Fix-BTF-verification-of-enum-members-in-stru.patch

From 6055703fcfee70fa3223fad4a8ee400b4f4ee94c Mon Sep 17 00:00:00 2001
From: Yoshiki Komachi <komachi.yoshiki@gmail.com>
Date: Tue, 10 Mar 2020 16:32:29 +0900
Subject: [PATCH] bpf/btf: Fix BTF verification of enum members in struct/union

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@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
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 5fcc7a17eb5a..577b7b3e7bfe 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -2309,7 +2309,7 @@ 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;
-- 
2.7.4