bpf: Prevent decl_tag from being referenced in func_proto arg

stable inclusion
from stable-v5.10.163
commit 329a76635548ee8fceb3b78c7d54d96524e80925
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I6O293

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=329a76635548ee8fceb3b78c7d54d96524e80925

--------------------------------

[ Upstream commit f17472d4 ]

Syzkaller managed to hit another decl_tag issue:

  btf_func_proto_check kernel/bpf/btf.c:4506 [inline]
  btf_check_all_types kernel/bpf/btf.c:4734 [inline]
  btf_parse_type_sec+0x1175/0x1980 kernel/bpf/btf.c:4763
  btf_parse kernel/bpf/btf.c:5042 [inline]
  btf_new_fd+0x65a/0xb00 kernel/bpf/btf.c:6709
  bpf_btf_load+0x6f/0x90 kernel/bpf/syscall.c:4342
  __sys_bpf+0x50a/0x6c0 kernel/bpf/syscall.c:5034
  __do_sys_bpf kernel/bpf/syscall.c:5093 [inline]
  __se_sys_bpf kernel/bpf/syscall.c:5091 [inline]
  __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5091
  do_syscall_64+0x54/0x70 arch/x86/entry/common.c:48

This seems similar to commit ea68376c ("bpf: prevent decl_tag from being
referenced in func_proto") but for the argument.

Reported-by: syzbot+8dd0551dda6020944c5d@syzkaller.appspotmail.com
Signed-off-by: NStanislav Fomichev <sdf@google.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NYonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20221123035422.872531-2-sdf@google.comSigned-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NPu Lehui <pulehui@huawei.com>
Reviewed-by: NXu Kuohai <xukuohai@huawei.com>
Signed-off-by: NJialin Zhang <zhangjialin11@huawei.com>

kernel/bpf/btf.c

@@ -3675,6 +3675,11 @@ static int btf_func_proto_check(struct btf_verifier_env *env,
 			break;
 		}
 
+		if (btf_type_is_resolve_source_only(arg_type)) {
+			btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
+			return -EINVAL;
+		}
+
 		if (args[i].name_off &&
 		    (!btf_name_offset_valid(btf, args[i].name_off) ||
 		     !btf_name_valid_identifier(btf, args[i].name_off))) {