Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Roberto Sassu <roberto.sassu@huaweicloud.com>
To:     ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org,
        martin.lau@linux.dev, song@kernel.org, yhs@fb.com,
        john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com,
        haoluo@google.com, jolsa@kernel.org, mykolal@fb.com,
        corbet@lwn.net, dhowells@redhat.com, jarkko@kernel.org,
        rostedt@goodmis.org, mingo@redhat.com, paul@paul-moore.com,
        jmorris@namei.org, serge@hallyn.com, shuah@kernel.org
Cc:     bpf@vger.kernel.org, linux-doc@vger.kernel.org,
        keyrings@vger.kernel.org, linux-security-module@vger.kernel.org,
        linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org,
        deso@posteo.net, Roberto Sassu <roberto.sassu@huawei.com>
Subject: [PATCH v14 04/10] KEYS: Move KEY_LOOKUP_ to include/linux/key.h and add flags check function
Date:   Fri, 26 Aug 2022 11:12:28 +0200
Message-Id: <20220826091228.1701185-1-roberto.sassu@huaweicloud.com>
In-Reply-To: <acae432697e854748d9a44c732ec8cab807d9d46.camel@huaweicloud.com>
References: <acae432697e854748d9a44c732ec8cab807d9d46.camel@huaweicloud.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Roberto Sassu <roberto.sassu@huawei.com>

In preparation for the patch that introduces the bpf_lookup_user_key() eBPF
kfunc, move KEY_LOOKUP_ definitions to include/linux/key.h, to be able to
validate the kfunc parameters.

Also, introduce key_lookup_flags_valid() to check if the caller set in the
argument only defined flags. Introduce it directly in include/linux/key.h,
to reduce the risk that the check is not in sync with currently defined
flags.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: KP Singh <kpsingh@kernel.org>
---
 include/linux/key.h      | 16 ++++++++++++++++
 security/keys/internal.h |  2 --
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/include/linux/key.h b/include/linux/key.h
index 7febc4881363..e679dbf0c940 100644
--- a/include/linux/key.h
+++ b/include/linux/key.h
@@ -88,6 +88,22 @@ enum key_need_perm {
 	KEY_DEFER_PERM_CHECK,	/* Special: permission check is deferred */
 };
 
+#define KEY_LOOKUP_CREATE	0x01
+#define KEY_LOOKUP_PARTIAL	0x02
+
+/**
+ * key_lookup_flags_valid - detect if provided key lookup flags are valid
+ * @flags: key lookup flags.
+ *
+ * Verify whether or not the caller set in the argument only defined flags.
+ *
+ * Return: true if flags are valid, false if not.
+ */
+static inline bool key_lookup_flags_valid(u64 flags)
+{
+	return !(flags & ~(KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL));
+}
+
 struct seq_file;
 struct user_struct;
 struct signal_struct;
diff --git a/security/keys/internal.h b/security/keys/internal.h
index 9b9cf3b6fcbb..3c1e7122076b 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -165,8 +165,6 @@ extern struct key *request_key_and_link(struct key_type *type,
 
 extern bool lookup_user_key_possessed(const struct key *key,
 				      const struct key_match_data *match_data);
-#define KEY_LOOKUP_CREATE	0x01
-#define KEY_LOOKUP_PARTIAL	0x02
 
 extern long join_session_keyring(const char *name);
 extern void key_change_session_keyring(struct callback_head *twork);
-- 
2.25.1