diff mbox series

[v14,04/10] KEYS: Move KEY_LOOKUP_ to include/linux/key.h and add flags check function

Message ID 20220826091228.1701185-1-roberto.sassu@huaweicloud.com
State New
Headers show
Series None | expand

Commit Message

Roberto Sassu Aug. 26, 2022, 9:12 a.m. UTC 
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(-)

Comments

Jarkko Sakkinen Aug. 28, 2022, 4:03 a.m. UTC | #1 
On Sun, Aug 28, 2022 at 06:59:41AM +0300, Jarkko Sakkinen wrote:
> On Fri, Aug 26, 2022 at 11:22:54AM +0200, Roberto Sassu wrote:
> > On Fri, 2022-08-26 at 11:12 +0200, Roberto Sassu wrote:
> > > 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>
> > 
> > Jarkko, could you please ack it if it is fine?
> 
> So, as said I'm not really confident that a function is
> even needed in the first place. It's fine if there are
> enough call sites to make it legit.

And *if* a named constant is enough, you could probably
then just squash to the same patch that uses it, right?

If there overwhelming amount of call sites I do fully
get having a helper.

BR, Jarkko
diff mbox series

Patch

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);