KEYS: Fix some sparse warnings

Fix some sparse warnings in the keyrings code:

 (1) compat_keyctl_instantiate_key_iov() should be static.

 (2) There were a couple of places where a pointer was being compared against
     integer 0 rather than NULL.

 (3) keyctl_instantiate_key_common() should not take a __user-labelled iovec
     pointer as the caller must have copied the iovec to kernel space.

 (4) __key_link_begin() takes and __key_link_end() releases
     keyring_serialise_link_sem under some circumstances and so this should be
     declared.

     Note that adding __acquires() and __releases() for this doesn't help cure
     the warnings messages - something only commenting out both helps.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>

4 files changed, 6 insertions, 4 deletions

diff --git a/security/keys/compat.c b/security/keys/compat.c
index fab4f8dda6c6..e35ae1d208a8 100644
--- a/security/keys/compat.c
+++ b/security/keys/compat.c
@@ -24,7 +24,7 @@
  *
  * If successful, 0 will be returned.
  */
-long compat_keyctl_instantiate_key_iov(
+static long compat_keyctl_instantiate_key_iov(
         key_serial_t id,
         const struct compat_iovec __user *_payload_iov,
         unsigned ioc,
@@ -33,7 +33,7 @@ long compat_keyctl_instantiate_key_iov(
         struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
         long ret;
 
-        if (_payload_iov == 0 || ioc == 0)
+        if (!_payload_iov || !ioc)
                 goto no_payload;
 
         ret = compat_rw_copy_check_uvector(WRITE, _payload_iov, ioc,
diff --git a/security/keys/internal.h b/security/keys/internal.h
index f711b094ed41..f173be2ce3ea 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -240,7 +240,7 @@ extern long keyctl_instantiate_key_iov(key_serial_t,
 extern long keyctl_invalidate_key(key_serial_t);
 
 extern long keyctl_instantiate_key_common(key_serial_t,
-                                          const struct iovec __user *,
+                                          const struct iovec *,
                                           unsigned, size_t, key_serial_t);
 
 /*
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index ddb3e05bc5fc..b61c063888b9 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -1106,7 +1106,7 @@ long keyctl_instantiate_key_iov(key_serial_t id,
         struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
         long ret;
 
-        if (_payload_iov == 0 || ioc == 0)
+        if (!_payload_iov || !ioc)
                 goto no_payload;
 
         ret = rw_copy_check_uvector(WRITE, _payload_iov, ioc,
diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index 7445875f6818..81e7852d281d 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -751,6 +751,7 @@ static void keyring_unlink_rcu_disposal(struct rcu_head *rcu)
 int __key_link_begin(struct key *keyring, const struct key_type *type,
                      const char *description, unsigned long *_prealloc)
         __acquires(&keyring->sem)
+        __acquires(&keyring_serialise_link_sem)
 {
         struct keyring_list *klist, *nklist;
         unsigned long prealloc;
@@ -960,6 +961,7 @@ void __key_link(struct key *keyring, struct key *key,
 void __key_link_end(struct key *keyring, struct key_type *type,
                     unsigned long prealloc)
         __releases(&keyring->sem)
+        __releases(&keyring_serialise_link_sem)
 {
         BUG_ON(type == NULL);
         BUG_ON(type->name == NULL);