KEYS: Move the flags representing required permission to linux/key.h

Move the flags representing required permission to linux/key.h as the perm
parameter of security_key_permission() is in terms of them - and not the
permissions mask flags used in key->perm.

Whilst we're at it:

 (1) Rename them to be KEY_NEED_xxx rather than KEY_xxx to avoid collisions
     with symbols in uapi/linux/input.h.

 (2) Don't use key_perm_t for a mask of required permissions, but rather limit
     it to the permissions mask attached to the key and arguments related
     directly to that.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Dmitry Kasatkin <d.kasatkin@samsung.com>

13 files changed, 53 insertions, 51 deletions

diff --git a/include/linux/key.h b/include/linux/key.h
index 80d677483e31..cd0abb8c9c33 100644
--- a/include/linux/key.h
+++ b/include/linux/key.h
@@ -309,6 +309,17 @@ static inline key_serial_t key_serial(const struct key *key)
 
 extern void key_set_timeout(struct key *, unsigned);
 
+/*
+ * The permissions required on a key that we're looking up.
+ */
+#define	KEY_NEED_VIEW	0x01	/* Require permission to view attributes */
+#define	KEY_NEED_READ	0x02	/* Require permission to read content */
+#define	KEY_NEED_WRITE	0x04	/* Require permission to update / modify */
+#define	KEY_NEED_SEARCH	0x08	/* Require permission to search (keyring) or find (key) */
+#define	KEY_NEED_LINK	0x10	/* Require permission to link */
+#define	KEY_NEED_SETATTR 0x20	/* Require permission to change attributes */
+#define	KEY_NEED_ALL	0x3f	/* All the above permissions */
+
 /**
  * key_is_instantiated - Determine if a key has been positively instantiated
  * @key: The key to check.
diff --git a/include/linux/security.h b/include/linux/security.h
index 5623a7f965b7..3a5ed0cd2751 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1707,7 +1707,7 @@ struct security_operations {
 	void (*key_free) (struct key *key);
 	int (*key_permission) (key_ref_t key_ref,
 			       const struct cred *cred,
-			       key_perm_t perm);
+			       unsigned perm);
 	int (*key_getsecurity)(struct key *key, char **_buffer);
 #endif	/* CONFIG_KEYS */
 
@@ -3026,7 +3026,7 @@ static inline int security_path_chroot(struct path *path)
 int security_key_alloc(struct key *key, const struct cred *cred, unsigned long flags);
 void security_key_free(struct key *key);
 int security_key_permission(key_ref_t key_ref,
-			    const struct cred *cred, key_perm_t perm);
+			    const struct cred *cred, unsigned perm);
 int security_key_getsecurity(struct key *key, char **_buffer);
 
 #else
@@ -3044,7 +3044,7 @@ static inline void security_key_free(struct key *key)
 
 static inline int security_key_permission(key_ref_t key_ref,
 					  const struct cred *cred,
-					  key_perm_t perm)
+					  unsigned perm)
 {
 	return 0;
 }
diff --git a/security/capability.c b/security/capability.c
index 8b4f24ae4338..c1426b91f4bd 100644
--- a/security/capability.c
+++ b/security/capability.c
@@ -878,7 +878,7 @@ static void cap_key_free(struct key *key)
 }
 
 static int cap_key_permission(key_ref_t key_ref, const struct cred *cred,
-			      key_perm_t perm)
+			      unsigned perm)
 {
 	return 0;
 }
diff --git a/security/keys/internal.h b/security/keys/internal.h
index 80b2aac4f50c..5f20da01fd8d 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -176,20 +176,11 @@ extern int key_task_permission(const key_ref_t key_ref,
 /*
  * Check to see whether permission is granted to use a key in the desired way.
  */
-static inline int key_permission(const key_ref_t key_ref, key_perm_t perm)
+static inline int key_permission(const key_ref_t key_ref, unsigned perm)
 {
 	return key_task_permission(key_ref, current_cred(), perm);
 }
 
-/* required permissions */
-#define	KEY_VIEW	0x01	/* require permission to view attributes */
-#define	KEY_READ	0x02	/* require permission to read content */
-#define	KEY_WRITE	0x04	/* require permission to update / modify */
-#define	KEY_SEARCH	0x08	/* require permission to search (keyring) or find (key) */
-#define	KEY_LINK	0x10	/* require permission to link */
-#define	KEY_SETATTR	0x20	/* require permission to change attributes */
-#define	KEY_ALL		0x3f	/* all the above permissions */
-
 /*
  * Authorisation record for request_key().
  */
diff --git a/security/keys/key.c b/security/keys/key.c
index 6e21c11e48bc..2048a110e7f1 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -714,7 +714,7 @@ static inline key_ref_t __key_update(key_ref_t key_ref,
 	int ret;
 
 	/* need write permission on the key to update it */
-	ret = key_permission(key_ref, KEY_WRITE);
+	ret = key_permission(key_ref, KEY_NEED_WRITE);
 	if (ret < 0)
 		goto error;
 
@@ -838,7 +838,7 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
 
 	/* if we're going to allocate a new key, we're going to have
 	 * to modify the keyring */
-	ret = key_permission(keyring_ref, KEY_WRITE);
+	ret = key_permission(keyring_ref, KEY_NEED_WRITE);
 	if (ret < 0) {
 		key_ref = ERR_PTR(ret);
 		goto error_link_end;
@@ -928,7 +928,7 @@ int key_update(key_ref_t key_ref, const void *payload, size_t plen)
 	key_check(key);
 
 	/* the key must be writable */
-	ret = key_permission(key_ref, KEY_WRITE);
+	ret = key_permission(key_ref, KEY_NEED_WRITE);
 	if (ret < 0)
 		goto error;
 
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index cee72ce64222..cd5bd0cef25d 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -111,7 +111,7 @@ SYSCALL_DEFINE5(add_key, const char __user *, _type,
 	}
 
 	/* find the target keyring (which must be writable) */
-	keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
+	keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE);
 	if (IS_ERR(keyring_ref)) {
 		ret = PTR_ERR(keyring_ref);
 		goto error3;
@@ -195,7 +195,7 @@ SYSCALL_DEFINE4(request_key, const char __user *, _type,
 	dest_ref = NULL;
 	if (destringid) {
 		dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE,
-					   KEY_WRITE);
+					   KEY_NEED_WRITE);
 		if (IS_ERR(dest_ref)) {
 			ret = PTR_ERR(dest_ref);
 			goto error3;
@@ -253,7 +253,7 @@ long keyctl_get_keyring_ID(key_serial_t id, int create)
 	long ret;
 
 	lflags = create ? KEY_LOOKUP_CREATE : 0;
-	key_ref = lookup_user_key(id, lflags, KEY_SEARCH);
+	key_ref = lookup_user_key(id, lflags, KEY_NEED_SEARCH);
 	if (IS_ERR(key_ref)) {
 		ret = PTR_ERR(key_ref);
 		goto error;
@@ -334,7 +334,7 @@ long keyctl_update_key(key_serial_t id,
 	}
 
 	/* find the target key (which must be writable) */
-	key_ref = lookup_user_key(id, 0, KEY_WRITE);
+	key_ref = lookup_user_key(id, 0, KEY_NEED_WRITE);
 	if (IS_ERR(key_ref)) {
 		ret = PTR_ERR(key_ref);
 		goto error2;
@@ -365,12 +365,12 @@ long keyctl_revoke_key(key_serial_t id)
 	key_ref_t key_ref;
 	long ret;
 
-	key_ref = lookup_user_key(id, 0, KEY_WRITE);
+	key_ref = lookup_user_key(id, 0, KEY_NEED_WRITE);
 	if (IS_ERR(key_ref)) {
 		ret = PTR_ERR(key_ref);
 		if (ret != -EACCES)
 			goto error;
-		key_ref = lookup_user_key(id, 0, KEY_SETATTR);
+		key_ref = lookup_user_key(id, 0, KEY_NEED_SETATTR);
 		if (IS_ERR(key_ref)) {
 			ret = PTR_ERR(key_ref);
 			goto error;
@@ -401,7 +401,7 @@ long keyctl_invalidate_key(key_serial_t id)
 
 	kenter("%d", id);
 
-	key_ref = lookup_user_key(id, 0, KEY_SEARCH);
+	key_ref = lookup_user_key(id, 0, KEY_NEED_SEARCH);
 	if (IS_ERR(key_ref)) {
 		ret = PTR_ERR(key_ref);
 		goto error;
@@ -428,7 +428,7 @@ long keyctl_keyring_clear(key_serial_t ringid)
 	key_ref_t keyring_ref;
 	long ret;
 
-	keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
+	keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE);
 	if (IS_ERR(keyring_ref)) {
 		ret = PTR_ERR(keyring_ref);
 
@@ -470,13 +470,13 @@ long keyctl_keyring_link(key_serial_t id, key_serial_t ringid)
 	key_ref_t keyring_ref, key_ref;
 	long ret;
 
-	keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
+	keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE);
 	if (IS_ERR(keyring_ref)) {
 		ret = PTR_ERR(keyring_ref);
 		goto error;
 	}
 
-	key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE, KEY_LINK);
+	key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE, KEY_NEED_LINK);
 	if (IS_ERR(key_ref)) {
 		ret = PTR_ERR(key_ref);
 		goto error2;
@@ -505,7 +505,7 @@ long keyctl_keyring_unlink(key_serial_t id, key_serial_t ringid)
 	key_ref_t keyring_ref, key_ref;
 	long ret;
 
-	keyring_ref = lookup_user_key(ringid, 0, KEY_WRITE);
+	keyring_ref = lookup_user_key(ringid, 0, KEY_NEED_WRITE);
 	if (IS_ERR(keyring_ref)) {
 		ret = PTR_ERR(keyring_ref);
 		goto error;
@@ -548,7 +548,7 @@ long keyctl_describe_key(key_serial_t keyid,
 	char *tmpbuf;
 	long ret;
 
-	key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_VIEW);
+	key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_NEED_VIEW);
 	if (IS_ERR(key_ref)) {
 		/* viewing a key under construction is permitted if we have the
 		 * authorisation token handy */
@@ -639,7 +639,7 @@ long keyctl_keyring_search(key_serial_t ringid,
 	}
 
 	/* get the keyring at which to begin the search */
-	keyring_ref = lookup_user_key(ringid, 0, KEY_SEARCH);
+	keyring_ref = lookup_user_key(ringid, 0, KEY_NEED_SEARCH);
 	if (IS_ERR(keyring_ref)) {
 		ret = PTR_ERR(keyring_ref);
 		goto error2;
@@ -649,7 +649,7 @@ long keyctl_keyring_search(key_serial_t ringid,
 	dest_ref = NULL;
 	if (destringid) {
 		dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE,
-					   KEY_WRITE);
+					   KEY_NEED_WRITE);
 		if (IS_ERR(dest_ref)) {
 			ret = PTR_ERR(dest_ref);
 			goto error3;
@@ -676,7 +676,7 @@ long keyctl_keyring_search(key_serial_t ringid,
 
 	/* link the resulting key to the destination keyring if we can */
 	if (dest_ref) {
-		ret = key_permission(key_ref, KEY_LINK);
+		ret = key_permission(key_ref, KEY_NEED_LINK);
 		if (ret < 0)
 			goto error6;
 
@@ -727,7 +727,7 @@ long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen)
 	key = key_ref_to_ptr(key_ref);
 
 	/* see if we can read it directly */
-	ret = key_permission(key_ref, KEY_READ);
+	ret = key_permission(key_ref, KEY_NEED_READ);
 	if (ret == 0)
 		goto can_read_key;
 	if (ret != -EACCES)
@@ -799,7 +799,7 @@ long keyctl_chown_key(key_serial_t id, uid_t user, gid_t group)
 		goto error;
 
 	key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
-				  KEY_SETATTR);
+				  KEY_NEED_SETATTR);
 	if (IS_ERR(key_ref)) {
 		ret = PTR_ERR(key_ref);
 		goto error;
@@ -905,7 +905,7 @@ long keyctl_setperm_key(key_serial_t id, key_perm_t perm)
 		goto error;
 
 	key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
-				  KEY_SETATTR);
+				  KEY_NEED_SETATTR);
 	if (IS_ERR(key_ref)) {
 		ret = PTR_ERR(key_ref);
 		goto error;
@@ -947,7 +947,7 @@ static long get_instantiation_keyring(key_serial_t ringid,
 
 	/* if a specific keyring is nominated by ID, then use that */
 	if (ringid > 0) {
-		dkref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
+		dkref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE);
 		if (IS_ERR(dkref))
 			return PTR_ERR(dkref);
 		*_dest_keyring = key_ref_to_ptr(dkref);
@@ -1315,7 +1315,7 @@ long keyctl_set_timeout(key_serial_t id, unsigned timeout)
 	long ret;
 
 	key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
-				  KEY_SETATTR);
+				  KEY_NEED_SETATTR);
 	if (IS_ERR(key_ref)) {
 		/* setting the timeout on a key under construction is permitted
 		 * if we have the authorisation token handy */
@@ -1418,7 +1418,7 @@ long keyctl_get_security(key_serial_t keyid,
 	char *context;
 	long ret;
 
-	key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_VIEW);
+	key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_NEED_VIEW);
 	if (IS_ERR(key_ref)) {
 		if (PTR_ERR(key_ref) != -EACCES)
 			return PTR_ERR(key_ref);
@@ -1482,7 +1482,7 @@ long keyctl_session_to_parent(void)
 	struct cred *cred;
 	int ret;
 
-	keyring_r = lookup_user_key(KEY_SPEC_SESSION_KEYRING, 0, KEY_LINK);
+	keyring_r = lookup_user_key(KEY_SPEC_SESSION_KEYRING, 0, KEY_NEED_LINK);
 	if (IS_ERR(keyring_r))
 		return PTR_ERR(keyring_r);
 
diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index 2fb2576dc644..9cf2575f0d97 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -541,7 +541,7 @@ static int keyring_search_iterator(const void *object, void *iterator_data)
 	/* key must have search permissions */
 	if (!(ctx->flags & KEYRING_SEARCH_NO_CHECK_PERM) &&
 	    key_task_permission(make_key_ref(key, ctx->possessed),
-				ctx->cred, KEY_SEARCH) < 0) {
+				ctx->cred, KEY_NEED_SEARCH) < 0) {
 		ctx->result = ERR_PTR(-EACCES);
 		kleave(" = %d [!perm]", ctx->skipped_ret);
 		goto skipped;
@@ -721,7 +721,7 @@ ascend_to_node:
 		/* Search a nested keyring */
 		if (!(ctx->flags & KEYRING_SEARCH_NO_CHECK_PERM) &&
 		    key_task_permission(make_key_ref(key, ctx->possessed),
-					ctx->cred, KEY_SEARCH) < 0)
+					ctx->cred, KEY_NEED_SEARCH) < 0)
 			continue;
 
 		/* stack the current position */
@@ -843,7 +843,7 @@ key_ref_t keyring_search_aux(key_ref_t keyring_ref,
 		return ERR_PTR(-ENOTDIR);
 
 	if (!(ctx->flags & KEYRING_SEARCH_NO_CHECK_PERM)) {
-		err = key_task_permission(keyring_ref, ctx->cred, KEY_SEARCH);
+		err = key_task_permission(keyring_ref, ctx->cred, KEY_NEED_SEARCH);
 		if (err < 0)
 			return ERR_PTR(err);
 	}
@@ -973,7 +973,7 @@ struct key *find_keyring_by_name(const char *name, bool skip_perm_check)
 
 			if (!skip_perm_check &&
 			    key_permission(make_key_ref(keyring, 0),
-					   KEY_SEARCH) < 0)
+					   KEY_NEED_SEARCH) < 0)
 				continue;
 
 			/* we've got a match but we might end up racing with
diff --git a/security/keys/permission.c b/security/keys/permission.c
index efcc0c855a0d..732cc0beffdf 100644
--- a/security/keys/permission.c
+++ b/security/keys/permission.c
@@ -28,7 +28,7 @@
  * permissions bits or the LSM check.
  */
 int key_task_permission(const key_ref_t key_ref, const struct cred *cred,
-			key_perm_t perm)
+			unsigned perm)
 {
 	struct key *key;
 	key_perm_t kperm;
@@ -68,7 +68,7 @@ use_these_perms:
 	if (is_key_possessed(key_ref))
 		kperm |= key->perm >> 24;
 
-	kperm = kperm & perm & KEY_ALL;
+	kperm = kperm & perm & KEY_NEED_ALL;
 
 	if (kperm != perm)
 		return -EACCES;
diff --git a/security/keys/persistent.c b/security/keys/persistent.c
index 0ad3ee283781..c9fae5ea89fe 100644
--- a/security/keys/persistent.c
+++ b/security/keys/persistent.c
@@ -108,7 +108,7 @@ static long key_get_persistent(struct user_namespace *ns, kuid_t uid,
 	return PTR_ERR(persistent_ref);
 
 found:
-	ret = key_task_permission(persistent_ref, current_cred(), KEY_LINK);
+	ret = key_task_permission(persistent_ref, current_cred(), KEY_NEED_LINK);
 	if (ret == 0) {
 		persistent = key_ref_to_ptr(persistent_ref);
 		ret = key_link(key_ref_to_ptr(dest_ref), persistent);
@@ -151,7 +151,7 @@ long keyctl_get_persistent(uid_t _uid, key_serial_t destid)
 	}
 
 	/* There must be a destination keyring */
-	dest_ref = lookup_user_key(destid, KEY_LOOKUP_CREATE, KEY_WRITE);
+	dest_ref = lookup_user_key(destid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE);
 	if (IS_ERR(dest_ref))
 		return PTR_ERR(dest_ref);
 	if (key_ref_to_ptr(dest_ref)->type != &key_type_keyring) {
diff --git a/security/keys/proc.c b/security/keys/proc.c
index 88e9a466940f..d3f6f2fd21db 100644
--- a/security/keys/proc.c
+++ b/security/keys/proc.c
@@ -218,7 +218,7 @@ static int proc_keys_show(struct seq_file *m, void *v)
 	 * - the caller holds a spinlock, and thus the RCU read lock, making our
 	 *   access to __current_cred() safe
 	 */
-	rc = key_task_permission(key_ref, ctx.cred, KEY_VIEW);
+	rc = key_task_permission(key_ref, ctx.cred, KEY_NEED_VIEW);
 	if (rc < 0)
 		return 0;
 
diff --git a/security/security.c b/security/security.c
index 15b6928592ef..8e428ac90233 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1405,7 +1405,7 @@ void security_key_free(struct key *key)
 }
 
 int security_key_permission(key_ref_t key_ref,
-			    const struct cred *cred, key_perm_t perm)
+			    const struct cred *cred, unsigned perm)
 {
 	return security_ops->key_permission(key_ref, cred, perm);
 }
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 4b34847208cc..eb5c307fcc9a 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -5704,7 +5704,7 @@ static void selinux_key_free(struct key *k)
 
 static int selinux_key_permission(key_ref_t key_ref,
 				  const struct cred *cred,
-				  key_perm_t perm)
+				  unsigned perm)
 {
 	struct key *key;
 	struct key_security_struct *ksec;
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 14f52be78c75..c47dd8ca019c 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3506,7 +3506,7 @@ static void smack_key_free(struct key *key)
  * an error code otherwise
  */
 static int smack_key_permission(key_ref_t key_ref,
-				const struct cred *cred, key_perm_t perm)
+				const struct cred *cred, unsigned perm)
 {
 	struct key *keyp;
 	struct smk_audit_info ad;