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authorDavid Howells <dhowells@redhat.com>2019-05-20 21:51:50 +0100
committerDavid Howells <dhowells@redhat.com>2019-05-30 22:44:48 +0100
commited0ac5c7ec3763e3261c48e3c5d4b7528b60fd85 (patch)
tree865eac3b9b967b974e23190e4e8bccab8f2b87bf /security/keys/keyctl.c
parentkeys: Hoist locking out of __key_link_begin() (diff)
downloadlinux-dev-ed0ac5c7ec3763e3261c48e3c5d4b7528b60fd85.tar.xz
linux-dev-ed0ac5c7ec3763e3261c48e3c5d4b7528b60fd85.zip
keys: Add a keyctl to move a key between keyrings
Add a keyctl to atomically move a link to a key from one keyring to another. The key must exist in "from" keyring and a flag can be given to cause the operation to fail if there's a matching key already in the "to" keyring. This can be done with: keyctl(KEYCTL_MOVE, key_serial_t key, key_serial_t from_keyring, key_serial_t to_keyring, unsigned int flags); The key being moved must grant Link permission and both keyrings must grant Write permission. flags should be 0 or KEYCTL_MOVE_EXCL, with the latter preventing displacement of a matching key from the "to" keyring. Signed-off-by: David Howells <dhowells@redhat.com>
Diffstat (limited to '')
-rw-r--r--security/keys/keyctl.c52
1 files changed, 52 insertions, 0 deletions
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 0f947bcbad46..bbfe7d92d41c 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -573,6 +573,52 @@ error:
}
/*
+ * Move a link to a key from one keyring to another, displacing any matching
+ * key from the destination keyring.
+ *
+ * The key must grant the caller Link permission and both keyrings must grant
+ * the caller Write permission. There must also be a link in the from keyring
+ * to the key. If both keyrings are the same, nothing is done.
+ *
+ * If successful, 0 will be returned.
+ */
+long keyctl_keyring_move(key_serial_t id, key_serial_t from_ringid,
+ key_serial_t to_ringid, unsigned int flags)
+{
+ key_ref_t key_ref, from_ref, to_ref;
+ long ret;
+
+ if (flags & ~KEYCTL_MOVE_EXCL)
+ return -EINVAL;
+
+ key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE, KEY_NEED_LINK);
+ if (IS_ERR(key_ref))
+ return PTR_ERR(key_ref);
+
+ from_ref = lookup_user_key(from_ringid, 0, KEY_NEED_WRITE);
+ if (IS_ERR(from_ref)) {
+ ret = PTR_ERR(from_ref);
+ goto error2;
+ }
+
+ to_ref = lookup_user_key(to_ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE);
+ if (IS_ERR(to_ref)) {
+ ret = PTR_ERR(to_ref);
+ goto error3;
+ }
+
+ ret = key_move(key_ref_to_ptr(key_ref), key_ref_to_ptr(from_ref),
+ key_ref_to_ptr(to_ref), flags);
+
+ key_ref_put(to_ref);
+error3:
+ key_ref_put(from_ref);
+error2:
+ key_ref_put(key_ref);
+ return ret;
+}
+
+/*
* Return a description of a key to userspace.
*
* The key must grant the caller View permission for this to work.
@@ -1772,6 +1818,12 @@ SYSCALL_DEFINE5(keyctl, int, option, unsigned long, arg2, unsigned long, arg3,
(const void __user *)arg4,
(const void __user *)arg5);
+ case KEYCTL_MOVE:
+ return keyctl_keyring_move((key_serial_t)arg2,
+ (key_serial_t)arg3,
+ (key_serial_t)arg4,
+ (unsigned int)arg5);
+
default:
return -EOPNOTSUPP;
}