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authorLinus Torvalds <torvalds@linux-foundation.org>2019-07-08 19:02:11 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-07-08 19:02:11 -0700
commitd44a62742decca5ae5688a562584dc0fe9fc63f6 (patch)
tree4a9bb7e50652644e48e4d45fd8dcd3abac4cec41 /security/keys/keyctl.c
parentMerge tag 'selinux-pr-20190702' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux (diff)
parentkeys: Add capability-checking keyctl function (diff)
downloadlinux-dev-d44a62742decca5ae5688a562584dc0fe9fc63f6.tar.xz
linux-dev-d44a62742decca5ae5688a562584dc0fe9fc63f6.zip
Merge tag 'keys-misc-20190619' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull misc keyring updates from David Howells: "These are some miscellaneous keyrings fixes and improvements: - Fix a bunch of warnings from sparse, including missing RCU bits and kdoc-function argument mismatches - Implement a keyctl to allow a key to be moved from one keyring to another, with the option of prohibiting key replacement in the destination keyring. - Grant Link permission to possessors of request_key_auth tokens so that upcall servicing daemons can more easily arrange things such that only the necessary auth key is passed to the actual service program, and not all the auth keys a daemon might possesss. - Improvement in lookup_user_key(). - Implement a keyctl to allow keyrings subsystem capabilities to be queried. The keyutils next branch has commits to make available, document and test the move-key and capabilities code: https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/keyutils.git/log They're currently on the 'next' branch" * tag 'keys-misc-20190619' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: keys: Add capability-checking keyctl function keys: Reuse keyring_index_key::desc_len in lookup_user_key() keys: Grant Link permission to possessers of request_key auth keys keys: Add a keyctl to move a key between keyrings keys: Hoist locking out of __key_link_begin() keys: Break bits out of key_unlink() keys: Change keyring_serialise_link_sem to a mutex keys: sparse: Fix kdoc mismatches keys: sparse: Fix incorrect RCU accesses keys: sparse: Fix key_fs[ug]id_changed()
Diffstat (limited to 'security/keys/keyctl.c')
-rw-r--r--security/keys/keyctl.c90
1 files changed, 89 insertions, 1 deletions
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 5aa605ef8d9d..741e4ba382df 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -26,6 +26,18 @@
#define KEY_MAX_DESC_SIZE 4096
+static const unsigned char keyrings_capabilities[1] = {
+ [0] = (KEYCTL_CAPS0_CAPABILITIES |
+ (IS_ENABLED(CONFIG_PERSISTENT_KEYRINGS) ? KEYCTL_CAPS0_PERSISTENT_KEYRINGS : 0) |
+ (IS_ENABLED(CONFIG_KEY_DH_OPERATIONS) ? KEYCTL_CAPS0_DIFFIE_HELLMAN : 0) |
+ (IS_ENABLED(CONFIG_ASYMMETRIC_KEY_TYPE) ? KEYCTL_CAPS0_PUBLIC_KEY : 0) |
+ (IS_ENABLED(CONFIG_BIG_KEYS) ? KEYCTL_CAPS0_BIG_KEY : 0) |
+ KEYCTL_CAPS0_INVALIDATE |
+ KEYCTL_CAPS0_RESTRICT_KEYRING |
+ KEYCTL_CAPS0_MOVE
+ ),
+};
+
static int key_get_type_from_user(char *type,
const char __user *_type,
unsigned len)
@@ -569,6 +581,52 @@ 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.
@@ -1520,7 +1578,8 @@ long keyctl_session_to_parent(void)
ret = -EPERM;
oldwork = NULL;
- parent = me->real_parent;
+ parent = rcu_dereference_protected(me->real_parent,
+ lockdep_is_held(&tasklist_lock));
/* the parent mustn't be init and mustn't be a kernel thread */
if (parent->pid <= 1 || !parent->mm)
@@ -1628,6 +1687,26 @@ error:
}
/*
+ * Get keyrings subsystem capabilities.
+ */
+long keyctl_capabilities(unsigned char __user *_buffer, size_t buflen)
+{
+ size_t size = buflen;
+
+ if (size > 0) {
+ if (size > sizeof(keyrings_capabilities))
+ size = sizeof(keyrings_capabilities);
+ if (copy_to_user(_buffer, keyrings_capabilities, size) != 0)
+ return -EFAULT;
+ if (size < buflen &&
+ clear_user(_buffer + size, buflen - size) != 0)
+ return -EFAULT;
+ }
+
+ return sizeof(keyrings_capabilities);
+}
+
+/*
* The key control system call
*/
SYSCALL_DEFINE5(keyctl, int, option, unsigned long, arg2, unsigned long, arg3,
@@ -1767,6 +1846,15 @@ 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);
+
+ case KEYCTL_CAPABILITIES:
+ return keyctl_capabilities((unsigned char __user *)arg2, (size_t)arg3);
+
default:
return -EOPNOTSUPP;
}