LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: David Howells <dhowells@redhat.com>
To: keyrings@vger.kernel.org
Cc: dhowells@redhat.com, linux-security-module@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH 4/7] keys: Break bits out of key_unlink()
Date: Wed, 22 May 2019 23:28:31 +0100	[thread overview]
Message-ID: <155856411142.10428.16280282329908085391.stgit@warthog.procyon.org.uk> (raw)
In-Reply-To: <155856408314.10428.17035328117829912815.stgit@warthog.procyon.org.uk>

Break bits out of key_unlink() into helper functions so that they can be
used in implementing key_move().

Signed-off-by: David Howells <dhowells@redhat.com>
---

 security/keys/keyring.c |   86 ++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 65 insertions(+), 21 deletions(-)

diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index 5b218b270598..2cfeeeaa1ffa 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -1382,6 +1382,65 @@ int key_link(struct key *keyring, struct key *key)
 }
 EXPORT_SYMBOL(key_link);
 
+/*
+ * Begin the process of unlinking a key from a keyring.
+ */
+static int __key_unlink_begin(struct key *keyring, unsigned int lock_nesting,
+			      struct key *key, struct assoc_array_edit **_edit)
+	__acquires(&keyring->sem)
+{
+	struct assoc_array_edit *edit;
+	int ret;
+
+	if (keyring->type != &key_type_keyring)
+		return -ENOTDIR;
+
+	down_write_nested(&keyring->sem, lock_nesting);
+
+	edit = assoc_array_delete(&keyring->keys, &keyring_assoc_array_ops,
+				  &key->index_key);
+	if (IS_ERR(edit)) {
+		ret = PTR_ERR(edit);
+		goto error;
+	}
+
+	if (!edit) {
+		ret = -ENOENT;
+		goto error;
+	}
+
+	*_edit = edit;
+	return 0;
+
+error:
+	up_write(&keyring->sem);
+	return ret;
+}
+
+/*
+ * Apply an unlink change.
+ */
+static void __key_unlink(struct key *keyring, struct key *key,
+			      struct assoc_array_edit **_edit)
+{
+	assoc_array_apply_edit(*_edit);
+	*_edit = NULL;
+	key_payload_reserve(keyring, keyring->datalen - KEYQUOTA_LINK_BYTES);
+}
+
+/*
+ * Finish unlinking a key from to a keyring.
+ */
+static void __key_unlink_end(struct key *keyring,
+			     struct key *key,
+			     struct assoc_array_edit *edit)
+	__releases(&keyring->sem)
+{
+	if (edit)
+		assoc_array_cancel_edit(edit);
+	up_write(&keyring->sem);
+}
+
 /**
  * key_unlink - Unlink the first link to a key from a keyring.
  * @keyring: The keyring to remove the link from.
@@ -1407,28 +1466,13 @@ int key_unlink(struct key *keyring, struct key *key)
 	key_check(keyring);
 	key_check(key);
 
-	if (keyring->type != &key_type_keyring)
-		return -ENOTDIR;
-
-	down_write(&keyring->sem);
-
-	edit = assoc_array_delete(&keyring->keys, &keyring_assoc_array_ops,
-				  &key->index_key);
-	if (IS_ERR(edit)) {
-		ret = PTR_ERR(edit);
-		goto error;
-	}
-	ret = -ENOENT;
-	if (edit == NULL)
-		goto error;
-
-	assoc_array_apply_edit(edit);
-	key_payload_reserve(keyring, keyring->datalen - KEYQUOTA_LINK_BYTES);
-	ret = 0;
+	ret = __key_unlink_begin(keyring, 0, key, &edit);
+	if (ret < 0)
+		return ret;
 
-error:
-	up_write(&keyring->sem);
-	return ret;
+	__key_unlink(keyring, key, &edit);
+	__key_unlink_end(keyring, key, edit);
+	return 0;
 }
 EXPORT_SYMBOL(key_unlink);
 


  parent reply	other threads:[~2019-05-22 22:28 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-22 22:28 [PATCH 0/7] keys: Miscellany David Howells
2019-05-22 22:28 ` [PATCH 1/7] keys: sparse: Fix key_fs[ug]id_changed() David Howells
2019-05-24 19:38   ` James Morris
2019-05-22 22:28 ` [PATCH 2/7] keys: sparse: Fix incorrect RCU accesses David Howells
2019-05-25  3:57   ` James Morris
2019-05-22 22:28 ` [PATCH 3/7] keys: sparse: Fix kdoc mismatches David Howells
2019-05-25  3:57   ` James Morris
2019-05-22 22:28 ` David Howells [this message]
2019-05-28 20:41   ` [PATCH 4/7] keys: Break bits out of key_unlink() James Morris
2019-05-22 22:28 ` [PATCH 5/7] keys: Make __key_link_begin() handle lockdep nesting David Howells
2019-05-28 20:42   ` James Morris
2019-05-22 22:28 ` [PATCH 6/7] keys: Add a keyctl to move a key between keyrings David Howells
2019-05-28 20:51   ` James Morris
2019-05-29 21:34   ` David Howells
2019-05-29 23:25   ` Eric Biggers
2019-05-30 13:31   ` David Howells
2019-05-22 22:28 ` [PATCH 7/7] keys: Grant Link permission to possessers of request_key auth keys David Howells
2019-05-28 21:01   ` James Morris

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=155856411142.10428.16280282329908085391.stgit@warthog.procyon.org.uk \
    --to=dhowells@redhat.com \
    --cc=keyrings@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-security-module@vger.kernel.org \
    --subject='Re: [PATCH 4/7] keys: Break bits out of key_unlink()' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).