From: David Howells <dhowells@redhat.com>
To: keyrings@vger.kernel.org, ebiggers@kernel.org
Cc: dhowells@redhat.com, linux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH 05/10] keys: Break bits out of key_unlink() [ver #3]
Date: Wed, 19 Jun 2019 14:19:23 +0100 [thread overview]
Message-ID: <156095036385.9363.921620306060848348.stgit@warthog.procyon.org.uk> (raw)
In-Reply-To: <156095032052.9363.8954337545422131435.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 | 88 ++++++++++++++++++++++++++++++++++++-----------
1 file changed, 67 insertions(+), 21 deletions(-)
diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index ca6694ba1773..6990c7761eaa 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);
+/*
+ * Lock a keyring for unlink.
+ */
+static int __key_unlink_lock(struct key *keyring)
+ __acquires(&keyring->sem)
+{
+ if (keyring->type != &key_type_keyring)
+ return -ENOTDIR;
+
+ down_write(&keyring->sem);
+ return 0;
+}
+
+/*
+ * Begin the process of unlinking a key from a keyring.
+ */
+static int __key_unlink_begin(struct key *keyring, struct key *key,
+ struct assoc_array_edit **_edit)
+{
+ struct assoc_array_edit *edit;
+
+ BUG_ON(*_edit != NULL);
+
+ edit = assoc_array_delete(&keyring->keys, &keyring_assoc_array_ops,
+ &key->index_key);
+ if (IS_ERR(edit))
+ return PTR_ERR(edit);
+
+ if (!edit)
+ return -ENOENT;
+
+ *_edit = edit;
+ return 0;
+}
+
+/*
+ * 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.
@@ -1401,33 +1460,20 @@ EXPORT_SYMBOL(key_link);
*/
int key_unlink(struct key *keyring, struct key *key)
{
- struct assoc_array_edit *edit;
+ struct assoc_array_edit *edit = NULL;
int ret;
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_lock(keyring);
+ if (ret < 0)
+ return ret;
-error:
- up_write(&keyring->sem);
+ ret = __key_unlink_begin(keyring, key, &edit);
+ if (ret == 0)
+ __key_unlink(keyring, key, &edit);
+ __key_unlink_end(keyring, key, edit);
return ret;
}
EXPORT_SYMBOL(key_unlink);
next prev parent reply other threads:[~2019-06-19 13:19 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-19 13:18 [PATCH 00/10] keys: Miscellany [ver #3] David Howells
2019-06-19 13:18 ` [PATCH 01/10] keys: sparse: Fix key_fs[ug]id_changed() " David Howells
2019-06-19 13:19 ` [PATCH 02/10] keys: sparse: Fix incorrect RCU accesses " David Howells
2019-06-19 13:19 ` [PATCH 03/10] keys: sparse: Fix kdoc mismatches " David Howells
2019-06-19 13:19 ` [PATCH 04/10] keys: Change keyring_serialise_link_sem to a mutex " David Howells
2019-06-19 13:19 ` David Howells [this message]
2019-06-19 13:19 ` [PATCH 06/10] keys: Hoist locking out of __key_link_begin() " David Howells
2019-06-19 13:19 ` [PATCH 07/10] keys: Add a keyctl to move a key between keyrings " David Howells
2019-06-19 13:19 ` [PATCH 08/10] keys: Grant Link permission to possessers of request_key auth keys " David Howells
2019-06-19 13:19 ` [PATCH 09/10] keys: Reuse keyring_index_key::desc_len in lookup_user_key() " David Howells
2019-06-19 13:20 ` [PATCH 10/10] keys: Add capability-checking keyctl function " David Howells
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=156095036385.9363.921620306060848348.stgit@warthog.procyon.org.uk \
--to=dhowells@redhat.com \
--cc=ebiggers@kernel.org \
--cc=keyrings@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
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).