From: Jeff Layton <jlayton@redhat.com>
To: David Howells <dhowells@redhat.com>
Cc: steved@redhat.com, jmorris@namei.org,
linux-security-module@vger.kernel.org, keyrings@linux-nfs.org,
linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [Keyrings] [PATCH 7/9] KEYS: Permit in-place link replacement in keyring list
Date: Mon, 19 Mar 2012 10:44:32 -0400 [thread overview]
Message-ID: <20120319104432.56fe1e66@redhat.com> (raw)
In-Reply-To: <20120208110400.4050.11565.stgit@warthog.procyon.org.uk>
On Wed, 08 Feb 2012 11:04:00 +0000
David Howells <dhowells@redhat.com> wrote:
> @@ -154,11 +164,10 @@ static void keyring_destroy(struct key *keyring)
> write_unlock(&keyring_name_lock);
> }
>
> - klist = rcu_dereference_check(keyring->payload.subscriptions,
> - atomic_read(&keyring->usage) == 0);
> + klist = rcu_access_pointer(keyring->payload.subscriptions);
> if (klist) {
> for (loop = klist->nkeys - 1; loop >= 0; loop--)
> - key_put(klist->keys[loop]);
> + key_put(rcu_access_pointer(klist->keys[loop]));
> kfree(klist);
> }
> }
Why is it safe to use key_put(rcu_access_pointer(...)) ? Clearly that
pointer will end up being dereferenced, right?
--
Jeff Layton <jlayton@redhat.com>
next prev parent reply other threads:[~2012-03-19 14:44 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-08 11:02 [PATCH 1/9] KEYS: Allow special keyrings to be cleared David Howells
2012-02-08 11:03 ` [PATCH 2/9] keys: update the description with info about "logon" keys David Howells
2012-02-08 11:03 ` [PATCH 3/9] KEYS: Move the key config into security/keys/Kconfig David Howells
2012-02-08 11:03 ` [PATCH 4/9] KEYS: Reorganise keys Makefile David Howells
2012-02-08 11:03 ` [PATCH 5/9] KEYS: Announce key type (un)registration David Howells
2012-02-08 11:03 ` [PATCH 6/9] KEYS: Perform RCU synchronisation on keys prior to key destruction David Howells
2012-03-19 14:31 ` [Keyrings] " Jeff Layton
2012-02-08 11:04 ` [PATCH 7/9] KEYS: Permit in-place link replacement in keyring list David Howells
2012-03-19 14:44 ` Jeff Layton [this message]
2012-03-19 15:39 ` [Keyrings] " David Howells
2012-02-08 11:04 ` [PATCH 8/9] KEYS: Do LRU discard in full keyrings David Howells
2012-02-08 11:04 ` [PATCH 9/9] KEYS: Add invalidation support David Howells
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