From: Al Viro <viro@ZenIV.linux.org.uk>
To: Eric Paris <eparis@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>,
LKML <linux-kernel@vger.kernel.org>,
Stephen Smalley <sds@tycho.nsa.gov>,
James Morris <james.l.morris@oracle.com>,
Paul Moore <paul@paul-moore.com>,
Andrew Morton <akpm@linux-foundation.org>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
stable <stable@vger.kernel.org>
Subject: Re: [PATCH] SELinux: Fix possible NULL pointer dereference in selinux_inode_permission()
Date: Thu, 9 Jan 2014 22:25:55 +0000 [thread overview]
Message-ID: <20140109222555.GK10323@ZenIV.linux.org.uk> (raw)
In-Reply-To: <1389305889.15209.75.camel@localhost>
On Thu, Jan 09, 2014 at 05:18:09PM -0500, Eric Paris wrote:
> > Just RCU-delay freeing the damn thing and treat NULL ->i_security in
> > ->permission() (which can happen only with MAY_NOT_BLOCK in mask) as
> > "return -ECHILD and let the caller deal with that".
> >
> > Modifying every ->destroy_inode() is obviously wrong - there's a lot more
> > filesystems than LSM buggers in the tree.
>
> We just want the same lifetime as the inode. Allocate the security blob
> when the inode is allocated and free the security blob when the inode is
> freed.
Ultimate freeing of struct inode can easily happen outside of VFS - that's
what ->destroy_inode() is for. Moreover, filesystem might decide to do
very odd things to it, as long as it doesn't do so without RCU delay.
So no, there's no single place to do that.
next prev parent reply other threads:[~2014-01-09 22:26 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-09 15:19 [PATCH] SELinux: Fix possible NULL pointer dereference in selinux_inode_permission() Steven Rostedt
2014-01-09 15:31 ` Eric Paris
2014-01-09 15:51 ` Steven Rostedt
2014-01-09 15:57 ` Eric Paris
2014-01-09 16:05 ` Eric Paris
2014-01-09 16:10 ` Stephen Smalley
2014-01-09 16:22 ` Steven Rostedt
2014-01-09 16:25 ` Eric Paris
2014-01-09 20:20 ` Mimi Zohar
2014-01-09 20:24 ` Eric Paris
2014-01-09 22:28 ` Al Viro
2014-01-09 22:17 ` Al Viro
2014-01-09 22:13 ` Al Viro
2014-01-09 22:18 ` Eric Paris
2014-01-09 22:25 ` Al Viro [this message]
2014-01-09 22:45 ` Eric Paris
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