linux-kernel - Re: [PATCH] vfs: Fix possible NULL pointer dereference in inode

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 10 Jan 2014 08:18:18 +0800
From:	Linus Torvalds <torvalds@...ux-foundation.org>
To:	Al Viro <viro@...iv.linux.org.uk>
Cc:	Eric Paris <eparis@...hat.com>,
	Steven Rostedt <rostedt@...dmis.org>,
	Paul McKenney <paulmck@...ux.vnet.ibm.com>,
	Dave Chinner <david@...morbit.com>,
	linux-fsdevel <linux-fsdevel@...r.kernel.org>,
	James Morris <james.l.morris@...cle.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Stephen Smalley <sds@...ho.nsa.gov>,
	"Theodore Ts'o" <tytso@....edu>, stable <stable@...r.kernel.org>,
	Paul Moore <paul@...l-moore.com>,
	LKML <linux-kernel@...r.kernel.org>,
	Matthew Wilcox <matthew@....cx>,
	Christoph Hellwig <hch@...radead.org>
Subject: Re: [PATCH] vfs: Fix possible NULL pointer dereference in inode_permission()

On Fri, Jan 10, 2014 at 8:06 AM, Al Viro <viro@...iv.linux.org.uk> wrote:
>
> Sure, we can separate the simple "just do call_rcu(...->free_inode)" case
> and hit it whenever full ->free_inode is there and ->destroy_inode isn't.
> Not too pretty, but removal of tons of boilerplate might be worth doing
> that anyway.

Yeah.

> But ->destroy_inode() is still needed for cases where fs
> has its own idea of inode lifetime rules.  Again, check what XFS is doing
> in that area...

Ok, so we can't change destroy_inode, and we'd need to add a new op
for just freeing it.

Painful mainly because there are so many filesystems, but it shouldn't
be *complicated*.

> There's an extra source of headache, BTW - what about the "LSM stacking"
> crowd and their plans?

LSM stacking is a pipedream right  now anyway, isn't it? It's been
talked about for years and years, I've never seen a patch-set that is
even remotely something we'd seriously consider.

            Linus
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/