linux-kernel - Re: [PATCH net v2] vhost: fix a theoretical race in device cleanup

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] [day] [month] [year] [list]

Message-Id: <20140213.184825.32399543190618715.davem@davemloft.net>
Date:	Thu, 13 Feb 2014 18:48:25 -0500 (EST)
From:	David Miller <davem@...emloft.net>
To:	mst@...hat.com
Cc:	linux-kernel@...r.kernel.org, kvm@...r.kernel.org,
	virtio-dev@...ts.oasis-open.org,
	virtualization@...ts.linux-foundation.org, netdev@...r.kernel.org,
	jasowang@...hat.com
Subject: Re: [PATCH net v2] vhost: fix a theoretical race in device cleanup

From: "Michael S. Tsirkin" <mst@...hat.com>
Date: Thu, 13 Feb 2014 11:45:11 +0200

> vhost_zerocopy_callback accesses VQ right after it drops a ubuf
> reference.  In theory, this could race with device removal which waits
> on the ubuf kref, and crash on use after free.
> 
> Do all accesses within rcu read side critical section, and synchronize
> on release.
> 
> Since callbacks are always invoked from bh, synchronize_rcu_bh seems
> enough and will help release complete a bit faster.
> 
> Signed-off-by: Michael S. Tsirkin <mst@...hat.com>
> ---
> 
> This is was previously posted as part of patch
> series, but it's an independent fix really.
> Theoretical race so not needed for stable I think.

Ok, no -stable, applied.
--
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/