From: David Miller <davem@davemloft.net>
To: mst@redhat.com
Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
virtio-dev@lists.oasis-open.org,
virtualization@lists.linux-foundation.org,
netdev@vger.kernel.org, jasowang@redhat.com
Subject: Re: [PATCH net v2] vhost: fix a theoretical race in device cleanup
Date: Thu, 13 Feb 2014 18:48:25 -0500 (EST) [thread overview]
Message-ID: <20140213.184825.32399543190618715.davem@davemloft.net> (raw)
In-Reply-To: <1392284540-2031-1-git-send-email-mst@redhat.com>
From: "Michael S. Tsirkin" <mst@redhat.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@redhat.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.
prev parent reply other threads:[~2014-02-13 23:48 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-13 9:45 Michael S. Tsirkin
2014-02-13 10:01 ` [virtio-dev] " Jason Wang
2014-02-13 23:48 ` David Miller [this message]
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