From mboxrd@z Thu Jan  1 00:00:00 1970
From: Laurent Chavey <chavey@google.com>
Subject: Re: [PATCH] vhost: fix error handling in vring ioctls
Date: Wed, 17 Mar 2010 10:54:57 -0700
Message-ID: <97949e3e1003171054q3bee27d5yce0d92ae33e5b5ca@mail.gmail.com>
References: <20100317144249.GA3984@redhat.com>
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Cc: Jiri Slaby <jirislaby@gmail.com>, kvm@vger.kernel.org,
	virtualization@lists.osdl.org, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org
To: "Michael S. Tsirkin" <mst@redhat.com>
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Acked-by: chavey@google.com


On Wed, Mar 17, 2010 at 7:42 AM, Michael S. Tsirkin <mst@redhat.com> wr=
ote:
> Stanse found a locking problem in vhost_set_vring:
> several returns from VHOST_SET_VRING_KICK, VHOST_SET_VRING_CALL,
> VHOST_SET_VRING_ERR with the vq->mutex held.
> Fix these up.
>
> Reported-by: Jiri Slaby <jirislaby@gmail.com>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
> =A0drivers/vhost/vhost.c | =A0 18 ++++++++++++------
> =A01 files changed, 12 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> index 7cd55e0..7bd7a1e 100644
> --- a/drivers/vhost/vhost.c
> +++ b/drivers/vhost/vhost.c
> @@ -476,8 +476,10 @@ static long vhost_set_vring(struct vhost_dev *d,=
 int ioctl, void __user *argp)
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0if (r < 0)
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0break;
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0eventfp =3D f.fd =3D=3D -1 ? NULL : ev=
entfd_fget(f.fd);
> - =A0 =A0 =A0 =A0 =A0 =A0 =A0 if (IS_ERR(eventfp))
> - =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 return PTR_ERR(eventfp)=
;
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 if (IS_ERR(eventfp)) {
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 r =3D PTR_ERR(eventfp);
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 break;
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 }
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0if (eventfp !=3D vq->kick) {
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0pollstop =3D filep =3D=
 vq->kick;
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0pollstart =3D vq->kick=
 =3D eventfp;
> @@ -489,8 +491,10 @@ static long vhost_set_vring(struct vhost_dev *d,=
 int ioctl, void __user *argp)
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0if (r < 0)
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0break;
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0eventfp =3D f.fd =3D=3D -1 ? NULL : ev=
entfd_fget(f.fd);
> - =A0 =A0 =A0 =A0 =A0 =A0 =A0 if (IS_ERR(eventfp))
> - =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 return PTR_ERR(eventfp)=
;
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 if (IS_ERR(eventfp)) {
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 r =3D PTR_ERR(eventfp);
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 break;
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 }
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0if (eventfp !=3D vq->call) {
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0filep =3D vq->call;
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ctx =3D vq->call_ctx;
> @@ -505,8 +509,10 @@ static long vhost_set_vring(struct vhost_dev *d,=
 int ioctl, void __user *argp)
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0if (r < 0)
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0break;
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0eventfp =3D f.fd =3D=3D -1 ? NULL : ev=
entfd_fget(f.fd);
> - =A0 =A0 =A0 =A0 =A0 =A0 =A0 if (IS_ERR(eventfp))
> - =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 return PTR_ERR(eventfp)=
;
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 if (IS_ERR(eventfp)) {
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 r =3D PTR_ERR(eventfp);
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 break;
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 }
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0if (eventfp !=3D vq->error) {
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0filep =3D vq->error;
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0vq->error =3D eventfp;
> --
> 1.7.0.18.g0d53a5
> --
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