Re: [PATCH] vhost: fix error handling in vring ioctls

From: Laurent Chavey
Date: Wed Mar 17 2010 - 13:55:27 EST


Acked-by: chavey@xxxxxxxxxx


On Wed, Mar 17, 2010 at 7:42 AM, Michael S. Tsirkin <mst@xxxxxxxxxx> wrote:
> 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@xxxxxxxxx>
> Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
> ---
>  drivers/vhost/vhost.c |   18 ++++++++++++------
>  1 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)
>                if (r < 0)
>                        break;
>                eventfp = f.fd == -1 ? NULL : eventfd_fget(f.fd);
> -               if (IS_ERR(eventfp))
> -                       return PTR_ERR(eventfp);
> +               if (IS_ERR(eventfp)) {
> +                       r = PTR_ERR(eventfp);
> +                       break;
> +               }
>                if (eventfp != vq->kick) {
>                        pollstop = filep = vq->kick;
>                        pollstart = vq->kick = eventfp;
> @@ -489,8 +491,10 @@ static long vhost_set_vring(struct vhost_dev *d, int ioctl, void __user *argp)
>                if (r < 0)
>                        break;
>                eventfp = f.fd == -1 ? NULL : eventfd_fget(f.fd);
> -               if (IS_ERR(eventfp))
> -                       return PTR_ERR(eventfp);
> +               if (IS_ERR(eventfp)) {
> +                       r = PTR_ERR(eventfp);
> +                       break;
> +               }
>                if (eventfp != vq->call) {
>                        filep = vq->call;
>                        ctx = vq->call_ctx;
> @@ -505,8 +509,10 @@ static long vhost_set_vring(struct vhost_dev *d, int ioctl, void __user *argp)
>                if (r < 0)
>                        break;
>                eventfp = f.fd == -1 ? NULL : eventfd_fget(f.fd);
> -               if (IS_ERR(eventfp))
> -                       return PTR_ERR(eventfp);
> +               if (IS_ERR(eventfp)) {
> +                       r = PTR_ERR(eventfp);
> +                       break;
> +               }
>                if (eventfp != vq->error) {
>                        filep = vq->error;
>                        vq->error = eventfp;
> --
> 1.7.0.18.g0d53a5
> --
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