vhost: fix error handling in vring ioctls

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>
Acked-by: Laurent Chavey <chavey@google.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Michael S. Tsirkin 2010-03-17 16:06:11 +02:00
parent 0e25557212
commit 535297a6ae

View file

@ -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;