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>
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 @@
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 @@
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 @@
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;