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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