[PATCH V3 02/10] vhost: don't set uaddr for invalid address

We should not setup uaddr for the invalid address, otherwise we may
try to pin or prefetch mapping of wrong pages.

Fixes: 7f466032dc9e ("vhost: access vq metadata through kernel virtual address")
Signed-off-by: Jason Wang <redacted>
---
 drivers/vhost/vhost.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 0536f8526359..488380a581dc 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c

@@ -2082,7 +2082,8 @@ static long vhost_vring_set_num_addr(struct vhost_dev *d,
 	}
 
 #if VHOST_ARCH_CAN_ACCEL_UACCESS
-	vhost_setup_vq_uaddr(vq);
+	if (r == 0)
+		vhost_setup_vq_uaddr(vq);
 
 	if (d->mm)
 		mmu_notifier_register(&d->mmu_notifier, d->mm);

-- 
2.18.1