vhost: fix error handling in RESET_OWNER ioctl
RESET_OWNER ioctl would leave the fd in a bad state if
memory allocation failed: device is stopped
but owner is not reset. Make state changes
after allocating memory, such that a failed
ioctl has no effect.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 6dcd81c..749b5ab 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -386,21 +386,19 @@
return err;
}
-/* Caller should have device mutex */
-long vhost_dev_reset_owner(struct vhost_dev *dev)
+struct vhost_memory *vhost_dev_reset_owner_prepare(void)
{
- struct vhost_memory *memory;
+ return kmalloc(offsetof(struct vhost_memory, regions), GFP_KERNEL);
+}
- /* Restore memory to default empty mapping. */
- memory = kmalloc(offsetof(struct vhost_memory, regions), GFP_KERNEL);
- if (!memory)
- return -ENOMEM;
-
+/* Caller should have device mutex */
+void vhost_dev_reset_owner(struct vhost_dev *dev, struct vhost_memory *memory)
+{
vhost_dev_cleanup(dev, true);
+ /* Restore memory to default empty mapping. */
memory->nregions = 0;
RCU_INIT_POINTER(dev->memory, memory);
- return 0;
}
void vhost_dev_stop(struct vhost_dev *dev)