xen/pvcalls-back: test for errors when calling backend_connect()

commit c8d70a29d6bbc956013f3401f92a4431a9385a3c upstream.

backend_connect() can fail, so switch the device to connected only if
no error occurred.

Fixes: 0a9c75c2c7258f2 ("xen/pvcalls: xenbus state handling")
Cc: stable@vger.kernel.org
Signed-off-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20200511074231.19794-1-jgross@suse.com
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/xen/pvcalls-back.c b/drivers/xen/pvcalls-back.c
index c57c71b7d53dbab128c27bfdaadc4ac218469eb2..ffe9bd843922b2d93b06de451785cf55e5168c58 100644 (file)
--- a/drivers/xen/pvcalls-back.c
+++ b/drivers/xen/pvcalls-back.c
@@ -1087,7 +1087,8 @@ static void set_backend_state(struct xenbus_device *dev,
                case XenbusStateInitialised:
                        switch (state) {
                        case XenbusStateConnected:
-                               backend_connect(dev);
+                               if (backend_connect(dev))
+                                       return;
                                xenbus_switch_state(dev, XenbusStateConnected);
                                break;
                        case XenbusStateClosing: