xen/pvcalls: Fix a check in pvcalls_front_remove()

bedata->ref can't be less than zero because it's unsigned. This affects certain error paths in probe. We first set ->ref = -1 and then we set it to a valid value later. Fixes: 2196819 ("xen/pvcalls: connect to the backend") Signed-off-by: Dan Carpenter <[email protected]> Reviewed-by: Juergen Gross <[email protected]> Reviewed-by: Stefano Stabellini <[email protected]> Signed-off-by: Boris Ostrovsky <[email protected]>
ambv · Dec 6, 2017 · 1ab134c · 1ab134c
1 parent 8c71fa8
commit 1ab134c
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c
@@ -1103,7 +1103,7 @@ static int pvcalls_front_remove(struct xenbus_device *dev)
 			kfree(map);
 		}
 	}
-	if (bedata->ref >= 0)
+	if (bedata->ref != -1)
 		gnttab_end_foreign_access(bedata->ref, 0, 0);
 	kfree(bedata->ring.sring);
 	kfree(bedata);