From e67d8dd0e2c1b8b4573a6a3f05f609be230dfaff Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Tue, 9 Dec 2014 11:47:04 +0000 Subject: [PATCH 3/4] netback: don't store invalid vif pointer Origin: https://git.kernel.org/linus/f15650b7f94879667f253bc32de7431c1baf2d6e When xenvif_alloc() fails, it returns a non-NULL error indicator. To avoid eventual races, we shouldn't store that into struct backend_info as readers of it only check for NULL. Signed-off-by: Jan Beulich Acked-by: Ian Campbell Signed-off-by: David S. Miller --- drivers/net/xen-netback/xenbus.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c index 0b4f1c7..cc8f8ba 100644 --- a/drivers/net/xen-netback/xenbus.c +++ b/drivers/net/xen-netback/xenbus.c @@ -404,6 +404,7 @@ static int backend_create_xenvif(struct backend_info *be) int err; long handle; struct xenbus_device *dev = be->dev; + struct xenvif *vif; if (be->vif != NULL) return 0; @@ -414,13 +415,13 @@ static int backend_create_xenvif(struct backend_info *be) return (err < 0) ? err : -EINVAL; } - be->vif = xenvif_alloc(&dev->dev, dev->otherend_id, handle); - if (IS_ERR(be->vif)) { - err = PTR_ERR(be->vif); - be->vif = NULL; + vif = xenvif_alloc(&dev->dev, dev->otherend_id, handle); + if (IS_ERR(vif)) { + err = PTR_ERR(vif); xenbus_dev_fatal(dev, err, "creating interface"); return err; } + be->vif = vif; kobject_uevent(&dev->dev.kobj, KOBJ_ONLINE); return 0; -- 1.7.10.4