netdev - [PATCH] netback: don't store invalid vif pointer

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <5486EF48020000780004E1B8@mail.emea.novell.com>
Date:	Tue, 09 Dec 2014 11:47:04 +0000
From:	"Jan Beulich" <JBeulich@...e.com>
To:	"Wei Liu" <wei.liu2@...rix.com>,
	"Ian Campbell" <Ian.Campbell@...citrix.com>
Cc:	"xen-devel" <xen-devel@...ts.xenproject.org>,
	<netdev@...r.kernel.org>
Subject: [PATCH] netback: don't store invalid vif pointer

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 <jbeulich@...e.com>

--- a/drivers/net/xen-netback/xenbus.c
+++ b/drivers/net/xen-netback/xenbus.c
@@ -404,6 +404,7 @@ static int backend_create_xenvif(struct 
 	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 
 		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;



--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html