linux-kernel - [ 45/56] 8021q: fix a potential use-after-free

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

Message-Id: <20130402224717.071394205@linuxfoundation.org>
Date:	Tue,  2 Apr 2013 15:50:12 -0700
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	linux-kernel@...r.kernel.org
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	stable@...r.kernel.org, Cong Wang <amwang@...hat.com>,
	Patrick McHardy <kaber@...sh.net>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>
Subject: [ 45/56] 8021q: fix a potential use-after-free

3.0-stable review patch.  If anyone has any objections, please let me know.

------------------


From: Cong Wang <amwang@...hat.com>

[ Upstream commit 4a7df340ed1bac190c124c1601bfc10cde9fb4fb ]

vlan_vid_del() could possibly free ->vlan_info after a RCU grace
period, however, we may still refer to the freed memory area
by 'grp' pointer. Found by code inspection.

This patch moves vlan_vid_del() as behind as possible.

Signed-off-by: Cong Wang <amwang@...hat.com>
Cc: Patrick McHardy <kaber@...sh.net>
Cc: "David S. Miller" <davem@...emloft.net>
Acked-by: Eric Dumazet <edumazet@...gle.com>
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 net/8021q/vlan.c |   14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

--- a/net/8021q/vlan.c
+++ b/net/8021q/vlan.c
@@ -108,13 +108,6 @@ void unregister_vlan_dev(struct net_devi
 	grp = rtnl_dereference(real_dev->vlgrp);
 	BUG_ON(!grp);
 
-	/* Take it out of our own structures, but be sure to interlock with
-	 * HW accelerating devices or SW vlan input packet processing if
-	 * VLAN is not 0 (leave it there for 802.1p).
-	 */
-	if (vlan_id && (real_dev->features & NETIF_F_HW_VLAN_FILTER))
-		ops->ndo_vlan_rx_kill_vid(real_dev, vlan_id);
-
 	grp->nr_vlans--;
 
 	if (vlan->flags & VLAN_FLAG_GVRP)
@@ -139,6 +132,13 @@ void unregister_vlan_dev(struct net_devi
 		call_rcu(&grp->rcu, vlan_rcu_free);
 	}
 
+	/* Take it out of our own structures, but be sure to interlock with
+	 * HW accelerating devices or SW vlan input packet processing if
+	 * VLAN is not 0 (leave it there for 802.1p).
+	 */
+	if (vlan_id && (real_dev->features & NETIF_F_HW_VLAN_FILTER))
+		ops->ndo_vlan_rx_kill_vid(real_dev, vlan_id);
+
 	/* Get rid of the vlan's reference to real_dev */
 	dev_put(real_dev);
 }


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/