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authorCong Wang <amwang@redhat.com>2013-03-22 19:14:07 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-04-05 10:04:38 -0700
commita83417946df6c57fbb4d4383c992c5ffd59b56c2 (patch)
treeb3f4589670a0d6846f498628eb76f4d881cf44ff /net
parentd1f60c6d91df21978218af4f5442993749ecbf7e (diff)
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8021q: fix a potential use-after-free
[ 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@redhat.com> Cc: Patrick McHardy <kaber@trash.net> Cc: "David S. Miller" <davem@davemloft.net> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
-rw-r--r--net/8021q/vlan.c14
1 files changed, 7 insertions, 7 deletions
diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c
index cf4a49c5623..e22b8ada799 100644
--- a/net/8021q/vlan.c
+++ b/net/8021q/vlan.c
@@ -86,13 +86,6 @@ void unregister_vlan_dev(struct net_device *dev, struct list_head *head)
grp = &vlan_info->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)
- vlan_vid_del(real_dev, vlan_id);
-
grp->nr_vlan_devs--;
if (vlan->flags & VLAN_FLAG_GVRP)
@@ -108,6 +101,13 @@ void unregister_vlan_dev(struct net_device *dev, struct list_head *head)
if (grp->nr_vlan_devs == 0)
vlan_gvrp_uninit_applicant(real_dev);
+ /* 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)
+ vlan_vid_del(real_dev, vlan_id);
+
/* Get rid of the vlan's reference to real_dev */
dev_put(real_dev);
}