diff options
| author | Cong Wang <amwang@redhat.com> | 2013-03-22 19:14:07 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-03-24 17:27:28 -0400 |
| commit | 4a7df340ed1bac190c124c1601bfc10cde9fb4fb (patch) | |
| tree | 40d9d03a585e344d405d25648a5336d9b92721dc | |
| parent | 9979a55a833883242e3a29f3596676edd7199c46 (diff) | |
| download | lwn-4a7df340ed1bac190c124c1601bfc10cde9fb4fb.tar.gz lwn-4a7df340ed1bac190c124c1601bfc10cde9fb4fb.zip | |
8021q: fix a potential use-after-free
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.
Cc: Patrick McHardy <kaber@trash.net>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/8021q/vlan.c | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c index a18714469bf7..85addcd9372b 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_MVRP) @@ -114,6 +107,13 @@ void unregister_vlan_dev(struct net_device *dev, struct list_head *head) 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); } |