| From | Luis Henriques <> | Subject | [PATCH 062/102] 8021q: fix a potential use-after-free | Date | Mon, 8 Apr 2013 10:50:17 +0100 |
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3.5.7.10 -stable review patch. If anyone has any objections, please let me know.
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From: Cong Wang <amwang@redhat.com>
commit 4a7df340ed1bac190c124c1601bfc10cde9fb4fb upstream.
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> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- net/8021q/vlan.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c index 9096bcb..8bdc56d 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); } -- 1.8.1.2
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