mpls: fix possible use after free of device

The mpls device is used in an RCU read context without a lock being
held. As the memory is freed without waiting for the RCU grace period
to elapse, the freed memory could still be in use.

Address this by using kfree_rcu to free the memory for the mpls device
after the RCU grace period has elapsed.

Fixes: 03c57747a7 ("mpls: Per-device MPLS state")
Signed-off-by: Robert Shearman <rshearma@brocade.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Robert Shearman 2015-06-05 18:54:45 +01:00 committed by David S. Miller
parent e51000db4c
commit 25cc8f0763
2 changed files with 2 additions and 1 deletions

View file

@ -541,7 +541,7 @@ static void mpls_ifdown(struct net_device *dev)
RCU_INIT_POINTER(dev->mpls_ptr, NULL);
kfree(mdev);
kfree_rcu(mdev, rcu);
}
static int mpls_dev_notify(struct notifier_block *this, unsigned long event,

View file

@ -16,6 +16,7 @@ struct mpls_dev {
int input_enabled;
struct ctl_table_header *sysctl;
struct rcu_head rcu;
};
struct sk_buff;