Commit 25cc8f07 authored Jun 05, 2015 by Robert Shearman Committed by David S. Miller Jun 07, 2015

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: 03c57747 ("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>

parent e51000db

net/mpls/af_mpls.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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,

net/mpls/internal.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -16,6 +16,7 @@ struct mpls_dev {
		int input_enabled;

		struct ctl_table_header *sysctl;
		struct rcu_head rcu;
		};

		struct sk_buff;