From 25cc8f0763c972911b1a65099cd10d9f8a45a7b0 Mon Sep 17 00:00:00 2001 From: Robert Shearman Date: Fri, 5 Jun 2015 18:54:45 +0100 Subject: 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: 03c57747a702 ("mpls: Per-device MPLS state") Signed-off-by: Robert Shearman Acked-by: "Eric W. Biederman" Signed-off-by: David S. Miller --- net/mpls/af_mpls.c | 2 +- net/mpls/internal.h | 1 + 2 files changed, 2 insertions(+), 1 deletion(-) (limited to 'net') diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c index 7b3f732269e4..bff427f31924 100644 --- a/net/mpls/af_mpls.c +++ b/net/mpls/af_mpls.c @@ -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, diff --git a/net/mpls/internal.h b/net/mpls/internal.h index b064c345042c..8cabeb5a1cb9 100644 --- a/net/mpls/internal.h +++ b/net/mpls/internal.h @@ -16,6 +16,7 @@ struct mpls_dev { int input_enabled; struct ctl_table_header *sysctl; + struct rcu_head rcu; }; struct sk_buff; -- cgit v1.2.3