From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20120330194859.751295658@linuxfoundation.org> Date: Fri, 30 Mar 2012 12:51:12 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Ben Greear , Dave Jones , Eric Dumazet , "David S. Miller" Subject: [ 167/175] net: fix a potential rcu_read_lock() imbalance in rt6_fill_node() In-Reply-To: <20120330195801.GA31806@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.3-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit 94f826b8076e2cb92242061e92f21b5baa3eccc2 ] Commit f2c31e32b378 (net: fix NULL dereferences in check_peer_redir() ) added a regression in rt6_fill_node(), leading to rcu_read_lock() imbalance. Thats because NLA_PUT() can make a jump to nla_put_failure label. Fix this by using nla_put() Many thanks to Ben Greear for his help Reported-by: Ben Greear Reported-by: Dave Jones Signed-off-by: Eric Dumazet Tested-by: Ben Greear Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv6/route.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -2461,8 +2461,12 @@ static int rt6_fill_node(struct net *net rcu_read_lock(); n = dst_get_neighbour_noref(&rt->dst); - if (n) - NLA_PUT(skb, RTA_GATEWAY, 16, &n->primary_key); + if (n) { + if (nla_put(skb, RTA_GATEWAY, 16, &n->primary_key) < 0) { + rcu_read_unlock(); + goto nla_put_failure; + } + } rcu_read_unlock(); if (rt->dst.dev)