Commit 64cc41e6 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'ipv6-route-rcu' 



Paolo Abeni says:

====================
ipv6: route: enforce RCU protection for fib6_info->from

This series addresses a couple of RCU left-over dating back to rt6_info->from
conversion to RCU

v1 -> v2:
 - fix a possible race in patch 1
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents ae3b5641 bf1dc8ba

net/ipv6/route.c

+11 −6
Original line number Diff line number Diff line
@@ -1599,15 +1599,15 @@ static int rt6_remove_exception_rt(struct rt6_info *rt) 
static void rt6_update_exception_stamp_rt(struct rt6_info *rt)

{

	struct rt6_exception_bucket *bucket;

	struct fib6_info *from = rt->from;

	struct in6_addr *src_key = NULL;

	struct rt6_exception *rt6_ex;



	if (!from ||

	    !(rt->rt6i_flags & RTF_CACHE))

		return;

	struct fib6_info *from;



	rcu_read_lock();

	from = rcu_dereference(rt->from);

	if (!from || !(rt->rt6i_flags & RTF_CACHE))

		goto unlock;



	bucket = rcu_dereference(from->rt6i_exception_bucket);



#ifdef CONFIG_IPV6_SUBTREES
@@ -1626,6 +1626,7 @@ static void rt6_update_exception_stamp_rt(struct rt6_info *rt) 
	if (rt6_ex)

		rt6_ex->stamp = jiffies;



unlock:

	rcu_read_unlock();

}
@@ -2742,20 +2743,24 @@ static int ip6_route_check_nh_onlink(struct net *net, 
	u32 tbid = l3mdev_fib_table(dev) ? : RT_TABLE_MAIN;

	const struct in6_addr *gw_addr = &cfg->fc_gateway;

	u32 flags = RTF_LOCAL | RTF_ANYCAST | RTF_REJECT;

	struct fib6_info *from;

	struct rt6_info *grt;

	int err;



	err = 0;

	grt = ip6_nh_lookup_table(net, cfg, gw_addr, tbid, 0);

	if (grt) {

		rcu_read_lock();

		from = rcu_dereference(grt->from);

		if (!grt->dst.error &&

		    /* ignore match if it is the default route */

		    grt->from && !ipv6_addr_any(&grt->from->fib6_dst.addr) &&

		    from && !ipv6_addr_any(&from->fib6_dst.addr) &&

		    (grt->rt6i_flags & flags || dev != grt->dst.dev)) {

			NL_SET_ERR_MSG(extack,

				       "Nexthop has invalid gateway or device mismatch");

			err = -EINVAL;

		}

		rcu_read_unlock();



		ip6_rt_put(grt);

	}

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