ipv6: route: enforce RCU protection in rt6_update_exception_stamp_rt() (193f3685) · Commits · 戴 / test

We must access rt6_info->from under RCU read lock: move the dereference under such lock, with proper annotation. v1 -> v2: - avoid using multiple, racy, fetch operations for rt->from Fixes: ("net/ipv6: Make from in rt6_info rcu protected") Signed-off-by:

Paolo Abeni <pabeni@redhat.com> Reviewed-by:

David Ahern <dsahern@gmail.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/ipv6/route.c

+6 −5

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();
		}

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