Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 8253947e authored by Li Wei's avatar Li Wei Committed by David S. Miller
Browse files

ipv6: fix incorrect route 'expires' value passed to userspace 



When userspace use RTM_GETROUTE to dump route table, with an already
expired route entry, we always got an 'expires' value(2147157)
calculated base on INT_MAX.

The reason of this problem is in the following satement:
	rt->dst.expires - jiffies < INT_MAX
gcc promoted the type of both sides of '<' to unsigned long, thus
a small negative value would be considered greater than INT_MAX.

With the help of Eric Dumazet, do the out of bound checks in
rtnl_put_cacheinfo(), _after_ conversion to clock_t.

Signed-off-by: default avatarLi Wei <lw@cn.fujitsu.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b41a9a66

net/core/rtnetlink.c

+6 −2
Original line number Diff line number Diff line
@@ -625,9 +625,13 @@ int rtnl_put_cacheinfo(struct sk_buff *skb, struct dst_entry *dst, u32 id, 
		.rta_id =  id,

	};



	if (expires)

		ci.rta_expires = jiffies_to_clock_t(expires);

	if (expires) {

		unsigned long clock;



		clock = jiffies_to_clock_t(abs(expires));

		clock = min_t(unsigned long, clock, INT_MAX);

		ci.rta_expires = (expires > 0) ? clock : -clock;

	}

	return nla_put(skb, RTA_CACHEINFO, sizeof(ci), &ci);

}

EXPORT_SYMBOL_GPL(rtnl_put_cacheinfo);

net/ipv6/route.c

+2 −6
Original line number Diff line number Diff line
@@ -2480,12 +2480,8 @@ static int rt6_fill_node(struct net *net, 
		goto nla_put_failure;

	if (nla_put_u32(skb, RTA_PRIORITY, rt->rt6i_metric))

		goto nla_put_failure;

	if (!(rt->rt6i_flags & RTF_EXPIRES))

		expires = 0;

	else if (rt->dst.expires - jiffies < INT_MAX)

		expires = rt->dst.expires - jiffies;

	else

		expires = INT_MAX;



	expires = (rt->rt6i_flags & RTF_EXPIRES) ? rt->dst.expires - jiffies : 0;



	if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, rt->dst.error) < 0)

		goto nla_put_failure;