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Commit b78f2b77 authored by Eric Dumazet's avatar Eric Dumazet Committed by Greg Kroah-Hartman
Browse files

tcp_metrics: add missing barriers on delete 



[ Upstream commit cbc3a153222805d65f821e10f4f78b6afce06f86 ]

When removing an item from RCU protected list, we must prevent
store-tearing, using rcu_assign_pointer() or WRITE_ONCE().

Fixes: 04f721c6 ("tcp_metrics: Rewrite tcp_metrics_flush_all")
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Reviewed-by: default avatarDavid Ahern <dsahern@kernel.org>
Acked-by: default avatarNeal Cardwell <ncardwell@google.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent af0fe2c2

net/ipv4/tcp_metrics.c

+2 −2
Original line number Diff line number Diff line
@@ -903,7 +903,7 @@ static void tcp_metrics_flush_all(struct net *net) 
			match = net ? net_eq(tm_net(tm), net) :

				!refcount_read(&tm_net(tm)->count);

			if (match) {

				*pp = tm->tcpm_next;

				rcu_assign_pointer(*pp, tm->tcpm_next);

				kfree_rcu(tm, rcu_head);

			} else {

				pp = &tm->tcpm_next;
@@ -944,7 +944,7 @@ static int tcp_metrics_nl_cmd_del(struct sk_buff *skb, struct genl_info *info) 
		if (addr_same(&tm->tcpm_daddr, &daddr) &&

		    (!src || addr_same(&tm->tcpm_saddr, &saddr)) &&

		    net_eq(tm_net(tm), net)) {

			*pp = tm->tcpm_next;

			rcu_assign_pointer(*pp, tm->tcpm_next);

			kfree_rcu(tm, rcu_head);

			found = true;

		} else {