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Commit 7eadfacd authored by Eric Dumazet's avatar Eric Dumazet Committed by Greg Kroah-Hartman
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ipv6: flowlabel: fl6_sock_lookup() must use atomic_inc_not_zero 



[ Upstream commit 65a3c497c0e965a552008db8bc2653f62bc925a1 ]

Before taking a refcount, make sure the object is not already
scheduled for deletion.

Same fix is needed in ipv6_flowlabel_opt()

Fixes: 18367681 ("ipv6 flowlabel: Convert np->ipv6_fl_list to RCU.")
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a5ae5920

net/ipv6/ip6_flowlabel.c

+4 −3
Original line number Diff line number Diff line
@@ -254,9 +254,9 @@ struct ip6_flowlabel *fl6_sock_lookup(struct sock *sk, __be32 label) 
	rcu_read_lock_bh();

	for_each_sk_fl_rcu(np, sfl) {

		struct ip6_flowlabel *fl = sfl->fl;

		if (fl->label == label) {



		if (fl->label == label && atomic_inc_not_zero(&fl->users)) {

			fl->lastuse = jiffies;

			atomic_inc(&fl->users);

			rcu_read_unlock_bh();

			return fl;

		}
@@ -622,7 +622,8 @@ int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen) 
						goto done;

					}

					fl1 = sfl->fl;

					atomic_inc(&fl1->users);

					if (!atomic_inc_not_zero(&fl1->users))

						fl1 = NULL;

					break;

				}

			}