l2tp: hold socket before dropping lock in l2tp_ip{, 6}_recv()

Socket must be held while under the protection of the l2tp lock; there
is no guarantee that sk remains valid after the read_unlock_bh() call.

Same issue for l2tp_ip and l2tp_ip6.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Guillaume Nault 2016-11-29 13:09:45 +01:00 committed by David S. Miller
parent 0382a25af3
commit a3c18422a4
2 changed files with 12 additions and 10 deletions

View File

@ -183,14 +183,15 @@ pass_up:
read_lock_bh(&l2tp_ip_lock);
sk = __l2tp_ip_bind_lookup(net, iph->daddr, 0, tunnel_id);
if (!sk) {
read_unlock_bh(&l2tp_ip_lock);
goto discard;
}
sock_hold(sk);
read_unlock_bh(&l2tp_ip_lock);
}
if (sk == NULL)
goto discard;
sock_hold(sk);
if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
goto discard_put;

View File

@ -198,14 +198,15 @@ pass_up:
read_lock_bh(&l2tp_ip6_lock);
sk = __l2tp_ip6_bind_lookup(net, &iph->daddr,
0, tunnel_id);
if (!sk) {
read_unlock_bh(&l2tp_ip6_lock);
goto discard;
}
sock_hold(sk);
read_unlock_bh(&l2tp_ip6_lock);
}
if (sk == NULL)
goto discard;
sock_hold(sk);
if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
goto discard_put;