pppoe: only process PADT targeted at local interfaces
authorGuillaume Nault <gnault@redhat.com>
Thu, 14 May 2020 10:15:39 +0000 (12:15 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 20 May 2020 06:20:09 +0000 (08:20 +0200)
[ Upstream commit b8c158395119be62294da73646a3953c29ac974b ]

We don't want to disconnect a session because of a stray PADT arriving
while the interface is in promiscuous mode.
Furthermore, multicast and broadcast packets make no sense here, so
only PACKET_HOST is accepted.

Reported-by: David Balažic <xerces9@gmail.com>
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/net/ppp/pppoe.c

index a44dd3c..087b016 100644 (file)
@@ -492,6 +492,9 @@ static int pppoe_disc_rcv(struct sk_buff *skb, struct net_device *dev,
        if (!skb)
                goto out;
 
+       if (skb->pkt_type != PACKET_HOST)
+               goto abort;
+
        if (!pskb_may_pull(skb, sizeof(struct pppoe_hdr)))
                goto abort;