[PATCH 4.14 06/46] pppoe: only process PADT targeted at local interfaces

Greg Kroah-Hartman
2020-06-09T18:18:46Z

From: Guillaume Nault <gnault@redhat.com>

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>
---
drivers/net/ppp/pppoe.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/net/ppp/pppoe.c b/drivers/net/ppp/pppoe.c
index fa7121dcab67..202a0f415e1e 100644
--- a/drivers/net/ppp/pppoe.c
+++ b/drivers/net/ppp/pppoe.c
@@ -497,6 +497,9 @@ 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;

--
2.25.1