[PATCH 5.6 036/194] pppoe: only process PADT targeted at local interfaces

Greg Kroah-Hartman
2020-05-18T18:01:24Z

From: Guillaume Nault <gnault@redhat.com>

[ 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 | 3 +++
1 file changed, 3 insertions(+)

--- a/drivers/net/ppp/pppoe.c
+++ b/drivers/net/ppp/pppoe.c
@@ -490,6 +490,9 @@ static int pppoe_disc_rcv(struct sk_buff
if (!skb)
goto out;

+ if (skb->pkt_type != PACKET_HOST)
+ goto abort;
+
if (!pskb_may_pull(skb, sizeof(struct pppoe_hdr)))
goto abort;