From: Guillaume Nault <gnault@redhat.com>
Date: Thu, 14 May 2020 12:15:39 +0200
Subject: pppoe: only process PADT targeted at local interfaces
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Git-commit: b8c158395119be62294da73646a3953c29ac974b
Patch-mainline: 5.7-rc6
References: networking-stable-20_05_16

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: Jiri Slaby <jslaby@suse.cz>
---
 drivers/net/ppp/pppoe.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/net/ppp/pppoe.c
+++ b/drivers/net/ppp/pppoe.c
@@ -497,6 +497,9 @@ 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;