linux-kernel - [PATCH net-next 12/13] ipvlan: Ignore PACKET_LOOPBACK in handle_mode

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <20251118100046.2944392-13-skorodumov.dmitry@huawei.com>
Date: Tue, 18 Nov 2025 13:00:44 +0300
From: Dmitry Skorodumov <skorodumov.dmitry@...wei.com>
To: <netdev@...r.kernel.org>, <linux-kernel@...r.kernel.org>
CC: <andrey.bokhanko@...wei.com>, <edumazet@...gle.com>, Dmitry Skorodumov
	<skorodumov.dmitry@...wei.com>, Andrew Lunn <andrew+netdev@...n.ch>, "David
 S. Miller" <davem@...emloft.net>, Jakub Kicinski <kuba@...nel.org>, Paolo
 Abeni <pabeni@...hat.com>
Subject: [PATCH net-next 12/13] ipvlan: Ignore PACKET_LOOPBACK in handle_mode_l2()

Packets with pkt_type == PACKET_LOOPBACK are captured by
handle_frame() function, but they don't have L2 header.
We should not process them in handle_mode_l2().

This doesn't affect old L2 functionality, since handling
was anyway incorrect.

Handle them the same way as in br_handle_frame():
just pass the skb.

To observe invalid behaviour, just start "ping -b" on bcast address
of port-interface.

Signed-off-by: Dmitry Skorodumov <skorodumov.dmitry@...wei.com>
---
 drivers/net/ipvlan/ipvlan_core.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ipvlan/ipvlan_core.c b/drivers/net/ipvlan/ipvlan_core.c
index 425d2a12a4ee..d6975d5e2198 100644
--- a/drivers/net/ipvlan/ipvlan_core.c
+++ b/drivers/net/ipvlan/ipvlan_core.c
@@ -1160,6 +1160,9 @@ static rx_handler_result_t ipvlan_handle_mode_l2(struct sk_buff **pskb,
 	struct sk_buff *skb = *pskb;
 	bool need_eth_fix;
 
+	if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
+		return RX_HANDLER_PASS;
+
 	/* Ignore already seen packets. */
 	if (ipvlan_is_skb_marked(skb, port->dev))
 		return RX_HANDLER_PASS;
-- 
2.25.1