linux/net/l2tp
David Bauer d70b592551 l2tp: reset skb control buffer on xmit
The L2TP stack did not reset the skb control buffer before sending the
encapsulated package.

In a setup with an ath10k radio and batman-adv over an L2TP tunnel
massive fragmentations happen sporadically if the L2TP tunnel is
established over IPv4.

L2TP might reset some of the fields in the IP control buffer, but L2TP
assumes the type of the control buffer to be of an IPv4 packet.

In case the L2TP interface is used as a batadv hardif or the packet is
an IPv6 packet, this assumption breaks.

Clear the entire control buffer to avoid such mishaps altogether.

Fixes: f77ae93904 ("[PPPOL2TP]: Reset meta-data in xmit function")
Signed-off-by: David Bauer <mail@david-bauer.net>
Link: https://patch.msgid.link/20251118001619.242107-1-mail@david-bauer.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-11-20 11:52:24 +01:00
..
Kconfig
Makefile l2tp: add tracepoint infrastructure to core 2020-08-22 12:44:37 -07:00
l2tp_core.c l2tp: reset skb control buffer on xmit 2025-11-20 11:52:24 +01:00
l2tp_core.h l2tp: improve tunnel/session refcount helpers 2024-08-11 04:38:50 +01:00
l2tp_debugfs.c l2tp: improve tunnel/session refcount helpers 2024-08-11 04:38:50 +01:00
l2tp_eth.c net: move misc netdev_lock flavors to a separate header 2025-03-08 09:06:50 -08:00
l2tp_ip.c l2tp: Use inet_sk_init_flowi4() in l2tp_ip_sendmsg(). 2024-12-20 13:50:09 -08:00
l2tp_ip6.c net: annotate races around sk->sk_uid 2025-06-23 17:04:03 -07:00
l2tp_netlink.c genetlink: hold RCU in genlmsg_mcast() 2024-10-15 17:52:58 -07:00
l2tp_ppp.c l2tp: do not use sock_hold() in pppol2tp_session_get_sock() 2025-08-27 17:16:13 -07:00
trace.h l2tp: add tracepoint definitions in trace.h 2020-08-22 12:44:37 -07:00