kernel/linux.git/drivers/net/ovpn/main.c, branch linux-7.0.y

ovpn: fix race between deleting interface and adding new peer

2026-06-01T15:54:43+00:00

[ Upstream commit 982422b11e6f95f766a8cd2c2b1cbdb77e234a61 ] While deleting an existing ovpn interface, there is a very narrow window where adding a new peer via netlink may cause the netdevice to hang and prevent its unregistration. It may happen during ovpn_dellink(), when all existing peers are freed and the device is queued for deregistration, but a CMD_PEER_NEW message comes in adding a new peer that takes again a reference to the netdev. At this point there is no way to release the device because we are under the assumption that all peers were already released. Fix the race condition by releasing all peers in ndo_uninit(), when the netdevice has already been removed from the netdev list. Also ovpn_peer_add() has now an extra check that forces the function to bail out if the device reg_state is not REGISTERED. This way any incoming CMD_PEER_NEW racing with the interface deletion routine will simply stop before adding the peer. Note that the above check happens while holding the netdev_lock to prevent racing netdev state changes. ovpn_dellink() is now empty and can be removed. Reported-by: Hyunwoo Kim Closes: https://lore.kernel.org/netdev/aaVgJ16edTfQkYbx@v4bel/ Suggested-by: Sabrina Dubroca Fixes: 80747caef33d ("ovpn: introduce the ovpn_peer object") Reviewed-by: Sabrina Dubroca Signed-off-by: Antonio Quartulli Signed-off-by: Sasha Levin

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

ovpn: don't drop skb's dst when xmitting packet

2025-05-15T11:09:36+00:00

When routing a packet to a LAN behind a peer, ovpn needs to inspect the route entry that brought the packet there in the first place. If this packet is truly routable, the route entry provides the GW to be used when looking up the VPN peer to send the packet to. However, the route entry is currently dropped before entering the ovpn xmit function, because the IFF_XMIT_DST_RELEASE priv_flag is enabled by default. Clear the IFF_XMIT_DST_RELEASE flag during interface setup to allow the route entry (skb's dst) to survive and thus be inspected by the ovpn routing logic. Fixes: a3aaef8cd173 ("ovpn: implement peer lookup logic") Reported-by: Gert Doering Closes: https://github.com/OpenVPN/ovpn-net-next/issues/2 Tested-by: Gert Doering Acked-by: Gert Doering # as a primary user Link: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg31583.html Signed-off-by: Antonio Quartulli

ovpn: add basic ethtool support

2025-04-17T10:30:03+00:00

Implement support for basic ethtool functionality. Note that ovpn is a virtual device driver, therefore various ethtool APIs are just not meaningful and thus not implemented. Signed-off-by: Antonio Quartulli Reviewed-by: Andrew Lunn Link: https://patch.msgid.link/20250415-b4-ovpn-v26-22-577f6097b964@openvpn.net Reviewed-by: Sabrina Dubroca Tested-by: Oleksandr Natalenko Signed-off-by: Paolo Abeni

ovpn: implement keepalive mechanism

2025-04-17T10:30:03+00:00

OpenVPN supports configuring a periodic keepalive packet. message to allow the remote endpoint detect link failures. This change implements the keepalive sending and timer expiring logic. Signed-off-by: Antonio Quartulli Link: https://patch.msgid.link/20250415-b4-ovpn-v26-16-577f6097b964@openvpn.net Reviewed-by: Sabrina Dubroca Tested-by: Oleksandr Natalenko Signed-off-by: Paolo Abeni

ovpn: implement multi-peer support

2025-04-17T10:30:03+00:00

With this change an ovpn instance will be able to stay connected to multiple remote endpoints. This functionality is strictly required when running ovpn on an OpenVPN server. Signed-off-by: Antonio Quartulli Link: https://patch.msgid.link/20250415-b4-ovpn-v26-14-577f6097b964@openvpn.net Reviewed-by: Sabrina Dubroca Tested-by: Oleksandr Natalenko Signed-off-by: Paolo Abeni

ovpn: implement TCP transport

2025-04-17T10:30:03+00:00

With this change ovpn is allowed to communicate to peers also via TCP. Parsing of incoming messages is implemented through the strparser API. Note that ovpn redefines sk_prot and sk_socket->ops for the TCP socket used to communicate with the peer. For this reason it needs to access inet6_stream_ops, which is declared as extern in the IPv6 module, but it is not fully exported. Therefore this patch is also adding EXPORT_SYMBOL_GPL(inet6_stream_ops) to net/ipv6/af_inet6.c. Cc: David Ahern Cc: Eric Dumazet Cc: Jakub Kicinski Cc: Paolo Abeni Cc: Simon Horman Signed-off-by: Antonio Quartulli Link: https://patch.msgid.link/20250415-b4-ovpn-v26-11-577f6097b964@openvpn.net Reviewed-by: Sabrina Dubroca Tested-by: Oleksandr Natalenko Signed-off-by: Paolo Abeni

ovpn: implement basic RX path (UDP)

2025-04-17T10:30:02+00:00

Packets received over the socket are forwarded to the user device. Implementation is UDP only. TCP will be added by a later patch. Note: no decryption/decapsulation exists yet, packets are forwarded as they arrive without much processing. Signed-off-by: Antonio Quartulli Link: https://patch.msgid.link/20250415-b4-ovpn-v26-8-577f6097b964@openvpn.net Reviewed-by: Sabrina Dubroca Tested-by: Oleksandr Natalenko Signed-off-by: Paolo Abeni

ovpn: introduce the ovpn_socket object

2025-04-17T10:30:02+00:00

This specific structure is used in the ovpn kernel module to wrap and carry around a standard kernel socket. ovpn takes ownership of passed sockets and therefore an ovpn specific objects is attached to them for status tracking purposes. Initially only UDP support is introduced. TCP will come in a later patch. Cc: willemdebruijn.kernel@gmail.com Signed-off-by: Antonio Quartulli Link: https://patch.msgid.link/20250415-b4-ovpn-v26-6-577f6097b964@openvpn.net Reviewed-by: Sabrina Dubroca Tested-by: Oleksandr Natalenko Signed-off-by: Paolo Abeni