kernel/linux.git/drivers/net/ovpn/peer.c, branch v7.2-rc5

ovpn: use monotonic clock for peer keepalive timeouts

2026-07-20T14:29:31+00:00

Replace ktime_get_real_seconds() with the monotonic ktime_get_boottime_seconds() to ensure the keepalive mechanism is robust against system clock modifications. Right now, the driver uses ktime_get_real_seconds() to track peer timeouts, relying on the system wall-clock. An administrative time adjustment or an NTP sync that steps the clock forward can cause `now' to instantly exceed `last_recv + timeout'. When this occurs, the driver artificially expires healthy peers. Depending on the OpenVPN user-space configuration, this triggers a premature tunnel restart (if --keepalive or --ping-restart is used) or a complete disconnection of the client (if --ping-exit is used). Fixes: 3ecfd9349f40 ("ovpn: implement keepalive mechanism") Signed-off-by: Marco Baffo Signed-off-by: Antonio Quartulli

ovpn: fix use after free in unlock_ovpn()

2026-07-20T13:49:55+00:00

unlock_ovpn() iterates over the release_list using llist_for_each_entry() and drops the peer reference inside the loop body via ovpn_peer_put(). If this drops the last reference, the peer is eventually freed. However, llist_for_each_entry() reads peer->release_entry.next in the loop advance expression, which runs after the body. By that time the peer may have already been freed, resulting in a use after free when advancing to the next list entry. Fix this by using llist_for_each_entry_safe(), which caches the next pointer before executing the loop body. Fixes: 80747caef33d ("ovpn: introduce the ovpn_peer object") Signed-off-by: Marco Baffo Signed-off-by: Antonio Quartulli

ovpn: hold peer before scheduling keepalive work

2026-07-20T13:49:55+00:00

ovpn_peer_keepalive_send() passes its peer reference to ovpn_xmit_special(), which ultimately drops it. The keepalive scheduler currently queues the work first and takes the reference only after schedule_work() reports that the work was queued. Once schedule_work() queues the item, another CPU may run the worker before the caller gets to ovpn_peer_hold(). In that case the worker can consume a reference that was not acquired for it, corrupting the peer lifetime accounting. Take the peer reference before queueing the work and drop it again when the work was already pending. Fixes: 3ecfd9349f40 ("ovpn: implement keepalive mechanism") Cc: stable@vger.kernel.org Signed-off-by: Shuvam Pandey Reviewed-by: Sabrina Dubroca Signed-off-by: Antonio Quartulli

ovpn: avoid putting unrelated P2P peer on socket release

2026-07-20T13:49:55+00:00

ovpn_peer_release_p2p() is called when an OVPN UDP socket is being destroyed. It checks the currently published P2P peer and releases it only if that peer still uses the socket being destroyed. A peer replacement can publish a new peer before the old UDP socket is destroyed. When the old socket destruction path runs afterwards, ovpn_peer_release_p2p() observes the new peer through ovpn->peer. Since the new peer uses a different socket, the function takes the socket mismatch branch. That branch still calls ovpn_peer_put(peer). At this point, however, peer is the currently published replacement peer, not the peer associated with the socket being destroyed. Dropping its reference can free it while ovpn->peer still points to it, leading to later use-after-free accesses from the peer and socket cleanup paths. KASAN reports this as a slab-use-after-free on the kmalloc-1k ovpn_peer object. In the reproducer, the object is allocated from ovpn_peer_new() via ovpn_nl_peer_new_doit(), and freed through ovpn_peer_release_rcu() from RCU callback processing. Observed access sites include ovpn_peer_remove(), ovpn_socket_release(), ovpn_nl_peer_del_notify(), and unlock_ovpn(). Fix this by returning from the socket mismatch branch without putting the peer. Fixes: f6226ae7a0cd ("ovpn: introduce the ovpn_socket object") Signed-off-by: Qing Ming Reviewed-by: Simon Horman Signed-off-by: Antonio Quartulli

ovpn: fix race between deleting interface and adding new peer

2026-05-14T14:24:45+00:00

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

ovpn: respect peer refcount in CMD_NEW_PEER error path

2026-05-14T14:24:45+00:00

ovpn_nl_peer_new_doit()'s error path calls ovpn_peer_release() directly rather than ovpn_peer_put(), bypassing the kref. The accompanying comment ("peer was not yet hashed, thus it is not used in any context") holds for UDP but not for TCP. For UDP, the ovpn_socket union uses the .ovpn arm and never points back at a peer; UDP encap_recv looks up peers via the not-yet-populated hashtables, so the new peer is unreachable until ovpn_peer_add() publishes it. For TCP, ovpn_socket_new() sets ovpn_sock->peer and ovpn_tcp_socket_attach() publishes ovpn_sock via rcu_assign_sk_user_data(). From that moment until ovpn_socket_release() detaches in the error path, the TCP fd is fully wired: userspace recvmsg / sendmsg / close / poll on the fd, as well as the strparser-driven ovpn_tcp_rcv() path, can reach the peer through sk_user_data -> ovpn_sock->peer and bump its refcount via ovpn_peer_hold(). ovpn_tcp_socket_wait_finish() (called inside ovpn_socket_release()) drains strparser and the tx work, but does not synchronize with userspace syscall callers that already hold a peer reference. If ovpn_nl_peer_modify() or ovpn_peer_add() returns an error while such a caller is in flight - notably an ovpn_tcp_recvmsg() blocked in __skb_recv_datagram() on peer->tcp.user_queue - the direct ovpn_peer_release() destroys the peer while the caller still holds the reference, and the eventual ovpn_peer_put() from that caller operates on freed memory. Replace the direct destructor call with ovpn_peer_put() so the kref correctly defers destruction until the last reference is dropped. In the common case where no concurrent user is present, behaviour is unchanged: the kref hits zero immediately and ovpn_peer_release_kref() runs the same destructor. With this conversion ovpn_peer_release() has no callers outside peer.c - ovpn_peer_release_kref() in the same translation unit is the only remaining user - so make it static and drop its declaration from peer.h. Fixes: 11851cbd60ea ("ovpn: implement TCP transport") Reviewed-by: Sabrina Dubroca Assisted-by: Claude:claude-opus-4-7 Signed-off-by: David Carlier Signed-off-by: Antonio Quartulli

drivers: net: drop ipv6_stub usage and use direct function calls

2026-03-29T18:21:23+00:00

As IPv6 is built-in only, the ipv6_stub infrastructure is no longer necessary. Convert all drivers currently utilizing ipv6_stub to make direct function calls. The fallback functions introduced previously will prevent linkage errors when CONFIG_IPV6 is disabled. Signed-off-by: Fernando Fernandez Mancera Tested-by: Ricardo B. Marlière Reviewed-by: Jason A. Donenfeld Reviewed-by: Antonio Quartulli Reviewed-by: Edward Cree Link: https://patch.msgid.link/20260325120928.15848-7-fmancera@suse.de Signed-off-by: Jakub Kicinski

ovpn: add support for asymmetric peer IDs

2026-03-17T10:09:05+00:00

In order to support the multipeer architecture, upon connection setup each side of a tunnel advertises a unique ID that the other side must include in packets sent to them. Therefore when transmitting a packet, a peer inserts the recipient's advertised ID for that specific tunnel into the peer ID field. When receiving a packet, a peer expects to find its own unique receive ID for that specific tunnel in the peer ID field. Add support for the TX peer ID and embed it into transmitting packets. If no TX peer ID is specified, fallback to using the same peer ID both for RX and TX in order to be compatible with the non-multipeer compliant peers. Cc: horms@kernel.org Cc: donald.hunter@gmail.com Signed-off-by: Ralf Lici Signed-off-by: Antonio Quartulli Reviewed-by: Sabrina Dubroca

ovpn: notify userspace on client float event

2026-03-17T10:08:55+00:00

Send a netlink notification when a client updates its remote UDP endpoint. The notification includes the new IP address, port, and scope ID (for IPv6). Cc: linux-kselftest@vger.kernel.org Cc: horms@kernel.org Cc: shuah@kernel.org Cc: donald.hunter@gmail.com Signed-off-by: Ralf Lici Signed-off-by: Antonio Quartulli Reviewed-by: Sabrina Dubroca

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 '\