kernel/linux.git/drivers/net/wireguard, branch v6.18.35

wireguard: send: append trailer after expanding head

2026-06-09T10:28:40+00:00

commit f75e3eb08fe31d30a9af6ed80cdd22e6772837e2 upstream. With how this is currently written, we add the trailer, zero it out, and then add the header space on. If that header space requires a reallocation + copy, the zeros in the trailer aren't copied, because the skb len hasn't actually been yet expanded to cover that. Instead add the padding at the end of the process rather than at the beginning. Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") Cc: stable@vger.kernel.org Signed-off-by: Jason A. Donenfeld Link: https://patch.msgid.link/20260529173134.3080773-2-Jason@zx2c4.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

wireguard: device: use exit_rtnl callback instead of manual rtnl_lock in pre_exit

2026-04-22T11:22:33+00:00

commit 60a25ef8dacb3566b1a8c4de00572a498e2a3bf9 upstream. wg_netns_pre_exit() manually acquires rtnl_lock() inside the pernet .pre_exit callback. This causes a hung task when another thread holds rtnl_mutex - the cleanup_net workqueue (or the setup_net failure rollback path) blocks indefinitely in wg_netns_pre_exit() waiting to acquire the lock. Convert to .exit_rtnl, introduced in commit 7a60d91c690b ("net: Add ->exit_rtnl() hook to struct pernet_operations."), where the framework already holds RTNL and batches all callbacks under a single rtnl_lock()/rtnl_unlock() pair, eliminating the contention window. The rcu_assign_pointer(wg->creating_net, NULL) is safe to move from .pre_exit to .exit_rtnl (which runs after synchronize_rcu()) because all RCU readers of creating_net either use maybe_get_net() - which returns NULL for a dying namespace with zero refcount - or access net->user_ns which remains valid throughout the entire ops_undo_list sequence. Reported-by: syzbot+f2fbf7478a35a94c8b7c@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?id=cb64c22a492202ca929e18262fdb8cb89e635c70 Signed-off-by: Shardul Bankar [ Jason: added __net_exit and __read_mostly annotations that were missing. ] Fixes: 900575aa33a3 ("wireguard: device: avoid circular netns references") Cc: stable@vger.kernel.org Signed-off-by: Jason A. Donenfeld Link: https://patch.msgid.link/20260414153944.2742252-5-Jason@zx2c4.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

net: WQ_PERCPU added to alloc_workqueue users

2025-09-23T00:40:30+00:00

Currently if a user enqueue a work item using schedule_delayed_work() the used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to schedule_work() that is using system_wq and queue_work(), that makes use again of WORK_CPU_UNBOUND. This lack of consistentcy cannot be addressed without refactoring the API. alloc_workqueue() treats all queues as per-CPU by default, while unbound workqueues must opt-in via WQ_UNBOUND. This default is suboptimal: most workloads benefit from unbound queues, allowing the scheduler to place worker threads where they’re needed and reducing noise when CPUs are isolated. This change adds a new WQ_PERCPU flag at the network subsystem, to explicitly request the use of the per-CPU behavior. Both flags coexist for one release cycle to allow callers to transition their calls. Once migration is complete, WQ_UNBOUND can be removed and unbound will become the implicit default. With the introduction of the WQ_PERCPU flag (equivalent to !WQ_UNBOUND), any alloc_workqueue() caller that doesn’t explicitly specify WQ_UNBOUND must now use WQ_PERCPU. All existing users have been updated accordingly. Suggested-by: Tejun Heo Signed-off-by: Marco Crivellari Link: https://patch.msgid.link/20250918142427.309519-4-marco.crivellari@suse.com Signed-off-by: Jakub Kicinski

wireguard: queueing: always return valid online CPU in wg_cpumask_choose_online()

2025-09-12T01:52:21+00:00

The function gets number of online CPUS, and uses it to search for Nth cpu in cpu_online_mask. If id == num_online_cpus() - 1, and one CPU gets offlined between calling num_online_cpus() -> cpumask_nth(), there's a chance for cpumask_nth() to find nothing and return >= nr_cpu_ids. The caller code in __queue_work() tries to avoid that by checking the returned CPU against WORK_CPU_UNBOUND, which is NR_CPUS. It's not the same as '>= nr_cpu_ids'. On a typical Ubuntu desktop, NR_CPUS is 8192, while nr_cpu_ids is the actual number of possible CPUs, say 8. The non-existing cpu may later be passed to rcu_dereference() and corrupt the logic. Fix it by switching from 'if' to 'while'. Suggested-by: Jason A. Donenfeld Signed-off-by: Yury Norov (NVIDIA) Signed-off-by: Jason A. Donenfeld Link: https://patch.msgid.link/20250910013644.4153708-3-Jason@zx2c4.com Signed-off-by: Jakub Kicinski

wireguard: queueing: simplify wg_cpumask_next_online()

2025-09-12T01:52:20+00:00

wg_cpumask_choose_online() opencodes cpumask_nth(). Use it and make the function significantly simpler. While there, fix opencoded cpu_online() too. Signed-off-by: Yury Norov Reviewed-by: Simon Horman Signed-off-by: Jason A. Donenfeld Link: https://patch.msgid.link/20250910013644.4153708-2-Jason@zx2c4.com Signed-off-by: Jakub Kicinski

wireguard: peer: Replace sockaddr with sockaddr_inet

2025-07-25T22:29:58+00:00

As part of the removal of the variably-sized sockaddr for kernel internals, replace struct sockaddr with sockaddr_inet in the endpoint union. No binary changes; the union size remains unchanged due to sockaddr_inet matching the size of sockaddr_in6. Signed-off-by: Kees Cook Link: https://patch.msgid.link/20250722171836.1078436-2-kees@kernel.org Signed-off-by: Jakub Kicinski

net: Use netif_threaded_enable instead of netif_set_threaded in drivers

2025-07-25T01:34:55+00:00

Prepare for adding an enum type for NAPI threaded states by adding netif_threaded_enable API. De-export the existing netif_set_threaded API and only use it internally. Update existing drivers to use netif_threaded_enable instead of the de-exported netif_set_threaded. Note that dev_set_threaded used by mt76 debugfs file is unchanged. Signed-off-by: Samiullah Khawaja Link: https://patch.msgid.link/20250723013031.2911384-3-skhawaja@google.com Signed-off-by: Jakub Kicinski

net: s/dev_set_threaded/netif_set_threaded/

2025-07-19T00:27:47+00:00

Commit cc34acd577f1 ("docs: net: document new locking reality") introduced netif_ vs dev_ function semantics: the former expects locked netdev, the latter takes care of the locking. We don't strictly follow this semantics on either side, but there are more dev_xxx handlers now that don't fit. Rename them to netif_xxx where appropriate. Note that one dev_set_threaded call still remains in mt76 for debugfs file. Signed-off-by: Stanislav Fomichev Link: https://patch.msgid.link/20250717172333.1288349-7-sdf@fomichev.me Signed-off-by: Jakub Kicinski

net: ipv6: Add a flags argument to ip6tunnel_xmit(), udp_tunnel6_xmit_skb()

2025-06-18T01:18:45+00:00

ip6tunnel_xmit() erases the contents of the SKB control block. In order to be able to set particular IP6CB flags on the SKB, add a corresponding parameter, and propagate it to udp_tunnel6_xmit_skb() as well. In one of the following patches, VXLAN driver will use this facility to mark packets as subject to IPv6 multicast routing. Signed-off-by: Petr Machata Reviewed-by: Ido Schimmel Reviewed-by: Nikolay Aleksandrov Link: https://patch.msgid.link/acb4f9f3e40c3a931236c3af08a720b017fbfbfb.1750113335.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski

net: ipv4: Add a flags argument to iptunnel_xmit(), udp_tunnel_xmit_skb()

2025-06-18T01:18:44+00:00

iptunnel_xmit() erases the contents of the SKB control block. In order to be able to set particular IPCB flags on the SKB, add a corresponding parameter, and propagate it to udp_tunnel_xmit_skb() as well. In one of the following patches, VXLAN driver will use this facility to mark packets as subject to IP multicast routing. Signed-off-by: Petr Machata Reviewed-by: Ido Schimmel Reviewed-by: Nikolay Aleksandrov Acked-by: Antonio Quartulli Link: https://patch.msgid.link/89c9daf9f2dc088b6b92ccebcc929f51742de91f.1750113335.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski