linux/net/openvswitch
Ilya Maximets aa69918bd4 openvswitch: vport: fix self-deadlock on release of tunnel ports
vports are used concurrently and protected by RCU, so netdev_put()
must happen after the RCU grace period.  So, either in an RCU call or
after the synchronize_net().  The rtnl_delete_link() must happen under
RTNL and so can't be executed in RCU context.  Calling synchronize_net()
while holding RTNL is not a good idea for performance and system
stability under load in general, so calling netdev_put() in RCU call
is the right solution here.

However,
when the device is deleted, rtnl_unlock() will call netdev_run_todo()
and block until all the references are gone.  In the current code this
means that we never reach the call_rcu() and the vport is never freed
and the reference is never released, causing a self-deadlock on device
removal.

Fix that by moving the rcu_call() before the rtnl_unlock(), so the
scheduled RCU callback will be executed when synchronize_net() is
called from the rtnl_unlock()->netdev_run_todo() while the RTNL itself
is already released.

Fixes: 6931d21f87 ("openvswitch: defer tunnel netdev_put to RCU release")
Cc: stable@vger.kernel.org
Acked-by: Eelco Chaudron <echaudro@redhat.com>
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
Acked-by: Aaron Conole <aconole@redhat.com>
Link: https://patch.msgid.link/20260430233848.440994-2-i.maximets@ovn.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-05-05 15:19:37 +02:00
..
actions.c net: convert remaining ipv6_stub users to direct function calls 2026-03-29 11:21:23 -07:00
conntrack.c Convert more 'alloc_obj' cases to default GFP_KERNEL arguments 2026-02-21 20:03:00 -08:00
conntrack.h net/sched: act_api: fix miss set post_ct for ovs after do conntrack in act_ct 2021-03-16 15:22:18 -07:00
datapath.c openvswitch: cap upcall PID array size and pre-size vport replies 2026-04-20 11:43:04 -07:00
datapath.h net: openvswitch: allow providing upcall pid for the 'execute' command 2025-07-07 14:30:39 -07:00
dp_notify.c net: replace use of system_wq with system_percpu_wq 2025-09-22 17:40:30 -07:00
drop.h net: openvswitch: add misc error drop reasons 2023-08-14 08:01:06 +01:00
flow_netlink.c openvswitch: validate MPLS set/set_masked payload length 2026-03-20 18:37:31 -07:00
flow_netlink.h net: openvswitch: remove never-working support for setting nsh fields 2025-11-14 18:13:24 -08:00
flow_table.c net: use get_random_u{16,32,64}() where appropriate 2026-04-09 19:27:43 -07:00
flow_table.h net: openvswitch: Annotate struct mask_array with __counted_by 2023-10-17 13:56:03 +02:00
flow.c net: openvswitch: Use for_each_cpu() where appropriate 2025-08-20 19:47:22 -07:00
flow.h net: openvswitch: reduce cpu_used_mask memory 2023-02-06 22:36:29 -08:00
Kconfig sctp: use skb_crc32c() instead of __skb_checksum() 2025-05-21 15:40:16 -07:00
Makefile openvswitch: add trace points 2021-06-22 10:47:32 -07:00
meter.c Convert 'alloc_flex' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
meter.h net: openvswitch: remove unnecessary linux/genetlink.h include 2024-04-01 21:44:34 -07:00
openvswitch_trace.c openvswitch: add trace points 2021-06-22 10:47:32 -07:00
openvswitch_trace.h tracing/treewide: Remove second parameter of __assign_str() 2024-05-22 20:14:47 -04:00
vport-geneve.c openvswitch: vport: fix race between tunnel creation and linking 2026-05-05 15:14:33 +02:00
vport-gre.c openvswitch: vport: fix race between tunnel creation and linking 2026-05-05 15:14:33 +02:00
vport-internal_dev.c net: rename netns_local to netns_immutable 2025-03-04 12:44:48 +01:00
vport-internal_dev.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 269 2019-06-05 17:30:29 +02:00
vport-netdev.c openvswitch: vport: fix self-deadlock on release of tunnel ports 2026-05-05 15:19:37 +02:00
vport-netdev.h openvswitch: vport: fix race between tunnel creation and linking 2026-05-05 15:14:33 +02:00
vport-vxlan.c openvswitch: vport: fix race between tunnel creation and linking 2026-05-05 15:14:33 +02:00
vport.c openvswitch: cap upcall PID array size and pre-size vport replies 2026-04-20 11:43:04 -07:00
vport.h net: openvswitch: fix kernel-doc warnings in internal headers 2025-03-24 09:30:21 -07:00