kernel/linux.git/net/openvswitch/vport-netdev.c, branch v6.6.131

openvswitch: defer tunnel netdev_put to RCU release

2026-04-02T11:07:17+00:00

[ Upstream commit 6931d21f87bc6d657f145798fad0bf077b82486c ] ovs_netdev_tunnel_destroy() may run after NETDEV_UNREGISTER already detached the device. Dropping the netdev reference in destroy can race with concurrent readers that still observe vport->dev. Do not release vport->dev in ovs_netdev_tunnel_destroy(). Instead, let vport_netdev_free() drop the reference from the RCU callback, matching the non-tunnel destroy path and avoiding additional synchronization under RTNL. Fixes: a9020fde67a6 ("openvswitch: Move tunnel destroy function to oppenvswitch module.") Reported-by: Yifan Wu Reported-by: Juefei Pu Tested-by: Ao Zhou Co-developed-by: Yuan Tan Signed-off-by: Yuan Tan Suggested-by: Xin Liu Signed-off-by: Yang Yang Reviewed-by: Ilya Maximets Link: https://patch.msgid.link/20260319074241.3405262-1-n05ec@lzu.edu.cn Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net: openvswitch: Avoid releasing netdev before teardown completes

2026-04-02T11:07:17+00:00

[ Upstream commit 7c770dadfda5cbbde6aa3c4363ed513f1d212bf8 ] The patch cited in the Fixes tag below changed the teardown code for OVS ports to no longer unconditionally take the RTNL. After this change, the netdev_destroy() callback can proceed immediately to the call_rcu() invocation if the IFF_OVS_DATAPATH flag is already cleared on the netdev. The ovs_netdev_detach_dev() function clears the flag before completing the unregistration, and if it gets preempted after clearing the flag (as can happen on an -rt kernel), netdev_destroy() can complete and the device can be freed before the unregistration completes. This leads to a splat like: [ 998.393867] Oops: general protection fault, probably for non-canonical address 0xff00000001000239: 0000 [#1] SMP PTI [ 998.393877] CPU: 42 UID: 0 PID: 55177 Comm: ip Kdump: loaded Not tainted 6.12.0-211.1.1.el10_2.x86_64+rt #1 PREEMPT_RT [ 998.393886] Hardware name: Dell Inc. PowerEdge R740/0JMK61, BIOS 2.24.0 03/27/2025 [ 998.393889] RIP: 0010:dev_set_promiscuity+0x8d/0xa0 [ 998.393901] Code: 00 00 75 d8 48 8b 53 08 48 83 ba b0 02 00 00 00 75 ca 48 83 c4 08 5b c3 cc cc cc cc 48 83 bf 48 09 00 00 00 75 91 48 8b 47 08 <48> 83 b8 b0 02 00 00 00 74 97 eb 81 0f 1f 80 00 00 00 00 90 90 90 [ 998.393906] RSP: 0018:ffffce5864a5f6a0 EFLAGS: 00010246 [ 998.393912] RAX: ff00000000ffff89 RBX: ffff894d0adf5a05 RCX: 0000000000000000 [ 998.393917] RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffff894d0adf5a05 [ 998.393921] RBP: ffff894d19252000 R08: ffff894d19252000 R09: 0000000000000000 [ 998.393924] R10: ffff894d19252000 R11: ffff894d192521b8 R12: 0000000000000006 [ 998.393927] R13: ffffce5864a5f738 R14: 00000000ffffffe2 R15: 0000000000000000 [ 998.393931] FS: 00007fad61971800(0000) GS:ffff894cc0140000(0000) knlGS:0000000000000000 [ 998.393936] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 998.393940] CR2: 000055df0a2a6e40 CR3: 000000011c7fe003 CR4: 00000000007726f0 [ 998.393944] PKRU: 55555554 [ 998.393946] Call Trace: [ 998.393949] [ 998.393952] ? show_trace_log_lvl+0x1b0/0x2f0 [ 998.393961] ? show_trace_log_lvl+0x1b0/0x2f0 [ 998.393975] ? dp_device_event+0x41/0x80 [openvswitch] [ 998.394009] ? __die_body.cold+0x8/0x12 [ 998.394016] ? die_addr+0x3c/0x60 [ 998.394027] ? exc_general_protection+0x16d/0x390 [ 998.394042] ? asm_exc_general_protection+0x26/0x30 [ 998.394058] ? dev_set_promiscuity+0x8d/0xa0 [ 998.394066] ? ovs_netdev_detach_dev+0x3a/0x80 [openvswitch] [ 998.394092] dp_device_event+0x41/0x80 [openvswitch] [ 998.394102] notifier_call_chain+0x5a/0xd0 [ 998.394106] unregister_netdevice_many_notify+0x51b/0xa60 [ 998.394110] rtnl_dellink+0x169/0x3e0 [ 998.394121] ? rt_mutex_slowlock.constprop.0+0x95/0xd0 [ 998.394125] rtnetlink_rcv_msg+0x142/0x3f0 [ 998.394128] ? avc_has_perm_noaudit+0x69/0xf0 [ 998.394130] ? __pfx_rtnetlink_rcv_msg+0x10/0x10 [ 998.394132] netlink_rcv_skb+0x50/0x100 [ 998.394138] netlink_unicast+0x292/0x3f0 [ 998.394141] netlink_sendmsg+0x21b/0x470 [ 998.394145] ____sys_sendmsg+0x39d/0x3d0 [ 998.394149] ___sys_sendmsg+0x9a/0xe0 [ 998.394156] __sys_sendmsg+0x7a/0xd0 [ 998.394160] do_syscall_64+0x7f/0x170 [ 998.394162] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 998.394165] RIP: 0033:0x7fad61bf4724 [ 998.394188] Code: 89 02 b8 ff ff ff ff eb bb 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 80 3d c5 e9 0c 00 00 74 13 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 48 83 ec 28 89 54 24 1c 48 89 [ 998.394189] RSP: 002b:00007ffd7e2f7cb8 EFLAGS: 00000202 ORIG_RAX: 000000000000002e [ 998.394191] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007fad61bf4724 [ 998.394193] RDX: 0000000000000000 RSI: 00007ffd7e2f7d20 RDI: 0000000000000003 [ 998.394194] RBP: 00007ffd7e2f7d90 R08: 0000000000000010 R09: 000000000000003f [ 998.394195] R10: 000055df11558010 R11: 0000000000000202 R12: 00007ffd7e2f8380 [ 998.394196] R13: 0000000069b233d7 R14: 000055df0a256040 R15: 0000000000000000 [ 998.394200] To fix this, reorder the operations in ovs_netdev_detach_dev() to only clear the flag after completing the other operations, and introduce an smp_wmb() to make the ordering requirement explicit. The smp_wmb() is paired with a full smp_mb() in netdev_destroy() to make sure the call_rcu() invocation does not happen before the unregister operations are visible. Reported-by: Minxi Hou Tested-by: Minxi Hou Fixes: 549822767630 ("net: openvswitch: Avoid needlessly taking the RTNL on vport destroy") Signed-off-by: Toke Høiland-Jørgensen Link: https://patch.msgid.link/20260318155554.1133405-1-toke@redhat.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net: openvswitch: Avoid needlessly taking the RTNL on vport destroy

2026-01-11T14:22:06+00:00

[ Upstream commit 5498227676303e3ffa9a3a46214af96bc3e81314 ] The openvswitch teardown code will immediately call ovs_netdev_detach_dev() in response to a NETDEV_UNREGISTER notification. It will then start the dp_notify_work workqueue, which will later end up calling the vport destroy() callback. This callback takes the RTNL to do another ovs_netdev_detach_port(), which in this case is unnecessary. This causes extra pressure on the RTNL, in some cases leading to "unregister_netdevice: waiting for XX to become free" warnings on teardown. We can straight-forwardly avoid the extra RTNL lock acquisition by checking the device flags before taking the lock, and skip the locking altogether if the IFF_OVS_DATAPATH flag has already been unset. Fixes: b07c26511e94 ("openvswitch: fix vport-netdev unregister") Tested-by: Adrian Moreno Signed-off-by: Toke Høiland-Jørgensen Acked-by: Eelco Chaudron Acked-by: Aaron Conole Link: https://patch.msgid.link/20251211115006.228876-1-toke@redhat.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

rtnetlink: Honour NLM_F_ECHO flag in rtnl_delete_link

2022-11-01T01:10:21+00:00

This patch use the new helper unregister_netdevice_many_notify() for rtnl_delete_link(), so that the kernel could reply unicast when userspace set NLM_F_ECHO flag to request the new created interface info. At the same time, the parameters of rtnl_delete_link() need to be updated since we need nlmsghdr and portid info. Suggested-by: Guillaume Nault Signed-off-by: Hangbin Liu Reviewed-by: Guillaume Nault Signed-off-by: Jakub Kicinski

net: rename reference+tracking helpers

2022-06-10T04:52:55+00:00

Netdev reference helpers have a dev_ prefix for historic reasons. Renaming the old helpers would be too much churn but we can rename the tracking ones which are relatively recent and should be the default for new code. Rename: dev_hold_track() -> netdev_hold() dev_put_track() -> netdev_put() dev_replace_track() -> netdev_ref_replace() Link: https://lore.kernel.org/r/20220608043955.919359-1-kuba@kernel.org Signed-off-by: Jakub Kicinski

openvswitch: add net device refcount tracker to struct vport

2021-12-08T04:45:00+00:00

Signed-off-by: Eric Dumazet Signed-off-by: Jakub Kicinski

net: openvswitch: Remove redundant if statements

2021-12-02T13:08:19+00:00

The 'if (dev)' statement already move into dev_{put , hold}, so remove redundant if statements. Signed-off-by: Xu Wang Signed-off-by: David S. Miller

net: openvswitch: Use 'skb_push_rcsum()' instead of hand coding it

2021-04-04T08:43:02+00:00

'skb_push()'/'skb_postpush_rcsum()' can be replaced by an equivalent 'skb_push_rcsum()' which is less verbose. Signed-off-by: Christophe JAILLET Signed-off-by: David S. Miller

net: openvswitch: use netif_ovs_is_port() instead of opencode

2019-07-08T22:53:25+00:00

Use netif_ovs_is_port() function instead of open code. This patch doesn't change logic. Signed-off-by: Taehee Yoo Signed-off-by: David S. Miller

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 269

2019-06-05T15:30:29+00:00

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of version 2 of the gnu general public license as published by the free software foundation this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 51 franklin street fifth floor boston ma 02110 1301 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 21 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Alexios Zavras Reviewed-by: Allison Randal Reviewed-by: Richard Fontana Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141334.228102212@linutronix.de Signed-off-by: Greg Kroah-Hartman