From: Nicolas Dichtel <nicolas.dichtel@xxxxxxxxx> commit c95c5f58b35ef995f66cb55547eee6093ab5fcb8 upstream. Here is the steps to reproduce the problem: ip netns add foo ip netns add bar ip -n foo link add xfrmi0 type xfrm dev lo if_id 42 ip -n foo link set xfrmi0 netns bar ip netns del foo ip netns del bar Which results to: [ 186.686395] general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6bd3: 0000 [#1] SMP PTI [ 186.687665] CPU: 7 PID: 232 Comm: kworker/u16:2 Not tainted 5.6.0+ #1 [ 186.688430] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 [ 186.689420] Workqueue: netns cleanup_net [ 186.689903] RIP: 0010:xfrmi_dev_uninit+0x1b/0x4b [xfrm_interface] [ 186.690657] Code: 44 f6 ff ff 31 c0 5b 5d 41 5c 41 5d 41 5e c3 48 8d 8f c0 08 00 00 8b 05 ce 14 00 00 48 8b 97 d0 08 00 00 48 8b 92 c0 0e 00 00 <48> 8b 14 c2 48 8b 02 48 85 c0 74 19 48 39 c1 75 0c 48 8b 87 c0 08 [ 186.692838] RSP: 0018:ffffc900003b7d68 EFLAGS: 00010286 [ 186.693435] RAX: 000000000000000d RBX: ffff8881b0f31000 RCX: ffff8881b0f318c0 [ 186.694334] RDX: 6b6b6b6b6b6b6b6b RSI: 0000000000000246 RDI: ffff8881b0f31000 [ 186.695190] RBP: ffffc900003b7df0 R08: ffff888236c07740 R09: 0000000000000040 [ 186.696024] R10: ffffffff81fce1b8 R11: 0000000000000002 R12: ffffc900003b7d80 [ 186.696859] R13: ffff8881edcc6a40 R14: ffff8881a1b6e780 R15: ffffffff81ed47c8 [ 186.697738] FS: 0000000000000000(0000) GS:ffff888237dc0000(0000) knlGS:0000000000000000 [ 186.698705] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 186.699408] CR2: 00007f2129e93148 CR3: 0000000001e0a000 CR4: 00000000000006e0 [ 186.700221] Call Trace: [ 186.700508] rollback_registered_many+0x32b/0x3fd [ 186.701058] ? __rtnl_unlock+0x20/0x3d [ 186.701494] ? arch_local_irq_save+0x11/0x17 [ 186.702012] unregister_netdevice_many+0x12/0x55 [ 186.702594] default_device_exit_batch+0x12b/0x150 [ 186.703160] ? prepare_to_wait_exclusive+0x60/0x60 [ 186.703719] cleanup_net+0x17d/0x234 [ 186.704138] process_one_work+0x196/0x2e8 [ 186.704652] worker_thread+0x1a4/0x249 [ 186.705087] ? cancel_delayed_work+0x92/0x92 [ 186.705620] kthread+0x105/0x10f [ 186.706000] ? __kthread_bind_mask+0x57/0x57 [ 186.706501] ret_from_fork+0x35/0x40 [ 186.706978] Modules linked in: xfrm_interface nfsv3 nfs_acl auth_rpcgss nfsv4 nfs lockd grace fscache sunrpc button parport_pc parport serio_raw evdev pcspkr loop ext4 crc16 mbcache jbd2 crc32c_generic 8139too ide_cd_mod cdrom ide_gd_mod ata_generic ata_piix libata scsi_mod piix psmouse i2c_piix4 ide_core 8139cp i2c_core mii floppy [ 186.710423] ---[ end trace 463bba18105537e5 ]--- The problem is that x-netns xfrm interface are not removed when the link netns is removed. This causes later this oops when thoses interfaces are removed. Let's add a handler to remove all interfaces related to a netns when this netns is removed. Fixes: f203b76d7809 ("xfrm: Add virtual xfrm interfaces") Reported-by: Christophe Gouault <christophe.gouault@xxxxxxxxx> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@xxxxxxxxx> Signed-off-by: Steffen Klassert <steffen.klassert@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/xfrm/xfrm_interface.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) --- a/net/xfrm/xfrm_interface.c +++ b/net/xfrm/xfrm_interface.c @@ -750,7 +750,28 @@ static struct rtnl_link_ops xfrmi_link_o .get_link_net = xfrmi_get_link_net, }; +static void __net_exit xfrmi_exit_batch_net(struct list_head *net_exit_list) +{ + struct net *net; + LIST_HEAD(list); + + rtnl_lock(); + list_for_each_entry(net, net_exit_list, exit_list) { + struct xfrmi_net *xfrmn = net_generic(net, xfrmi_net_id); + struct xfrm_if __rcu **xip; + struct xfrm_if *xi; + + for (xip = &xfrmn->xfrmi[0]; + (xi = rtnl_dereference(*xip)) != NULL; + xip = &xi->next) + unregister_netdevice_queue(xi->dev, &list); + } + unregister_netdevice_many(&list); + rtnl_unlock(); +} + static struct pernet_operations xfrmi_net_ops = { + .exit_batch = xfrmi_exit_batch_net, .id = &xfrmi_net_id, .size = sizeof(struct xfrmi_net), };