Comment 34 for bug 1376245

uname -a
Linux amber 3.13.0-39-generic #66~precise1-Ubuntu SMP Wed Oct 29 09:56:49 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

In dmesg i see this message every time (but system is not crashes)

[56757.172197] ------------[ cut here ]------------
[56757.172222] WARNING: CPU: 1 PID: 12934 at /build/buildd/linux-lts-trusty-3.13.0/fs/proc/generic.c:511 remove_proc_entry+0x13a/0x1b0()
[56757.172226] name 'fs/nfsfs'
[56757.172230] Modules linked in: vhost_net macvtap macvlan vhost ip6table_filter ip6_tables ebtable_nat ebtables kvm_amd kvm xt_tcpudp xt_nat xt_conntrack iptable_mangle iptable_nat nf_nat_ipv4 nf_nat iptable_filter ip_tables x_tables nf_conntrack_ftp nf_conntrack_ipv4 nf_conntrack nf_defrag_ipv4 bridge 8021q mrp garp stp radeon llc ttm drm_kms_helper drm ch341 usbserial psmouse serio_raw sp5100_tco edac_core i2c_piix4 i2c_algo_bit edac_mce_amd k8temp shpchp asus_atk0110 mac_hid nfsd nfs_acl auth_rpcgss nfs fscache lockd sunrpc lp parport hid_generic usbhid hid pata_acpi raid10 raid456 async_pq async_xor async_memcpy async_raid6_recov async_tx raid1 raid0 multipath linear btrfs pata_atiixp r8169 ahci mii raid6_pq libahci xor libcrc32c
[56757.172356] CPU: 1 PID: 12934 Comm: kworker/u8:2 Tainted: G W 3.13.0-39-generic #66~precise1-Ubuntu
[56757.172362] Hardware name: System manufacturer System Product Name/M2A-VM, BIOS ASUS M2A-VM ACPI BIOS Revision 1604 12/19/2007
[56757.172372] Workqueue: netns cleanup_net
[56757.172377] 00000000000001ff ffff880019c87c08 ffffffff81755f65 0000000000000007
[56757.172387] ffff880019c87c58 ffff880019c87c48 ffffffff8106afcc 0000000000000013
[56757.172394] 0000000000000000 0000000000000005 ffff8800754189b0 ffff880019c87db8
[56757.172401] Call Trace:
[56757.172416] [<ffffffff81755f65>] dump_stack+0x46/0x58
[56757.172427] [<ffffffff8106afcc>] warn_slowpath_common+0x8c/0xc0
[56757.172438] [<ffffffff8106b0b6>] warn_slowpath_fmt+0x46/0x50
[56757.172447] [<ffffffff81236faa>] remove_proc_entry+0x13a/0x1b0
[56757.172456] [<ffffffff811adb94>] ? kfree+0x134/0x170
[56757.172499] [<ffffffffa02695c6>] nfs_fs_proc_net_exit+0x66/0x80 [nfs]
[56757.172522] [<ffffffffa026f696>] nfs_net_exit+0x16/0x30 [nfs]
[56757.172531] [<ffffffff816467c8>] ops_exit_list.isra.1+0x38/0x60
[56757.172539] [<ffffffff816470c2>] cleanup_net+0x112/0x230
[56757.172548] [<ffffffff8108797f>] process_one_work+0x17f/0x4c0
[56757.172555] [<ffffffff81088b9b>] worker_thread+0x11b/0x3d0
[56757.172562] [<ffffffff81088a80>] ? manage_workers.isra.21+0x190/0x190
[56757.172569] [<ffffffff8108fb29>] kthread+0xc9/0xe0
[56757.172576] [<ffffffff8108fa60>] ? flush_kthread_worker+0xb0/0xb0
[56757.172583] [<ffffffff8176b5bc>] ret_from_fork+0x7c/0xb0
[56757.172589] [<ffffffff8108fa60>] ? flush_kthread_worker+0xb0/0xb0
[56757.172594] ---[ end trace a39f667ba5f1c01f ]---