WARN_ON triggered net/netlink/af_netlink.c:374 netlink_sock_destruct+0x118/0x140

Folks,

Somewhere between 4.13.0-rc2 and 4.13.0-rc6-next-20170825 I started
getting about 50 warnings on boot from:
	net/netlink/af_netlink.c:netlink_sock_destruct():
	"WARN_ON(atomic_read(&sk->sk_rmem_alloc));"

(gcc version 4.8.2 20140120 (Red Hat 4.8.2-15) (GCC))

Config is attached.

------------[ cut here ]------------
WARNING: CPU: 1 PID: 80 at net/netlink/af_netlink.c:374 netlink_sock_destruct+0x118/0x140
Modules linked in:
CPU: 1 PID: 80 Comm: systemd-fstab-g Not tainted 4.13.0-rc6-next-20170825-ghak16-audit-BPRM_FCAPS-record.v4_2+ #595
Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2007
task: ffff88003aaf2a40 task.stack: ffffc90000414000
RIP: 0010:netlink_sock_destruct+0x118/0x140
RSP: 0000:ffff88003e403e38 EFLAGS: 00010202
RAX: 0000000000000300 RBX: ffff880037341000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff820323d0
RBP: ffff88003e403e48 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 000000002cdaa52d R12: 0000000000000001
R13: ffff88003e403f08 R14: 000000000000000a R15: ffff88003aaf2a40
FS:  0000000000000000(0000) GS:ffff88003e400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055e444891018 CR3: 0000000036c28000 CR4: 00000000000006e0
Call Trace:
 <IRQ>
 __sk_destruct+0x2a/0x270
 ? netlink_getsockopt+0x350/0x350
 sk_destruct+0x20/0x30
 __sk_free+0x94/0xd0
 sk_free+0x1e/0x20
 deferred_put_nlk_sk+0x91/0xa0
 rcu_process_callbacks+0x37f/0x890
 ? rcu_process_callbacks+0x345/0x890
 __do_softirq+0xd9/0x50a
 irq_exit+0xe5/0xf0
 smp_apic_timer_interrupt+0x3d/0x50
 apic_timer_interrupt+0x9d/0xb0
 </IRQ>
RIP: 0010:lock_acquire+0xec/0x220
RSP: 0000:ffffc900004179d8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10
RAX: ffff88003aaf2a40 RBX: 0000000000000246 RCX: 000000009cabfcb2
RDX: 0000000000000002 RSI: 0000000049c42d85 RDI: 0000000000000246
RBP: ffffc90000417a38 R08: ffff88003aaf33c0 R09: ffff88003aaf3380
R10: 0000000000000000 R11: 00000000f21c2c78 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000
 ? alloc_set_pte+0x34d/0x660
 _raw_spin_lock+0x3d/0x80
 ? alloc_set_pte+0x34d/0x660
 alloc_set_pte+0x34d/0x660
 finish_fault+0x62/0xa0
 __handle_mm_fault+0xe24/0x12b0
 handle_mm_fault+0xe2/0x160
 __do_page_fault+0x3d7/0x770
 do_page_fault+0x22/0x30
 page_fault+0x22/0x30
RIP: 0010:__clear_user+0x42/0x70
RSP: 0000:ffffc90000417d10 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 00000000000001fd RCX: 00000000000001fd
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 000055e444891018
RBP: ffffc90000417d20 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000013bf810d R12: 000055e444891018
R13: 0000000000000001 R14: 000055e444892000 R15: 00007ffffffff000
 clear_user+0xd8/0x110
 padzero+0x24/0x40
 load_elf_binary+0x830/0x1718
 ? do_raw_read_unlock+0x30/0x60
 search_binary_handler+0x97/0x1d0
 do_execveat_common.isra.33+0x6b2/0xa10
 ? do_execveat_common.isra.33+0x5ee/0xa10
 SyS_execve+0x3a/0x50
 do_syscall_64+0x82/0x2b0
 entry_SYSCALL64_slow_path+0x25/0x25
RIP: 0033:0x7f55c77abbd7
RSP: 002b:00007fff70c10658 EFLAGS: 00000206 ORIG_RAX: 000000000000003b
RAX: ffffffffffffffda RBX: 00000000055d4a80 RCX: 00007f55c77abbd7
RDX: 00007fff70c10ae8 RSI: 00007fff70c106f0 RDI: 00005604154dd5e0
RBP: 00007fff70c106e0 R08: 00007f55c9222940 R09: 00007f55c7cc2280
R10: 00007f55c7cc62f0 R11: 0000000000000206 R12: 00005604154dd5e0
R13: 0000000000000000 R14: 00005604154d54a0 R15: 00007f55c9222740
Code: db 89 de e8 3b 20 9a ff 85 db 75 17 31 c9 31 d2 89 de 48 c7 c7 e0 22 03 82 e8 25 20 9a ff 5b 41 5c 5d c3 0f ff eb e5 0f ff eb aa <0f> ff 66 0f 1f 44 00 00 e9 63 ff ff ff 48 89 de 48 c7 c7 b8 19 
---[ end trace d783a8a3612e8c22 ]---

- RGB

--
Richard Guy Briggs [off-list ref]
Sr. S/W Engineer, Kernel Security, Base Operating Systems
Remote, Ottawa, Red Hat Canada
IRC: rgb, SunRaycer
Voice: +1.647.777.2635, Internal: (81) 32635