FYI, we noticed the below changes on

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
commit 7412301b76bd53ee53b860f611fc3b5b1c2245b5 ("Smack: Assign smack_known_web as default smk_in label for kernel thread's socket")


+----------------------------------+------------+------------+
|                                  | 74f0414b2f | 7412301b76 |
+----------------------------------+------------+------------+
| boot_successes                   | 8          | 0          |
| boot_failures                    | 0          | 8          |
| INFO:suspicious_RCU_usage        | 0          | 8          |
| backtrace:inet_ctl_sock_create   | 0          | 8          |
| backtrace:dccp_v4_init_net       | 0          | 8          |
| backtrace:ops_init               | 0          | 8          |
| backtrace:register_pernet_subsys | 0          | 8          |
| backtrace:dccp_v4_init           | 0          | 8          |
| backtrace:kernel_init_freeable   | 0          | 8          |
| invoked_oom-killer:gfp_mask=0x   | 0          | 1          |
| Mem-Info                         | 0          | 1          |
| Out_of_memory:Kill_process       | 0          | 1          |
| backtrace:vfs_writev             | 0          | 1          |
| backtrace:SyS_writev             | 0          | 1          |
+----------------------------------+------------+------------+



[   22.152970] DCCP: Activated CCID 2 (TCP-like)
[   22.164997] 
[   22.165505] ===============================
[   22.166384] [ INFO: suspicious RCU usage. ]
[   22.167268] 4.0.0-rc1-00004-g7412301 #1 Not tainted
[   22.168266] -------------------------------
[   22.169154] net/ipv4/cipso_ipv4.c:1936 suspicious rcu_dereference_protected() usage!
[   22.171025] 
[   22.171025] other info that might help us debug this:
[   22.171025] 
[   22.172994] 
[   22.172994] rcu_scheduler_active = 1, debug_locks = 0
[   22.174397] 3 locks held by swapper/0/1:
[   22.175260]  #0:  (net_mutex){+.+.+.}, at: [<c21327ea>] register_pernet_subsys+0x25/0x67
[   22.177432]  #1:  (slock-AF_INET/1){+.....}, at: [<c17fe59b>] smack_netlabel+0x53/0xff
[   22.179575]  #2:  (rcu_read_lock){......}, at: [<c24cc6e4>] netlbl_sock_setattr+0x0/0x284
[   22.181678] 
[   22.181678] stack backtrace:
[   22.182729] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.0.0-rc1-00004-g7412301 #1
[   22.184267] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014
[   22.185948]  00000000 00000000 d326bdd8 c2595e9d 00000001 d326bdf4 c110de36 c2bbda2a
[   22.188179]  d32e0000 cde48000 cdd920fb cdd92e10 d326be18 c2274f3f 0000000b 0000000c
[   22.190362]  cdd920f0 cdd92e10 ffffffa7 c2e490f8 00000002 d326be30 c24cc866 cde48000
[   22.192585] Call Trace:
[   22.193197]  [<c2595e9d>] dump_stack+0xb8/0x108
[   22.194090]  [<c110de36>] lockdep_rcu_suspicious+0x1eb/0x202
[   22.195138]  [<c2274f3f>] cipso_v4_sock_setattr+0x17c/0x282
[   22.196221]  [<c24cc866>] netlbl_sock_setattr+0x182/0x284
[   22.197240]  [<c17fe5fd>] smack_netlabel+0xb5/0xff
[   22.198166]  [<c17fe6c5>] smack_socket_post_create+0x7e/0x8f
[   22.199212]  [<c17fa048>] security_socket_post_create+0x29/0x3c
[   22.200342]  [<c21161e0>] __sock_create+0x3cb/0x515
[   22.201296]  [<c211639e>] sock_create_kern+0x2a/0x3a
[   22.202252]  [<c2233e29>] inet_ctl_sock_create+0x33/0x88
[   22.203251]  [<c3155384>] dccp_v4_init_net+0x42/0x5a
[   22.204248]  [<c2131c52>] ops_init+0x270/0x2b2
[   22.205277]  [<c2233505>] ? inet_register_protosw+0x1d9/0x1fe
[   22.206341]  [<c2131d55>] register_pernet_operations+0xc1/0x13d
[   22.207507]  [<c315539c>] ? dccp_v4_init_net+0x5a/0x5a
[   22.208532]  [<c21327ff>] register_pernet_subsys+0x3a/0x67
[   22.223269]  [<c315543a>] dccp_v4_init+0x9e/0x112
[   22.224242]  [<c3090a32>] do_one_initcall+0x227/0x358
[   22.225211]  [<c10a6bac>] ? __usermodehelper_set_disable_depth+0x65/0x79
[   22.226399]  [<c3090f40>] kernel_init_freeable+0x3dd/0x55e
[   22.227418]  [<c3090f40>] ? kernel_init_freeable+0x3dd/0x55e
[   22.228509]  [<c2585c2c>] kernel_init+0x1b/0x1ec
[   22.229425]  [<c25b5b01>] ret_from_kernel_thread+0x21/0x30
[   22.230450]  [<c2585c11>] ? rest_init+0x274/0x274
[   22.253519] tipc: Activated (version 2.0.0)
[   22.257814] NET: Registered protocol family 30
[   22.275239] tipc: Started in single node mode


Thanks,
Ying Huang