rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 0, t=10502 jiffies, g=69709, q=337 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294988327-4294977825), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g69709 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=23937
rcu: rcu_preempt kthread starved for 10502 jiffies! g69709 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200 ->cpu=1
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R stack:27776 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 __schedule+0x15dd/0x5300
 schedule+0x164/0x360
 schedule_timeout+0x158/0x2c0
 rcu_gp_fqs_loop+0x312/0x11d0
 rcu_gp_kthread+0x9e/0x2b0
 kthread+0x388/0x470
 ret_from_fork+0x51e/0xb90
 ret_from_fork_asm+0x1a/0x30
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 12822 Comm: syz.8.1543 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:mm_get_cid+0xc0/0x160
Code: 13 44 89 f0 5b 41 5c 41 5d 41 5e 41 5f 5d e9 17 de 18 0a cc 49 c7 c5 98 5e 1b 8e 49 c1 ed 03 eb 07 44 89 f0 f7 d8 71 d9 f3 90 <43> 0f b6 44 25 00 84 c0 75 59 44 8b 3d e7 46 85 0c e8 aa 30 51 03
RSP: 0018:ffffc9000693fc10 EFLAGS: 00000887
RAX: 0000000080000000 RBX: ffff88810432be10 RCX: dffffc0000000000
RDX: ffffc9000923a000 RSI: 0000000000000002 RDI: ffff88810432bf10
RBP: ffff88816ad3b348 R08: 1ffff11020865681 R09: 0000000000000000
R10: ffff88810432b554 R11: fffff52000d27f78 R12: dffffc0000000000
R13: 1ffffffff1c36bd3 R14: 0000000080000000 R15: 0000000000000002
FS:  00007f1c4e7396c0(0000) GS:ffff8882a9463000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3060dff8 CR3: 00000001118b6000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 sched_mm_cid_fork+0x3f6/0xdf0
 bprm_execve+0xda1/0x1460
 do_execveat_common+0x50d/0x690
 __x64_sys_execveat+0xc7/0xf0
 do_syscall_64+0x14d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1c4d79c799
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f1c4e739028 EFLAGS: 00000246 ORIG_RAX: 0000000000000142
RAX: ffffffffffffffda RBX: 00007f1c4da15fa0 RCX: 00007f1c4d79c799
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000004
RBP: 00007f1c4d832c99 R08: 0000000000001000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1c4da16038 R14: 00007f1c4da15fa0 R15: 00007fffacc0e008
 </TASK>
