rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 0, t=10502 jiffies, g=131725, q=411 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295005637-4294995135), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g131725 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=37501
rcu: rcu_preempt kthread starved for 10502 jiffies! g131725 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:27536 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 __schedule+0x17b4/0x5680
 schedule+0x164/0x360
 schedule_timeout+0x158/0x2c0
 rcu_gp_fqs_loop+0x312/0x11d0
 rcu_gp_kthread+0x9e/0x2b0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 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: 20048 Comm: syz.2.2036 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:sched_mm_cid_fork+0x657/0x10e0
Code: c7 03 00 00 00 40 e9 19 01 00 00 49 c7 c4 b8 4e 26 8e 49 c1 ec 03 41 bd 00 00 00 80 eb 0a 89 e8 f7 d8 0f 81 09 fe ff ff f3 90 <48> b8 00 00 00 00 00 fc ff df 41 0f b6 04 04 84 c0 75 40 44 8b 35
RSP: 0018:ffffc90008dffc48 EFLAGS: 00000887
RAX: 0000000080000000 RBX: ffff88810d2cd510 RCX: 0000000080000001
RDX: dffffc0000000000 RSI: 0000000000000002 RDI: ffff88810d2cd510
RBP: 0000000080000000 R08: 1ffff11021a59951 R09: 0000000000000000
R10: ffff88810d2ccbcc R11: fffff520011bff78 R12: 1ffffffff1c4c9d7
R13: 0000000080000000 R14: 0000000000000002 R15: ffff88810d2cc980
FS:  00007f650f63e6c0(0000) GS:ffff8882a9290000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c320421 CR3: 000000010cb3a000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 bprm_execve+0xdb7/0x1440
 do_execveat_common+0x50d/0x690
 __x64_sys_execveat+0xc7/0xf0
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f650e79cdd9
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:00007f650f63e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000142
RAX: ffffffffffffffda RBX: 00007f650ea15fa0 RCX: 00007f650e79cdd9
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000004
RBP: 00007f650e832d69 R08: 0000000000001000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f650ea16038 R14: 00007f650ea15fa0 R15: 00007fff462766f8
 </TASK>
