rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (0 ticks this GP) idle=516c/1/0x4000000000000000 softirq=15895/15895 fqs=1
rcu: 	(detected by 0, t=10502 jiffies, g=10357, q=414 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6221 Comm: syz.1.77 Not tainted syzkaller #0 PREEMPT(full) 
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+0x5b0/0x1120
Code: 00 00 31 ed 31 db e9 7b 01 00 00 49 c7 c4 98 4e 1b 8e 49 c1 ec 03 41 bd 00 00 00 80 eb 0a 89 e8 f7 d8 0f 81 e3 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:ffffc90007817c48 EFLAGS: 00000887
RAX: 0000000080000000 RBX: ffff8881b952d510 RCX: 0000000080000001
RDX: dffffc0000000000 RSI: 0000000000000002 RDI: ffff8881b952d510
RBP: 0000000080000000 R08: 1ffff110372a5951 R09: 0000000000000000
R10: ffff8881b952cbd4 R11: fffff52000f02f78 R12: 1ffffffff1c369d3
R13: 0000000080000000 R14: 0000000000000002 R15: ffff8881b952c980
FS:  00007fdff2c286c0(0000) GS:ffff8882a9465000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdff1e4eddd CR3: 000000016e890000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 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: 0033:0x7fdff1d9c799
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:00007fdff2c28028 EFLAGS: 00000246 ORIG_RAX: 0000000000000142
RAX: ffffffffffffffda RBX: 00007fdff2015fa0 RCX: 00007fdff1d9c799
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000004
RBP: 00007fdff1e32c99 R08: 0000000000001000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdff2016038 R14: 00007fdff2015fa0 R15: 00007ffc3dfaf088
 </TASK>
rcu: rcu_preempt kthread starved for 10495 jiffies! g10357 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
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  running task     stack:28120 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 __schedule+0x15dd/0x52d0
 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:
CPU: 0 UID: 0 PID: 1096 Comm: kworker/u9:5 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:smp_call_function_many_cond+0xcfd/0x12c0
Code: 00 00 00 00 fc ff df 75 07 e8 6f e2 0b 00 eb 38 f3 90 42 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 53 e2 0b 00 <eb> e4 44 89 e1 80 e1 07 80 c1 03 38 c1 7c e2 4c 89 e7 e8 0c 18 75
RSP: 0018:ffffc9000693f700 EFLAGS: 00000293
RAX: ffffffff81b9b18d RBX: 1ffff110478c811d RCX: ffff8881067a1d40
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000693f840 R08: ffffffff9011dab7 R09: 1ffffffff2023b56
R10: dffffc0000000000 R11: fffffbfff2023b57 R12: ffff88823c6408e8
R13: dffffc0000000000 R14: ffff88812103bf00 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff88818de65000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdff1de9e80 CR3: 000000000e54c000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80
 smp_text_poke_batch_finish+0x5f5/0x1160
 arch_jump_label_transform_apply+0x1c/0x30
 static_key_enable_cpuslocked+0x128/0x240
 static_key_enable+0x1a/0x20
 toggle_allocation_gate+0xab/0x290
 process_scheduled_works+0xb6e/0x18c0
 worker_thread+0xa53/0xfc0
 kthread+0x388/0x470
 ret_from_fork+0x51e/0xb90
 ret_from_fork_asm+0x1a/0x30
 </TASK>
