rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P11035/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=39365, q=985 ncpus=2)
task:syz.3.1315      state:R  running task     stack:26872 pid:11035 tgid:11033 ppid:6708   task_flags:0x400140 flags:0x00004000
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 preempt_schedule_irq+0xb5/0x150
 irqentry_exit+0x6f/0x90
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:unwind_next_frame+0x199a/0x2390
Code: 74 28 80 3d 40 8a 1a 0e 00 75 1f c6 05 37 8a 1a 0e 01 48 c7 c7 a0 41 88 8b be 66 03 00 00 48 c7 c2 40 42 88 8b e8 e6 af 2a 00 <48> c7 c7 20 a1 13 8e 4c 89 fe e8 c7 95 2a 00 e8 52 41 34 00 89 d8
RSP: 0018:ffffc90007407298 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffffff90341701 RCX: 4200c86d0a521b00
RDX: ffffc90007407301 RSI: ffffffff8be34260 RDI: ffffffff8be34220
RBP: dffffc0000000000 R08: ffffc90007407c10 R09: 0000000000000000
R10: ffffc900074073b8 R11: fffff52000e80e79 R12: ffffc90007407c20
R13: ffffc90007400000 R14: ffffc90007407368 R15: ffffffff8172d195
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_node_track_caller_noprof+0x271/0x4e0
 kstrdup+0x42/0x100
 alloc_vfsmnt+0xeb/0x430
 clone_mnt+0x67/0xae0
 copy_tree+0x3d4/0x930
 copy_mnt_ns+0x179/0x880
 create_new_namespaces+0xd1/0x720
 copy_namespaces+0x438/0x4b0
 copy_process+0x1733/0x3c00
 kernel_clone+0x21e/0x840
 __x64_sys_clone+0x18b/0x1e0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f567598ec29
RSP: 002b:00007f5676816fe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f5675bd5fa0 RCX: 00007f567598ec29
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000022023400
RBP: 00007f5675a11e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f5675bd6038 R14: 00007f5675bd5fa0 R15: 00007ffff8e12248
 </TASK>
rcu: rcu_preempt kthread starved for 10495 jiffies! g39365 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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  running task     stack:26728 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_timeout+0x12b/0x270
 rcu_gp_fqs_loop+0x301/0x1540
 rcu_gp_kthread+0x99/0x390
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 7540 Comm: kworker/u10:13 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+0xd38/0x12d0
Code: 89 ee 83 e6 01 31 ff e8 b6 63 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 61 5f 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 45 5f 0b 00 eb e4 44
RSP: 0018:ffffc90002e3f660 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 1ffff11009608341 RCX: ffff8881093f8000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90002e3f7e0 R08: ffffffff8fa3b237 R09: 1ffffffff1f47646
R10: dffffc0000000000 R11: fffffbfff1f47647 R12: ffff88804b041a08
R13: dffffc0000000000 R14: ffff88813663b1c0 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881a3c12000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f56767f5fc8 CR3: 000000000df36000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80
 smp_text_poke_batch_finish+0x5f9/0x1130
 arch_jump_label_transform_apply+0x1c/0x30
 static_key_enable_cpuslocked+0x128/0x250
 static_key_enable+0x1a/0x20
 toggle_allocation_gate+0xad/0x240
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
