rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (0 ticks this GP) idle=b7cc/1/0x4000000000000000 softirq=62345/62351 fqs=1
rcu: 	(detected by 1, t=10505 jiffies, g=42681, q=534 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5293 Comm: udevd 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:its_return_thunk+0x0/0x10
Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc <c3> cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 e9 6b 13 b7 f5 cc
RSP: 0018:ffffc90000007390 EFLAGS: 00000006
RAX: ffffffff81ade57e RBX: ffff88810666d340 RCX: ffff888024ce8000
RDX: 0000000000010100 RSI: 0000000000000000 RDI: ffff88810666d340
RBP: ffffc90000007508 R08: ffff88810666d357 R09: 0000000000000000
R10: ffff88810666d340 R11: ffffed1020ccda6b R12: ffff88810666d340
R13: dffffc0000000000 R14: 1877385750000000 R15: ffff88804b027c80
FS:  00007f93110eac80(0000) GS:ffff8880b861b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f64447ecd58 CR3: 0000000020b7a000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 debug_deactivate+0xe/0x200
 __hrtimer_run_queues+0x2b0/0xc60
 hrtimer_interrupt+0x45b/0xaa0
 __sysvec_apic_timer_interrupt+0x10b/0x410
 sysvec_apic_timer_interrupt+0x52/0xc0
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:unwind_next_frame+0x11a/0x2390
Code: 01 48 c7 c7 e0 3e 88 8b be 4b 03 00 00 48 c7 c2 20 3f 88 8b e8 a7 c3 2a 00 4c 89 6c 24 70 48 89 5c 24 68 4d 8d 6e 50 4c 89 e8 <48> c1 e8 03 48 89 44 24 38 80 3c 28 00 74 08 4c 89 ef e8 5f 52 b0
RSP: 0018:ffffc90000007738 EFLAGS: 00000246
RAX: ffffc90000007858 RBX: ffffffff8232f524 RCX: 405cb39908869e00
RDX: 0000000000000000 RSI: ffffffff8be33660 RDI: ffffffff8be33620
RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90000007858 R11: ffffffff81ac3810 R12: 1ffff92000000f01
R13: ffffc90000007858 R14: ffffc90000007808 R15: ffffffff8172c195
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5b/0x80
 slab_free_after_rcu_debug+0x129/0x2a0
 rcu_core+0xcab/0x1770
 handle_softirqs+0x286/0x870
 __irq_exit_rcu+0xca/0x1f0
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:__kmalloc_noprof+0x6a/0x4f0
Code: 67 03 00 00 f7 c5 11 00 40 00 0f 85 65 03 00 00 45 31 f6 41 8d 4f ff 49 81 ff c0 00 00 00 77 0c c1 e9 03 0f b6 81 10 f8 bd 8d <eb> 0a b8 ff ff ff ff 0f bd c1 ff c0 89 c3 83 f8 0e 0f 83 5a 03 00
RSP: 0018:ffffc9000273f4f0 EFLAGS: 00000206
RAX: 0000000000000006 RBX: ffff88801fd4afd6 RCX: 0000000000000006
RDX: ffff888024ce8000 RSI: 0000000000000d40 RDI: 0000000000000032
RBP: 0000000000000d40 R08: ffff88801fd4afd6 R09: 0000000000000fd6
R10: ffff88801fd4afd6 R11: 0000000000000fd6 R12: ffff88801fd4affc
R13: 0000000000000027 R14: 0000000000000000 R15: 0000000000000032
 tomoyo_encode+0x28b/0x550
 tomoyo_realpath_from_path+0x58d/0x5d0
 tomoyo_check_open_permission+0x1c1/0x3b0
 security_file_open+0xb1/0x270
 do_dentry_open+0x384/0x13f0
 vfs_open+0x3b/0x340
 path_openat+0x2ee5/0x3830
 do_filp_open+0x1fa/0x410
 do_sys_openat2+0x121/0x1c0
 __x64_sys_openat+0x138/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9310d169a4
Code: 24 20 48 8d 44 24 30 48 89 44 24 28 64 8b 04 25 18 00 00 00 85 c0 75 2c 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 76 60 48 8b 15 55 a4 0d 00 f7 d8 64 89 02 48 83
RSP: 002b:00007ffd052b4c70 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 00007f9310d169a4
RDX: 0000000000080000 RSI: 00007ffd052b4da8 RDI: 00000000ffffff9c
RBP: 00007ffd052b4da8 R08: 0000000000000008 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000080000
R13: 000055d8f8d97b42 R14: 0000000000000001 R15: 0000000000000000
 </TASK>
rcu: rcu_preempt kthread starved for 10500 jiffies! g42681 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:27496 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+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 6202 Comm: kworker/u10:4 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+0xd33/0x12d0
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 b6 62 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 61 5e 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 5e
RSP: 0018:ffffc90004f67660 EFLAGS: 00000293
RAX: ffffffff81b44ceb RBX: 1ffff11009608341 RCX: ffff888105dd3980
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90004f677e0 R08: ffffffff8fa38337 R09: 1ffffffff1f47066
R10: dffffc0000000000 R11: fffffbfff1f47067 R12: ffff88804b041a08
R13: dffffc0000000000 R14: ffff88813663b1c0 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881a3c1b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c31585e CR3: 000000000df36000 CR4: 00000000000006f0
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+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
