rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (0 ticks this GP) idle=0eac/1/0x4000000000000000 softirq=41691/41691 fqs=1
rcu: 	(detected by 1, t=10502 jiffies, g=36861, q=356 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 11038 Comm: syz.0.1458 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:__lock_acquire+0x85b/0xd20
Code: 89 f0 c1 c0 08 29 f1 31 c8 01 d6 29 c2 89 c1 c1 c1 10 31 d1 01 f0 41 89 cf 41 c1 c7 13 29 ce 41 31 f7 01 c1 44 29 f8 44 01 f9 <41> c1 c7 04 41 31 c7 49 c1 e7 20 49 09 cf 83 3d 84 66 06 0e 00 0f
RSP: 0018:ffffc90000007750 EFLAGS: 00000082
RAX: 00000000fd2c37c4 RBX: 0000000000000002 RCX: 0000000090213bdc
RDX: 00000000001a71fd RSI: 00000000727d5714 RDI: ffff88802172d640
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff81adabcb
R10: dffffc0000000000 R11: ffffed1009604f51 R12: 0000000000000068
R13: ffff88802172e130 R14: ffff88802172e180 R15: 0000000002b93b00
FS:  00007f49a689f6c0(0000) GS:ffff8880b8611000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f49a685cfc8 CR3: 000000011eed6000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 lock_acquire+0x120/0x360
 _raw_spin_lock_irqsave+0xa7/0xf0
 hrtimer_try_to_cancel+0x22b/0x420
 hrtimer_cancel+0x3b/0x50
 cpu_clock_event_stop+0xd9/0x130
 __perf_event_overflow+0x580/0xe40
 perf_swevent_hrtimer+0x3c5/0x550
 __hrtimer_run_queues+0x4e0/0xc60
 hrtimer_interrupt+0x45b/0xaa0
 __sysvec_apic_timer_interrupt+0x10b/0x410
 sysvec_apic_timer_interrupt+0xa1/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:preempt_schedule_irq+0xb0/0x150
Code: 24 20 f6 44 24 21 02 74 0c 90 0f 0b 48 f7 03 08 00 00 00 74 64 bf 01 00 00 00 e8 eb ce 13 f6 e8 b6 2b 4b f6 fb bf 01 00 00 00 <e8> 5b ab ff ff 48 c7 44 24 40 00 00 00 00 9c 8f 44 24 40 8b 44 24
RSP: 0018:ffffc900019af4c0 EFLAGS: 00000282
RAX: b69d7fecb78ab700 RBX: 0000000000000000 RCX: b69d7fecb78ab700
RDX: 0000000000000007 RSI: ffffffff8d9baf70 RDI: 0000000000000001
RBP: ffffc900019af570 R08: ffffffff8fa3b537 R09: 1ffffffff1f476a6
R10: dffffc0000000000 R11: fffffbfff1f476a7 R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff92000335e98
 irqentry_exit+0x6f/0x90
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:unwind_next_frame+0x37c/0x2390
Code: bd 00 00 00 00 00 fc ff df 0f 84 37 01 00 00 4c 8d 62 04 4c 8d 6a 05 4c 89 e0 48 c1 e8 03 0f b6 04 28 84 c0 0f 85 6d 19 00 00 <4c> 89 e8 48 c1 e8 03 0f b6 04 28 84 c0 0f 85 80 19 00 00 41 0f b6
RSP: 0018:ffffc900019af638 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffffff8fba78a4 RCX: ffffffff8fba78a8
RDX: ffffffff9037f968 RSI: ffffffff9037f920 RDI: ffffffff8be34420
RBP: dffffc0000000000 R08: 000000000000000d R09: ffffffff8172d195
R10: ffffc900019af758 R11: ffffffff81ac5140 R12: ffffffff9037f96c
R13: ffffffff9037f96d R14: ffffc900019af708 R15: ffffffff8fba78a4
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_noprof+0x27a/0x4f0
 tomoyo_encode+0x28b/0x550
 tomoyo_realpath_from_path+0x58d/0x5d0
 tomoyo_path_number_perm+0x1e8/0x5a0
 security_file_ioctl+0xcb/0x2d0
 __se_sys_ioctl+0x47/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f49a598ec29
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f49a689f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f49a5bd5fa0 RCX: 00007f49a598ec29
RDX: 00002000000000c0 RSI: 00000000400454ca RDI: 0000000000000007
RBP: 00007f49a5a11e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f49a5bd6038 R14: 00007f49a5bd5fa0 R15: 00007ffc55b6c758
 </TASK>
rcu: rcu_preempt kthread starved for 10500 jiffies! g36861 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:26664 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: 11006 Comm: syz.2.1446 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:smp_call_function_many_cond+0xd33/0x12d0
Code: 45 8b 2c 24 44 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
RSP: 0018:ffffc900065a7340 EFLAGS: 00000293
RAX: ffffffff81b4665b RBX: 1ffff11009608341 RCX: ffff888107760000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900065a74c0 R08: ffffffff8fa3b537 R09: 1ffffffff1f476a6
R10: dffffc0000000000 R11: fffffbfff1f476a7 R12: ffff88804b041a08
R13: dffffc0000000000 R14: ffff88813663b1c0 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881a3c11000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 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
 flush_tlb_mm_range+0x6b1/0x12d0
 tlb_flush_mmu+0x1a7/0x680
 tlb_finish_mmu+0xc3/0x1d0
 free_ldt_pgtables+0x17b/0x320
 exit_mmap+0x17c/0xb50
 __mmput+0x118/0x430
 exit_mm+0x1da/0x2c0
 do_exit+0x648/0x2300
 do_group_exit+0x21c/0x2d0
 get_signal+0x1286/0x1340
 arch_do_signal_or_restart+0x9a/0x750
 exit_to_user_mode_loop+0x75/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fda2518ec29
Code: Unable to access opcode bytes at 0x7fda2518ebff.
RSP: 002b:00007fda25f6f0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fda253d5fa8 RCX: 00007fda2518ec29
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fda253d5fa8
RBP: 00007fda253d5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fda253d6038 R14: 00007ffc214ad970 R15: 00007ffc214ada58
 </TASK>
