rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (0 ticks this GP) idle=124c/1/0x4000000000000000 softirq=47501/47501 fqs=0
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P7307/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=36057, q=345 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 11011 Comm: syz.6.1451 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:hrtimer_try_to_cancel+0x1f/0x420
Code: 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 30 48 89 fb 49 be 00 00 00 00 00 fc ff df <e8> dc 1b 12 00 48 8d 4b 38 48 89 5c 24 18 48 83 c3 30 48 89 d8 48
RSP: 0018:ffffc90000007928 EFLAGS: 00000086
RAX: ffffffff81adabe1 RBX: ffff8880399752a8 RCX: ffff8881078b8000
RDX: 0000000000010000 RSI: 0000000000000004 RDI: ffff8880399752a8
RBP: 00000000ffffffff R08: ffff88804b027a83 R09: 1ffff11009604f50
R10: dffffc0000000000 R11: ffffed1009604f51 R12: ffff888039975350
R13: dffffc0000000000 R14: dffffc0000000000 R15: ffffffffffff26a1
FS:  00007f760ee246c0(0000) GS:ffff8880b8612000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f760ee23fc8 CR3: 0000000037522000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000082
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 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:__sanitizer_cov_trace_const_cmp8+0x18/0x90
Code: 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 08 e0 a0 92 65 8b 15 d8 19 e1 10 <81> e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 57 83 b9 3c 16 00 00
RSP: 0018:ffffc9000a397e88 EFLAGS: 00000257
RAX: ffffffff8234ff20 RBX: ffff888027251c00 RCX: ffff8881078b8000
RDX: 0000000080000001 RSI: 0000000000000000 RDI: ffffffffffffffff
RBP: 0000000000000000 R08: ffff888027251d67 R09: 1ffff11004e4a3ac
R10: dffffc0000000000 R11: ffffed1004e4a3ad R12: 0000000000002402
R13: ffffffff81f2e9d0 R14: ffff888027251d60 R15: 0000000000000001
 fput+0x50/0xd0
 __se_sys_ioctl+0x168/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f760df8ec29
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:00007f760ee24038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f760e1d5fa0 RCX: 00007f760df8ec29
RDX: 0000000000000001 RSI: 0000000000002402 RDI: 0000000000000004
RBP: 00007f760e011e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f760e1d6038 R14: 00007f760e1d5fa0 R15: 00007ffd7e4d68f8
 </TASK>
task:syz-executor    state:R  running task     stack:21480 pid:7307  tgid:7307  ppid:7306   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:lock_acquire+0x175/0x360
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 7b 6f 03 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc9000328f5f8 EFLAGS: 00000206
RAX: e110631f40400c00 RBX: 0000000000000000 RCX: e110631f40400c00
RDX: 0000000000000000 RSI: ffffffff8dbaa0c3 RDI: ffffffff8be34280
RBP: ffffffff8172d195 R08: 0000000000000000 R09: ffffffff8172d195
R10: ffffc9000328f7b8 R11: ffffffff81ac4d00 R12: 0000000000000002
R13: ffffffff8e13a120 R14: 0000000000000000 R15: 0000000000000246
 unwind_next_frame+0xc2/0x2390
 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
 kfree+0x18e/0x440
 tomoyo_realpath_from_path+0x598/0x5d0
 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: 0033:0x7f3ab318e82b
RSP: 002b:00007ffeda80bee0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000004e3b RCX: 00007f3ab318e82b
RDX: 00007ffeda80bf58 RSI: 0000000040086602 RDI: 0000000000000007
RBP: 00007ffeda80bff0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffeda80d0e0
R13: 00007f3ab3211c2d R14: 00005555818834a8 R15: 0000000000000007
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g36057 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=13552
rcu: rcu_preempt kthread starved for 10502 jiffies! g36057 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:26920 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>
