syzbot

rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (1 GPs behind) idle=b62/1/0x4000000000000000 softirq=195733/195734 fqs=5200 
	(t=10502 jiffies g=364825 q=5849)
NMI backtrace for cpu 0
CPU: 0 PID: 31820 Comm: syz-executor.4 Not tainted 5.11.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x107/0x163 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x1f4/0x230 kernel/rcu/tree_stall.h:337
 print_cpu_stall kernel/rcu/tree_stall.h:569 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:643 [inline]
 rcu_pending kernel/rcu/tree.c:3751 [inline]
 rcu_sched_clock_irq.cold+0x48e/0xedf kernel/rcu/tree.c:2580
 update_process_times+0x16d/0x200 kernel/time/timer.c:1782
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226
 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1369
 __run_hrtimer kernel/time/hrtimer.c:1519 [inline]
 __hrtimer_run_queues+0x1c0/0xe40 kernel/time/hrtimer.c:1583
 hrtimer_interrupt+0x334/0x940 kernel/time/hrtimer.c:1645
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x540 arch/x86/kernel/apic/apic.c:1102
 run_sysvec_on_irqstack_cond arch/x86/include/asm/irq_stack.h:91 [inline]
 sysvec_apic_timer_interrupt+0x48/0x100 arch/x86/kernel/apic/apic.c:1096
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:628
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x25/0x50 kernel/locking/spinlock.c:191
Code: f8 5d c3 66 90 55 48 89 fd 48 83 c7 18 53 48 89 f3 48 8b 74 24 10 e8 6a 95 5c f8 48 89 ef e8 12 4a 5d f8 f6 c7 02 75 1a 53 9d <bf> 01 00 00 00 e8 31 51 51 f8 65 8b 05 1a c9 05 77 85 c0 74 0a 5b
RSP: 0018:ffffc90000007c10 EFLAGS: 00000246
RAX: 0000000001026d8e RBX: 0000000000000246 RCX: ffffffff81584047
RDX: 0000000000000000 RSI: 0000000000000101 RDI: 0000000000000000
RBP: ffff8880b9e24880 R08: 0000000000000001 R09: ffffffff8ed31877
R10: fffffbfff1da630e R11: 0000000000000000 R12: 000000010003113e
R13: ffff8880b9e24880 R14: 0000000000000000 R15: 00000000ffffffff
 __mod_timer+0x837/0xe30 kernel/time/timer.c:1063
 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1417
 expire_timers kernel/time/timer.c:1462 [inline]
 __run_timers.part.0+0x67c/0xa50 kernel/time/timer.c:1731
 __run_timers kernel/time/timer.c:1712 [inline]
 run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1744
 __do_softirq+0x2bc/0xa29 kernel/softirq.c:343
 asm_call_irq_on_stack+0xf/0x20
 </IRQ>
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline]
 do_softirq_own_stack+0xaa/0xd0 arch/x86/kernel/irq_64.c:77
 invoke_softirq kernel/softirq.c:226 [inline]
 __irq_exit_rcu kernel/softirq.c:420 [inline]
 irq_exit_rcu+0x134/0x200 kernel/softirq.c:432
 sysvec_apic_timer_interrupt+0x4d/0x100 arch/x86/kernel/apic/apic.c:1096
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:628
RIP: 0010:kmalloc_slab+0x5d/0xc0 mm/slab_common.c:649
Code: 00 20 00 00 77 40 83 ef 01 bd ff ff ff ff 0f bd ef 83 c5 01 89 d8 83 e0 01 83 c0 01 83 e3 11 0f 45 d8 89 db 48 83 fb 02 77 33 <83> fd 0d 41 89 ec 77 1a 48 6b db 0e 4c 01 e3 48 8b 04 dd 20 ae e6
RSP: 0018:ffffc90018a8f4c8 EFLAGS: 00000293
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffc90011682000
RDX: 0000000000040000 RSI: 0000000000000d40 RDI: 0000000000000004
RBP: 0000000000000006 R08: 0000000000000017 R09: 0000000000000052
R10: ffffffff83881d51 R11: 000000000000005d R12: 0000000000000d40
R13: 0000000000000022 R14: 0000000000000017 R15: 0000000000000052
 __kmalloc+0x36/0x3e0 mm/slub.c:3962
 kmalloc include/linux/slab.h:557 [inline]
 kzalloc include/linux/slab.h:682 [inline]
 tomoyo_encode2.part.0+0xe9/0x3a0 security/tomoyo/realpath.c:45
 tomoyo_encode2 security/tomoyo/realpath.c:31 [inline]
 tomoyo_encode+0x28/0x50 security/tomoyo/realpath.c:80
 tomoyo_realpath_from_path+0x186/0x620 security/tomoyo/realpath.c:288
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_number_perm+0x1d5/0x590 security/tomoyo/file.c:723
 tomoyo_path_mknod+0x10d/0x190 security/tomoyo/tomoyo.c:240
 security_path_mknod+0xf9/0x170 security/security.c:1079
 may_o_create fs/namei.c:2930 [inline]
 lookup_open.isra.0+0x431/0x1350 fs/namei.c:3071
 open_last_lookups fs/namei.c:3180 [inline]
 path_openat+0x96d/0x2730 fs/namei.c:3368
 do_filp_open+0x17e/0x3c0 fs/namei.c:3398
 do_sys_openat2+0x16d/0x420 fs/open.c:1172
 do_sys_open fs/open.c:1188 [inline]
 __do_sys_open fs/open.c:1196 [inline]
 __se_sys_open fs/open.c:1192 [inline]
 __x64_sys_open+0x119/0x1c0 fs/open.c:1192
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45e219
Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fce9666bc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045e219
RDX: 0000000000000000 RSI: 0000000000145042 RDI: 0000000020000080
RBP: 000000000119bfc0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119bf8c
R13: 00000000016afb5f R14: 00007fce9666c9c0 R15: 000000000119bf8c