INFO: rcu_preempt self-detected stall on CPU
	1-...: (1 GPs behind) idle=ee2/140000000000002/0 softirq=13531/13532 fqs=7 
	 (t=10500 jiffies g=2062 c=2061 q=634)
rcu_preempt kthread starved for 10311 jiffies! g2062 c2061 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=0
rcu_preempt     R  running task    29920     8      2 0x80000000
Call Trace:
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_timeout+0x43c/0xe40 kernel/time/timer.c:1746
 rcu_gp_kthread+0xb8e/0x1ce0 kernel/rcu/tree.c:2255
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
NMI backtrace for cpu 1
CPU: 1 PID: 8132 Comm: syz-executor.0 Not tainted 4.14.174-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:17 [inline]
 dump_stack+0x13e/0x194 lib/dump_stack.c:58
 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x139/0x17e lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:158 [inline]
 rcu_dump_cpu_stacks+0x16d/0x1b8 kernel/rcu/tree.c:1396
 print_cpu_stall kernel/rcu/tree.c:1542 [inline]
 check_cpu_stall kernel/rcu/tree.c:1610 [inline]
 __rcu_pending kernel/rcu/tree.c:3390 [inline]
 rcu_pending kernel/rcu/tree.c:3452 [inline]
 rcu_check_callbacks.cold+0x490/0xdaa kernel/rcu/tree.c:2792
 update_process_times+0x29/0x60 kernel/time/timer.c:1590
 tick_sched_handle+0x7d/0x150 kernel/time/tick-sched.c:165
 tick_sched_timer+0x3e/0x120 kernel/time/tick-sched.c:1223
 __run_hrtimer kernel/time/hrtimer.c:1223 [inline]
 __hrtimer_run_queues+0x25c/0xbb0 kernel/time/hrtimer.c:1287
 hrtimer_interrupt+0x1e6/0x5e0 kernel/time/hrtimer.c:1321
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1075 [inline]
 smp_apic_timer_interrupt+0x117/0x5e0 arch/x86/kernel/apic/apic.c:1100
 apic_timer_interrupt+0x8f/0xa0 arch/x86/entry/entry_64.S:792
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:779 [inline]
RIP: 0010:lock_release+0x41e/0x7f0 kernel/locking/lockdep.c:4016
RSP: 0018:ffff8880aeb07630 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10
RAX: 1ffffffff0fa2cd1 RBX: 1ffff11015d60eca RCX: 1ffff11014f9555e
RDX: dffffc0000000000 RSI: 0000000000000005 RDI: 0000000000000282
RBP: ffff8880a7caa280 R08: 0000000000000001 R09: 0000000000000004
R10: ffff8880a7caaba0 R11: ffff8880a7caa280 R12: ffffffff8163259c
R13: 0000000000000003 R14: ffff8880a7caa280 R15: 0000000000000005
 rcu_lock_release include/linux/rcupdate.h:247 [inline]
 rcu_read_unlock include/linux/rcupdate.h:685 [inline]
 is_bpf_text_address+0xa3/0x120 kernel/bpf/core.c:458
 kernel_text_address+0x6e/0xe0 kernel/extable.c:150
 __kernel_text_address+0x9/0x30 kernel/extable.c:105
 unwind_get_return_address arch/x86/kernel/unwind_orc.c:255 [inline]
 unwind_get_return_address+0x5a/0xa0 arch/x86/kernel/unwind_orc.c:250
 __save_stack_trace+0x7b/0xd0 arch/x86/kernel/stacktrace.c:45
 save_stack+0x32/0xa0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc mm/kasan/kasan.c:551 [inline]
 kasan_kmalloc+0xbf/0xe0 mm/kasan/kasan.c:529
 kmem_cache_alloc+0x127/0x770 mm/slab.c:3552
 dst_alloc+0xe6/0x190 net/core/dst.c:107
 __ip6_dst_alloc+0x2e/0x50 net/ipv6/route.c:357
 ip6_dst_alloc+0x2a/0x1d0 net/ipv6/route.c:370
 icmp6_dst_alloc+0x155/0x580 net/ipv6/route.c:1766
 ndisc_send_skb+0xc0f/0x11e0 net/ipv6/ndisc.c:463
 ndisc_send_rs+0x125/0x630 net/ipv6/ndisc.c:677
 addrconf_rs_timer+0x289/0x5a0 net/ipv6/addrconf.c:3761
 call_timer_fn+0x14a/0x650 kernel/time/timer.c:1279
 expire_timers kernel/time/timer.c:1318 [inline]
 __run_timers kernel/time/timer.c:1636 [inline]
 __run_timers kernel/time/timer.c:1604 [inline]
 run_timer_softirq+0x52a/0x1390 kernel/time/timer.c:1649
 __do_softirq+0x254/0x9bf kernel/softirq.c:288
 invoke_softirq kernel/softirq.c:368 [inline]
 irq_exit+0x15b/0x1a0 kernel/softirq.c:409
 exiting_irq arch/x86/include/asm/apic.h:648 [inline]
 smp_apic_timer_interrupt+0x141/0x5e0 arch/x86/kernel/apic/apic.c:1102
 apic_timer_interrupt+0x8f/0xa0 arch/x86/entry/entry_64.S:792
 </IRQ>
RIP: 0010:strlen+0x46/0x90 lib/string.c:482
RSP: 0018:ffff88804ac17810 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10
RAX: ffff888099f3f443 RBX: dffffc0000000000 RCX: 0000000000000002
RDX: ffff888099f3f443 RSI: ffffffff82c84137 RDI: ffff888099f3f440
RBP: ffff888099f3f440 R08: 0000000000000170 R09: ffffffff8a05c400
R10: ffff8880a7caab50 R11: ffff8880a7caa280 R12: ffff888099f3f440
R13: dffffc0000000000 R14: ffff888092177640 R15: dffffc0000000000
 strlen include/linux/string.h:269 [inline]
 __security_genfs_sid security/selinux/ss/services.c:2610 [inline]
 security_fs_use+0x3c4/0x630 security/selinux/ss/services.c:2685
 selinux_set_mnt_opts+0xf81/0x1310 security/selinux/hooks.c:850
 superblock_doinit+0xfc/0x1f0 security/selinux/hooks.c:1216
 selinux_sb_kern_mount+0x91/0x210 security/selinux/hooks.c:2843
 security_sb_kern_mount+0x76/0xb0 security/security.c:379
 mount_fs+0x149/0x2a0 fs/super.c:1255
 vfs_kern_mount.part.0+0x5b/0x3c0 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 kern_mount_data+0x51/0xb0 fs/namespace.c:3329
 pid_ns_prepare_proc+0x1a/0x80 fs/proc/root.c:222
 alloc_pid+0x9be/0xc40 kernel/pid.c:324
 copy_process.part.0+0x272f/0x6a70 kernel/fork.c:1785
 copy_process kernel/fork.c:1586 [inline]
 _do_fork+0x180/0xc80 kernel/fork.c:2070
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45c849
RSP: 002b:00007fde6020bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007fde6020c6d4 RCX: 000000000045c849
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000030020100
RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000074 R14: 00000000004c3103 R15: 000000000076bf0c
INFO: rcu_sched detected stalls on CPUs/tasks:
	(detected by 0, t=10577 jiffies, g=1470, c=1469, q=6)
All QSes seen, last rcu_sched kthread activity 10577 (4294972879-4294962302), jiffies_till_next_fqs=1, root ->qsmask 0x0
syz-executor.1  R  running task    27728  8136   7422 0x00000008
Call Trace:
 <IRQ>
 sched_show_task kernel/sched/core.c:5168 [inline]
 sched_show_task.cold+0x2e3/0x347 kernel/sched/core.c:5143
 print_other_cpu_stall kernel/rcu/tree.c:1501 [inline]
 check_cpu_stall kernel/rcu/tree.c:1616 [inline]
 __rcu_pending kernel/rcu/tree.c:3390 [inline]
 rcu_pending kernel/rcu/tree.c:3452 [inline]
 rcu_check_callbacks.cold+0xd3f/0xdaa kernel/rcu/tree.c:2792
 update_process_times+0x29/0x60 kernel/time/timer.c:1590
 tick_sched_handle+0x7d/0x150 kernel/time/tick-sched.c:165
 tick_sched_timer+0x3e/0x120 kernel/time/tick-sched.c:1223
 __run_hrtimer kernel/time/hrtimer.c:1223 [inline]
 __hrtimer_run_queues+0x25c/0xbb0 kernel/time/hrtimer.c:1287
 hrtimer_interrupt+0x1e6/0x5e0 kernel/time/hrtimer.c:1321
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1075 [inline]
 smp_apic_timer_interrupt+0x117/0x5e0 arch/x86/kernel/apic/apic.c:1100
 apic_timer_interrupt+0x8f/0xa0 arch/x86/entry/entry_64.S:792
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:779 [inline]
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x91/0xe0 kernel/locking/spinlock.c:192
RSP: 0018:ffff8880aea075b8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10
RAX: 1ffffffff0fa2cd1 RBX: 0000000000000282 RCX: 1ffff110126a1590
RDX: dffffc0000000000 RSI: ffff88809350acd8 RDI: 0000000000000282
RBP: ffffffff8a6b4088 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000053200
R13: ffff8880900057e0 R14: 0000000000000000 R15: ffffffff8a6b4088
 __debug_object_init+0x167/0x830 lib/debugobjects.c:380
 debug_object_init lib/debugobjects.c:393 [inline]
 debug_object_activate+0x274/0x450 lib/debugobjects.c:474
 debug_rcu_head_queue kernel/rcu/rcu.h:152 [inline]
 __call_rcu.constprop.0+0x31/0x7e0 kernel/rcu/tree.c:3050
 dst_release+0x56/0x80 net/core/dst.c:188
 refdst_drop include/net/dst.h:286 [inline]
 skb_dst_drop include/net/dst.h:298 [inline]
 __dev_queue_xmit+0x17df/0x25c0 net/core/dev.c:3484
 neigh_hh_output include/net/neighbour.h:490 [inline]
 neigh_output include/net/neighbour.h:498 [inline]
 ip6_finish_output2+0x1085/0x2150 net/ipv6/ip6_output.c:120
 ip6_finish_output+0x4d9/0xaf0 net/ipv6/ip6_output.c:154
 NF_HOOK_COND include/linux/netfilter.h:239 [inline]
 ip6_output+0x1c9/0x650 net/ipv6/ip6_output.c:171
 dst_output include/net/dst.h:462 [inline]
 NF_HOOK include/linux/netfilter.h:250 [inline]
 ndisc_send_skb+0xb56/0x11e0 net/ipv6/ndisc.c:483
 ndisc_send_rs+0x125/0x630 net/ipv6/ndisc.c:677
 addrconf_rs_timer+0x289/0x5a0 net/ipv6/addrconf.c:3761
 call_timer_fn+0x14a/0x650 kernel/time/timer.c:1279
 expire_timers kernel/time/timer.c:1318 [inline]
 __run_timers kernel/time/timer.c:1636 [inline]
 __run_timers kernel/time/timer.c:1604 [inline]
 run_timer_softirq+0x52a/0x1390 kernel/time/timer.c:1649
 __do_softirq+0x254/0x9bf kernel/softirq.c:288
 invoke_softirq kernel/softirq.c:368 [inline]
 irq_exit+0x15b/0x1a0 kernel/softirq.c:409
 exiting_irq arch/x86/include/asm/apic.h:648 [inline]
 smp_apic_timer_interrupt+0x141/0x5e0 arch/x86/kernel/apic/apic.c:1102
 apic_timer_interrupt+0x8f/0xa0 arch/x86/entry/entry_64.S:792
 </IRQ>
RIP: 0010:ext4_itable_unused_count+0x49/0x100 fs/ext4/super.c:278
RSP: 0018:ffff88804b3c7b28 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10
RAX: 0000000000000005 RBX: ffff8880bfff4040 RCX: ffffc90009e4c000
RDX: 0000000000000000 RSI: ffffffff81c9fc9f RDI: ffff888215446a00
RBP: ffff888215446380 R08: 0000000000000001 R09: 00000000000483d4
R10: ffff88809350ac38 R11: ffff88809350a340 R12: 0000000000001f47
R13: 0000000000000000 R14: ffff8880bfff4040 R15: ffff888215446380
 __ext4_new_inode+0x1a07/0x4e90 fs/ext4/ialloc.c:1044
 ext4_mkdir+0x2e4/0xb60 fs/ext4/namei.c:2665
 vfs_mkdir+0x3af/0x620 fs/namei.c:3849
 SYSC_mkdirat fs/namei.c:3872 [inline]
 SyS_mkdirat fs/namei.c:3856 [inline]
 SYSC_mkdir fs/namei.c:3883 [inline]
 SyS_mkdir+0x1bc/0x210 fs/namei.c:3881
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45bc67
RSP: 002b:00007f6052bc0a68 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007f6052bc16d4 RCX: 000000000045bc67
RDX: 0000000000000004 RSI: 00000000000001ff RDI: 0000000020000180
RBP: 000000000076bf00 R08: 0000000000000000 R09: 000000000000000a
R10: 0000000000000075 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000bec R14: 00000000004ce0fd R15: 000000000076bf0c
rcu_sched kthread starved for 10627 jiffies! g1470 c1469 f0x2 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=1
rcu_sched       R  running task    29984     9      2 0x80000000
Call Trace:
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_timeout+0x43c/0xe40 kernel/time/timer.c:1746
 rcu_gp_kthread+0xb8e/0x1ce0 kernel/rcu/tree.c:2255
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404