rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (10500 ticks this GP) idle=366/1/0x4000000000000004 softirq=363585/363585 fqs=5237 
	(t=10501 jiffies g=347217 q=300944)
NMI backtrace for cpu 1
CPU: 1 PID: 30533 Comm: syz-executor.0 Not tainted 5.6.0-rc7-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:77 [inline]
 dump_stack+0x1e9/0x30e lib/dump_stack.c:118
 nmi_cpu_backtrace+0x9f/0x180 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x16a/0x280 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x169/0x250 kernel/rcu/tree_stall.h:254
 print_cpu_stall kernel/rcu/tree_stall.h:475 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:549 [inline]
 rcu_pending kernel/rcu/tree.c:3030 [inline]
 rcu_sched_clock_irq+0x171f/0x1970 kernel/rcu/tree.c:2276
 update_process_times+0x12c/0x180 kernel/time/timer.c:1726
 tick_sched_handle kernel/time/tick-sched.c:171 [inline]
 tick_sched_timer+0x254/0x410 kernel/time/tick-sched.c:1314
 __run_hrtimer kernel/time/hrtimer.c:1517 [inline]
 __hrtimer_run_queues+0x3cf/0x7d0 kernel/time/hrtimer.c:1579
 hrtimer_interrupt+0x373/0xd60 kernel/time/hrtimer.c:1641
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1119 [inline]
 smp_apic_timer_interrupt+0x109/0x280 arch/x86/kernel/apic/apic.c:1144
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
RIP: 0010:tcp_twsk_destructor+0x5a/0x70 net/ipv4/tcp_minisocks.c:350
Code: 00 74 08 48 89 df e8 f5 4c e3 fa 48 8b 1b 48 85 db 74 17 e8 e8 f3 a6 fa 48 83 c3 78 be 78 00 00 00 48 89 df 5b e9 06 72 94 fa <e8> d1 f3 a6 fa 5b c3 0f 1f 44 00 00 66 2e 0f 1f 84 00 00 00 00 00
RSP: 0018:ffffc90000da8d10 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 1ffff11012d1ccc9 RBX: 0000000000000000 RCX: dffffc0000000000
RDX: 0000000000000101 RSI: 0000000000000001 RDI: ffff8880968e6540
RBP: 1ffff11012d1ccad R08: ffffffff86c2fb12 R09: ffffed1012d1ccb9
R10: ffffed1012d1ccb9 R11: 0000000000000000 R12: ffff8880968e6540
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880968e6568
 twsk_destructor include/net/timewait_sock.h:33 [inline]
 inet_twsk_free net/ipv4/inet_timewait_sock.c:69 [inline]
 inet_twsk_put+0xe5/0x1a0 net/ipv4/inet_timewait_sock.c:80
 call_timer_fn+0x91/0x160 kernel/time/timer.c:1404
 expire_timers kernel/time/timer.c:1449 [inline]
 __run_timers+0x776/0x970 kernel/time/timer.c:1773
 run_timer_softirq+0x46/0x80 kernel/time/timer.c:1786
 __do_softirq+0x268/0x7c5 kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x223/0x230 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:546 [inline]
 smp_apic_timer_interrupt+0x113/0x280 arch/x86/kernel/apic/apic.c:1146
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 </IRQ>
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:759 [inline]
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa5/0xd0 kernel/locking/spinlock.c:191
Code: b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 0c 48 c7 c7 18 d4 0a 89 e8 aa 0f b6 f9 48 83 3d 9a f4 0f 01 00 74 2c 4c 89 f7 57 9d <0f> 1f 44 00 00 bf 01 00 00 00 e8 3c a2 56 f9 65 8b 05 31 3e 07 78
RSP: 0018:ffffc90001ac79b0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff1215a83 RBX: ffffffff8b4fbe88 RCX: dffffc0000000000
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: 0000000000000282
RBP: 1ffff1101135a8e3 R08: ffffffff817a2210 R09: fffffbfff169f7d2
R10: fffffbfff169f7d2 R11: 0000000000000000 R12: ffffc90019331000
R13: 000000000000000c R14: 0000000000000282 R15: 00000000000000ff
 __debug_check_no_obj_freed lib/debugobjects.c:977 [inline]
 debug_check_no_obj_freed+0x592/0x640 lib/debugobjects.c:998
 __vunmap+0x286/0xa20 mm/vmalloc.c:2302
 kcov_put kernel/kcov.c:396 [inline]
 kcov_close+0x27/0x50 kernel/kcov.c:495
 __fput+0x2d8/0x730 fs/file_table.c:280
 task_work_run+0x176/0x1b0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x5ef/0x1f80 kernel/exit.c:801
 do_group_exit+0x15e/0x2c0 kernel/exit.c:899
 get_signal+0x13cf/0x1d60 kernel/signal.c:2739
 do_signal+0x33/0x610 arch/x86/kernel/signal.c:813
 exit_to_usermode_loop arch/x86/entry/common.c:160 [inline]
 prepare_exit_to_usermode+0x32a/0x600 arch/x86/entry/common.c:195
 ret_from_intr+0x26/0x36
RIP: 0033:0x45c849
Code: 24 78 48 39 c2 74 12 c6 84 24 90 00 00 00 00 48 8b 6c 24 58 48 83 c4 60 c3 48 8b 44 24 70 48 89 04 24 48 89 4c 24 08 48 89 54 <24> 10 e8 d0 5c fa ff 80 7c 24 18 00 74 cf 48 8b 44 24 38 48 8b 48
RSP: 002b:00007f85371bccf8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: 000000000076c048 RCX: 000000000045c849
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000076c048
RBP: 000000000076c040 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000076c04c
R13: 00007ffc3ee934df R14: 00007f85371bd9c0 R15: 000000000076c04c