rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (10499 ticks this GP) idle=522/1/0x4000000000000002 softirq=13698/13699 fqs=2720 
	(t=10500 jiffies g=6765 q=252)
rcu: rcu_preempt kthread starved for 5046 jiffies! g6765 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: RCU grace-period kthread stack dump:
rcu_preempt     R  running task    28984    10      2 0x80004000
Call Trace:
 context_switch kernel/sched/core.c:3385 [inline]
 __schedule+0x9a0/0xcc0 kernel/sched/core.c:4081
 schedule+0x181/0x210 kernel/sched/core.c:4155
 schedule_timeout+0x14f/0x240 kernel/time/timer.c:1895
 rcu_gp_fqs_loop kernel/rcu/tree.c:1661 [inline]
 rcu_gp_kthread+0xed8/0x1770 kernel/rcu/tree.c:1821
 kthread+0x332/0x350 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
NMI backtrace for cpu 0
CPU: 0 PID: 8487 Comm: syz-executor.1 Not tainted 5.5.0-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:77 [inline]
 dump_stack+0x1fb/0x318 lib/dump_stack.c:118
 nmi_cpu_backtrace+0xaf/0x1a0 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x174/0x290 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x10/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x15a/0x220 kernel/rcu/tree_stall.h:254
 print_cpu_stall kernel/rcu/tree_stall.h:455 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:529 [inline]
 rcu_pending kernel/rcu/tree.c:2827 [inline]
 rcu_sched_clock_irq+0xe25/0x1ad0 kernel/rcu/tree.c:2271
 update_process_times+0x12d/0x180 kernel/time/timer.c:1726
 tick_sched_handle kernel/time/tick-sched.c:167 [inline]
 tick_sched_timer+0x263/0x420 kernel/time/tick-sched.c:1310
 __run_hrtimer kernel/time/hrtimer.c:1517 [inline]
 __hrtimer_run_queues+0x403/0x840 kernel/time/hrtimer.c:1579
 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1641
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline]
 smp_apic_timer_interrupt+0x109/0x280 arch/x86/kernel/apic/apic.c:1135
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 </IRQ>
RIP: 0010:__memcg_kmem_uncharge+0x44/0x1a0 mm/memcontrol.c:2912
Code: fc ff df 4c 8d 77 38 4d 89 f5 49 c1 ed 03 41 80 7c 05 00 00 74 08 4c 89 f7 e8 48 07 fb ff 4d 8b 3e b8 01 00 00 00 89 d9 d3 e0 <4d> 85 ff 0f 84 de 00 00 00 4c 39 3d a4 be ac 07 0f 84 2c 01 00 00
RSP: 0018:ffffc90001fa78a8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffea0002a13f00
RBP: ffffc90001fa78d8 R08: dffffc0000000000 R09: fffffbfff124248a
R10: fffffbfff124248a R11: 0000000000000000 R12: ffffea0002a13f00
R13: 1ffffd40005427e7 R14: ffffea0002a13f38 R15: 0000000000000000
 memcg_kmem_uncharge include/linux/memcontrol.h:1402 [inline]
 free_thread_stack+0x12e/0x590 kernel/fork.c:284
 release_task_stack kernel/fork.c:440 [inline]
 put_task_stack+0xa3/0x130 kernel/fork.c:451
 finish_task_switch+0x3f1/0x550 kernel/sched/core.c:3256
 context_switch kernel/sched/core.c:3388 [inline]
 __schedule+0x9a8/0xcc0 kernel/sched/core.c:4081
 preempt_schedule_irq+0xc1/0x140 kernel/sched/core.c:4338
 retint_kernel+0x1b/0x2b
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:752 [inline]
RIP: 0010:kfree+0x1a3/0x200 mm/slab.c:3758
Code: 48 83 3d 07 04 78 07 00 74 68 4c 89 f7 57 9d 0f 1f 44 00 00 eb 19 e8 3c d3 c9 ff 48 83 3d ec 03 78 07 00 74 51 4c 89 f7 57 9d <0f> 1f 44 00 00 5b 41 5c 41 5e 41 5f 5d c3 48 ff c9 48 89 c8 e9 c8
RSP: 0018:ffffc90001fa7b38 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff02
RAX: ffff888097f50914 RBX: ffff8880aa4001c0 RCX: ffffffff815c1e17
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000286
RBP: ffffc90001fa7b58 R08: ffff888097f508d8 R09: fffffbfff140cf2e
R10: fffffbfff140cf2e R11: 0000000000000000 R12: ffff88809faa9d00
R13: dffffc0000000000 R14: 0000000000000286 R15: ffffffff835d65ab
 smack_sk_free_security+0x3b/0x40 security/smack/smack_lsm.c:2292
 security_sk_free+0x52/0x90 security/security.c:2074
 sk_prot_free net/core/sock.c:1636 [inline]
 __sk_destruct+0x5ff/0x750 net/core/sock.c:1724
 sk_destruct net/core/sock.c:1739 [inline]
 __sk_free+0x35d/0x430 net/core/sock.c:1750
 sk_free+0x51/0x90 net/core/sock.c:1761
 sock_put include/net/sock.h:1734 [inline]
 tcp_close+0xec9/0x1200 net/ipv4/tcp.c:2510
 inet_release+0x165/0x1c0 net/ipv4/af_inet.c:427
 inet6_release+0x57/0x70 net/ipv6/af_inet6.c:470
 __sock_release net/socket.c:592 [inline]
 sock_close+0xe1/0x260 net/socket.c:1270
 __fput+0x2e4/0x740 fs/file_table.c:280
 ____fput+0x15/0x20 fs/file_table.c:313
 task_work_run+0x17e/0x1b0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop arch/x86/entry/common.c:164 [inline]
 prepare_exit_to_usermode+0x483/0x5b0 arch/x86/entry/common.c:195
 syscall_return_slowpath+0x113/0x4a0 arch/x86/entry/common.c:278
 do_syscall_64+0x11f/0x1c0 arch/x86/entry/common.c:304
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x414ac0
Code: 01 f0 ff ff 0f 83 30 1b 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 83 3d ad 39 66 00 00 75 14 b8 03 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 04 1b 00 00 c3 48 83 ec 08 e8 0a fc ff ff
RSP: 002b:00007fff30780f68 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 00007fff30780f90 RCX: 0000000000414ac0
RDX: 0000000000000010 RSI: 00007fff30781410 RDI: 0000000000000003
RBP: 0000000000719cc0 R08: 0000000000006000 R09: 0000000000004000
R10: 00007fff30781090 R11: 0000000000000246 R12: 0000000000000003
R13: 0000000000000000 R14: 0000000000000029 R15: 0000000000719cc0