rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (1 GPs behind) idle=242/1/0x4000000000000000 softirq=43154/43155 fqs=5220 
	(t=10500 jiffies g=79697 q=1035)
NMI backtrace for cpu 0
CPU: 0 PID: 21346 Comm: syz-executor.2 Not tainted 5.9.0-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+0x198/0x1fd lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x1e3/0x21e kernel/rcu/tree_stall.h:318
 print_cpu_stall kernel/rcu/tree_stall.h:551 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:625 [inline]
 rcu_pending kernel/rcu/tree.c:3639 [inline]
 rcu_sched_clock_irq.cold+0x4db/0xdfd kernel/rcu/tree.c:2521
 update_process_times+0x25/0xa0 kernel/time/timer.c:1710
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:176
 tick_sched_timer+0x1d1/0x2a0 kernel/time/tick-sched.c:1328
 __run_hrtimer kernel/time/hrtimer.c:1524 [inline]
 __hrtimer_run_queues+0x1d5/0xfc0 kernel/time/hrtimer.c:1588
 hrtimer_interrupt+0x334/0x940 kernel/time/hrtimer.c:1650
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline]
 __sysvec_apic_timer_interrupt+0x147/0x5f0 arch/x86/kernel/apic/apic.c:1097
 asm_call_irq_on_stack+0xf/0x20
 </IRQ>
 __run_sysvec_on_irqstack arch/x86/include/asm/irq_stack.h:37 [inline]
 run_sysvec_on_irqstack_cond arch/x86/include/asm/irq_stack.h:89 [inline]
 sysvec_apic_timer_interrupt+0xb2/0xf0 arch/x86/kernel/apic/apic.c:1091
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581
RIP: 0010:primary_event_id kernel/events/core.c:1431 [inline]
RIP: 0010:perf_output_read_group kernel/events/core.c:6714 [inline]
RIP: 0010:perf_output_read+0xcb3/0x1310 kernel/events/core.c:6749
Code: 38 01 00 00 e8 6e 76 e5 ff 4d 85 f6 0f 84 86 00 00 00 e8 e0 79 e5 ff 49 8d bf e0 04 00 00 48 89 f8 48 c1 e8 03 42 80 3c 28 00 <0f> 85 da 04 00 00 48 8b 44 24 10 48 8d b8 e0 02 00 00 4c 8b a0 e0
RSP: 0018:ffffc9000a38ef98 EFLAGS: 00000246
RAX: 1ffff1101430609c RBX: ffffc9000a38f2e0 RCX: ffffc9000d536000
RDX: 0000000000040000 RSI: ffffffff8190c530 RDI: ffff8880a18304e0
RBP: 0000000000000000 R08: 0000000000000000 R09: ffff8880a18300bf
R10: 0000000000000000 R11: 0000000000000001 R12: ffff8880a18300b8
R13: dffffc0000000000 R14: 0000000000000004 R15: ffff8880a1830000
 perf_output_sample+0x102c/0x1c60 kernel/events/core.c:6796
 __perf_event_output kernel/events/core.c:7177 [inline]
 perf_event_output_forward+0x12f/0x270 kernel/events/core.c:7191
 __perf_event_overflow+0x13c/0x370 kernel/events/core.c:8846
 perf_swevent_overflow kernel/events/core.c:8922 [inline]
 perf_swevent_event+0x347/0x550 kernel/events/core.c:8950
 do_perf_sw_event kernel/events/core.c:9063 [inline]
 ___perf_sw_event+0x31a/0x570 kernel/events/core.c:9094
 __perf_sw_event+0x54/0x130 kernel/events/core.c:9106
 perf_sw_event include/linux/perf_event.h:1159 [inline]
 mm_account_fault mm/memory.c:4563 [inline]
 handle_mm_fault+0x1219/0x4590 mm/memory.c:4614
 do_user_addr_fault+0x598/0xbf0 arch/x86/mm/fault.c:1372
 handle_page_fault arch/x86/mm/fault.c:1429 [inline]
 exc_page_fault+0xa8/0x190 arch/x86/mm/fault.c:1482
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:538
RIP: 0010:copy_user_enhanced_fast_string+0xe/0x30 arch/x86/lib/copy_user_64.S:205
Code: 89 d1 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 31 c0 0f 1f 00 c3 0f 1f 80 00 00 00 00 0f 1f 00 83 fa 40 0f 82 70 ff ff ff 89 d1 <f3> a4 31 c0 0f 1f 00 c3 66 2e 0f 1f 84 00 00 00 00 00 89 d1 f3 a4
RSP: 0018:ffffc9000a38f9c8 EFLAGS: 00010206
RAX: 0000000000000001 RBX: 0000000000008000 RCX: 0000000000007fcb
RDX: 0000000000008000 RSI: 0000000020eed000 RDI: ffff888040618035
RBP: ffff888040618000 R08: 0000000000000001 R09: ffff88804061ffff
R10: ffffed10080c3fff R11: 0000000000000000 R12: 0000000020eecfcb
R13: 0000000020ef4fcb R14: 00007ffffffff000 R15: 0000000000000000
 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline]
 raw_copy_from_user arch/x86/include/asm/uaccess_64.h:68 [inline]
 copyin+0x107/0x140 lib/iov_iter.c:153
 _copy_from_iter_full+0x206/0x8a0 lib/iov_iter.c:791
 copy_from_iter_full include/linux/uio.h:155 [inline]
 skb_do_copy_data_nocache+0x145/0x2c0 include/net/sock.h:2038
 skb_copy_to_page_nocache include/net/sock.h:2064 [inline]
 tcp_sendmsg_locked+0x112c/0x2d20 net/ipv4/tcp.c:1344
 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1442
 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:817
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:671
 __sys_sendto+0x21c/0x320 net/socket.c:1992
 __do_sys_sendto net/socket.c:2004 [inline]
 __se_sys_sendto net/socket.c:2000 [inline]
 __x64_sys_sendto+0xdd/0x1b0 net/socket.c:2000
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45de59
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:00007f85ef782c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 000000000002e880 RCX: 000000000045de59
RDX: ffffffffffffffef RSI: 0000000020d7cfcb RDI: 0000000000000004
RBP: 000000000118bf78 R08: 0000000000000000 R09: 0000000000000053
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c
R13: 00007ffeb1c0c24f R14: 00007f85ef7839c0 R15: 000000000118bf2c