rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (10500 ticks this GP) idle=93e/1/0x4000000000000000 softirq=191404/191404 fqs=5230 
	(t=10502 jiffies g=341465 q=1048)
NMI backtrace for cpu 1
CPU: 1 PID: 19492 Comm: syz-executor.5 Not tainted 5.8.0-rc3-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+0x1f0/0x31e 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+0x199/0x2a0 kernel/rcu/tree_stall.h:320
 print_cpu_stall kernel/rcu/tree_stall.h:553 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:627 [inline]
 rcu_pending kernel/rcu/tree.c:3489 [inline]
 rcu_sched_clock_irq+0x1928/0x1eb0 kernel/rcu/tree.c:2504
 update_process_times+0x12c/0x180 kernel/time/timer.c:1726
 tick_sched_handle kernel/time/tick-sched.c:176 [inline]
 tick_sched_timer+0x254/0x410 kernel/time/tick-sched.c:1320
 __run_hrtimer kernel/time/hrtimer.c:1520 [inline]
 __hrtimer_run_queues+0x42d/0x930 kernel/time/hrtimer.c:1584
 hrtimer_interrupt+0x373/0xd60 kernel/time/hrtimer.c:1646
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline]
 __sysvec_apic_timer_interrupt+0xf0/0x260 arch/x86/kernel/apic/apic.c:1097
 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:711
 </IRQ>
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline]
 sysvec_apic_timer_interrupt+0xb9/0x130 arch/x86/kernel/apic/apic.c:1091
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:596
RIP: 0010:perf_output_read_group kernel/events/core.c:6695 [inline]
RIP: 0010:perf_output_read+0xe35/0x1210 kernel/events/core.c:6732
Code: 11 c3 23 00 48 89 d8 48 c1 e8 03 4d 89 ef 42 80 3c 28 00 74 08 48 89 df e8 48 f3 23 00 4c 03 23 48 8b 44 24 68 42 80 3c 38 00 <74> 0a 48 8d 7c 24 70 e8 af f3 23 00 4c 89 64 24 70 48 83 7c 24 28
RSP: 0018:ffffc90008f174b0 EFLAGS: 00000246
RAX: 1ffff920011e2ea4 RBX: ffff8880421c40b8 RCX: ffffffff818f86df
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff8880421c40b8
RBP: ffffc90008f17590 R08: dffffc0000000000 R09: ffffed1008438818
R10: ffffed1008438818 R11: 0000000000000000 R12: 0000000021f646d5
R13: dffffc0000000000 R14: ffff8880421c4000 R15: dffffc0000000000
 perf_output_sample+0x2ae/0x20a0 kernel/events/core.c:6779
 __perf_event_output kernel/events/core.c:7160 [inline]
 perf_event_output_forward+0x10b/0x1c0 kernel/events/core.c:7174
 __perf_event_overflow+0x1b9/0x340 kernel/events/core.c:8746
 do_perf_sw_event kernel/events/core.c:8963 [inline]
 ___perf_sw_event+0x41f/0x550 kernel/events/core.c:8994
 __perf_sw_event+0x13e/0x230 kernel/events/core.c:9006
 handle_page_fault arch/x86/mm/fault.c:1365 [inline]
 exc_page_fault+0x124/0x1f0 arch/x86/mm/fault.c:1418
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:565
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:ffffc90008f17ab0 EFLAGS: 00010206
RAX: ffffffff839b3101 RBX: 0000000020eb4fcb RCX: 0000000000002fcb
RDX: 0000000000008000 RSI: 0000000020eb2000 RDI: ffff888041fdd035
RBP: ffff888041fd8000 R08: dffffc0000000000 R09: ffffed10083fc000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000008000
R13: 0000000020eacfcb R14: ffffc90008f17dc8 R15: 0000000000008000
 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 lib/iov_iter.c:152 [inline]
 _copy_from_iter_full+0x2ba/0xaa0 lib/iov_iter.c:790
 copy_from_iter_full include/linux/uio.h:156 [inline]
 skb_do_copy_data_nocache+0xf6/0x2f0 include/net/sock.h:2037
 skb_copy_to_page_nocache include/net/sock.h:2063 [inline]
 tcp_sendmsg_locked+0x1863/0x3ed0 net/ipv4/tcp.c:1343
 tcp_sendmsg+0x2c/0x40 net/ipv4/tcp.c:1441
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 __sys_sendto+0x429/0x5c0 net/socket.c:1995
 __do_sys_sendto net/socket.c:2007 [inline]
 __se_sys_sendto net/socket.c:2003 [inline]
 __x64_sys_sendto+0xda/0xf0 net/socket.c:2003
 do_syscall_64+0x73/0xe0 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45cb29
Code: Bad RIP value.
RSP: 002b:00007f2c0f457c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000502960 RCX: 000000000045cb29
RDX: ffffffffffffffef RSI: 0000000020d7cfcb RDI: 0000000000000005
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000053
R10: 0000000041020000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000a4c R14: 00000000004cd338 R15: 00007f2c0f4586d4