rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (10499 ticks this GP) idle=4be/1/0x4000000000000000 softirq=124650/124650 fqs=5196 
	(t=10500 jiffies g=241329 q=3125)
NMI backtrace for cpu 1
CPU: 1 PID: 31791 Comm: syz-executor.0 Not tainted 5.8.0-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+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: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:3637 [inline]
 rcu_sched_clock_irq+0x1920/0x1eb0 kernel/rcu/tree.c:2519
 update_process_times+0x130/0x1b0 kernel/time/timer.c:1710
 tick_sched_handle kernel/time/tick-sched.c:176 [inline]
 tick_sched_timer+0x25e/0x410 kernel/time/tick-sched.c:1328
 __run_hrtimer kernel/time/hrtimer.c:1524 [inline]
 __hrtimer_run_queues+0x42d/0x930 kernel/time/hrtimer.c:1588
 hrtimer_interrupt+0x373/0xd60 kernel/time/hrtimer.c:1650
 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:706
 </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+0x94/0xf0 arch/x86/kernel/apic/apic.c:1091
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581
RIP: 0010:memcpy_erms+0x8/0x10 arch/x86/lib/memcpy_64.S:59
Code: cc cc eb 1e 0f 1f 00 48 89 f8 48 89 d1 48 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 c3 66 0f 1f 44 00 00 48 89 f8 48 89 d1 f3 a4 <c3> 0f 1f 80 00 00 00 00 48 89 f8 48 83 fa 20 72 7e 40 38 fe 7c 35
RSP: 0018:ffffc9000a9072a8 EFLAGS: 00000202
RAX: ffff888020d9ff98 RBX: 0000000000000010 RCX: 0000000000000000
RDX: 0000000000000010 RSI: ffffc9000a907330 RDI: ffff888020d9ffa8
RBP: ffffc9000a907390 R08: dffffc0000000000 R09: ffffed10041b3ff5
R10: ffffed10041b3ff5 R11: 0000000000000000 R12: 0000000000000010
R13: ffffc9000a9074b0 R14: ffffc9000a907320 R15: dffffc0000000000
 memcpy_common kernel/events/internal.h:174 [inline]
 __output_copy kernel/events/internal.h:178 [inline]
 perf_output_read_group kernel/events/core.c:6715 [inline]
 perf_output_read+0xf46/0x1210 kernel/events/core.c:6748
 perf_output_sample+0x2ae/0x20a0 kernel/events/core.c:6795
 __perf_event_output kernel/events/core.c:7176 [inline]
 perf_event_output_forward+0x10b/0x1c0 kernel/events/core.c:7190
 __perf_event_overflow+0x1b9/0x340 kernel/events/core.c:8845
 do_perf_sw_event kernel/events/core.c:9062 [inline]
 ___perf_sw_event+0x41f/0x550 kernel/events/core.c:9093
 __perf_sw_event+0x13e/0x230 kernel/events/core.c:9105
 mm_account_fault include/linux/perf_event.h:1159 [inline]
 handle_mm_fault+0x1aea/0x29a0 mm/memory.c:4468
 do_user_addr_fault+0x515/0xa90 arch/x86/mm/fault.c:1294
 handle_page_fault arch/x86/mm/fault.c:1351 [inline]
 exc_page_fault+0x124/0x1f0 arch/x86/mm/fault.c:1404
 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:ffffc9000a907ac0 EFLAGS: 00010206
RAX: ffffffff839e3201 RBX: 0000000020f8cfcb RCX: 0000000000007fcb
RDX: 0000000000008000 RSI: 0000000020f85000 RDI: ffff888034ef0035
RBP: ffff888034ef0000 R08: dffffc0000000000 R09: ffffed10069df000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000008000
R13: 0000000020f84fcb R14: ffffc9000a907dd8 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:153 [inline]
 _copy_from_iter_full+0x2ba/0xaa0 lib/iov_iter.c:791
 copy_from_iter_full include/linux/uio.h:155 [inline]
 skb_do_copy_data_nocache+0xf6/0x2f0 include/net/sock.h:2038
 skb_copy_to_page_nocache include/net/sock.h:2064 [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:651 [inline]
 sock_sendmsg net/socket.c:671 [inline]
 __sys_sendto+0x42a/0x5c0 net/socket.c:1992
 __do_sys_sendto net/socket.c:2004 [inline]
 __se_sys_sendto net/socket.c:2000 [inline]
 __x64_sys_sendto+0xda/0xf0 net/socket.c:2000
 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45d239
Code: 5d 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 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fe3e1ab5c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 000000000002c380 RCX: 000000000045d239
RDX: ffffffffffffffef RSI: 0000000020d7cfcb RDI: 0000000000000007
RBP: 000000000118cf98 R08: 0000000000000000 R09: 0000000000000053
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c
R13: 00007ffca448987f R14: 00007fe3e1ab69c0 R15: 000000000118cf4c