rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (10499 ticks this GP) idle=1b6/1/0x4000000000000000 softirq=48222/48222 fqs=5164 
	(t=10500 jiffies g=77385 q=2097)
NMI backtrace for cpu 1
CPU: 1 PID: 21529 Comm: syz-executor.2 Not tainted 5.12.0-rc8-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:79 [inline]
 dump_stack+0x202/0x31e lib/dump_stack.c:120
 nmi_cpu_backtrace+0x16c/0x190 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x191/0x2f0 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x22d/0x390 kernel/rcu/tree_stall.h:341
 print_cpu_stall kernel/rcu/tree_stall.h:622 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:697 [inline]
 rcu_pending kernel/rcu/tree.c:3830 [inline]
 rcu_sched_clock_irq+0x1cd7/0x29f0 kernel/rcu/tree.c:2650
 update_process_times+0x197/0x200 kernel/time/timer.c:1796
 tick_sched_handle kernel/time/tick-sched.c:226 [inline]
 tick_sched_timer+0x27d/0x420 kernel/time/tick-sched.c:1369
 __run_hrtimer kernel/time/hrtimer.c:1537 [inline]
 __hrtimer_run_queues+0x4cb/0xa60 kernel/time/hrtimer.c:1601
 hrtimer_interrupt+0x3b3/0x1040 kernel/time/hrtimer.c:1663
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline]
 __sysvec_apic_timer_interrupt+0xf9/0x270 arch/x86/kernel/apic/apic.c:1106
 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632
RIP: 0010:memcpy_erms+0x8/0x10 arch/x86/lib/memcpy_64.S:56
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:ffffc900090e6cd8 EFLAGS: 00000202
RAX: ffff88802726c228 RBX: 0000000000000010 RCX: 0000000000000000
RDX: 0000000000000010 RSI: ffffc900090e6dd0 RDI: ffff88802726c238
RBP: ffffc900090e6e70 R08: dffffc0000000000 R09: ffffed1004e4d847
R10: ffffed1004e4d847 R11: 0000000000000000 R12: ffffc900090e7168
R13: 0000000000000010 R14: dffffc0000000000 R15: ffffc900090e7158
 memcpy_common kernel/events/internal.h:174 [inline]
 __output_copy kernel/events/internal.h:178 [inline]
 perf_output_read_group kernel/events/core.c:6766 [inline]
 perf_output_read+0x1130/0x1460 kernel/events/core.c:6799
 perf_output_sample+0x340/0x2310 kernel/events/core.c:6846
 __perf_event_output kernel/events/core.c:7331 [inline]
 perf_event_output_forward+0x178/0x250 kernel/events/core.c:7345
 __perf_event_overflow+0x1b9/0x340 kernel/events/core.c:9019
 do_perf_sw_event kernel/events/core.c:9236 [inline]
 ___perf_sw_event+0x4b5/0x630 kernel/events/core.c:9267
 __perf_sw_event+0x13f/0x270 kernel/events/core.c:9279
 mm_account_fault include/linux/perf_event.h:1169 [inline]
 handle_mm_fault+0x228f/0x2620 mm/memory.c:4565
 do_user_addr_fault+0x8ce/0x1120 arch/x86/mm/fault.c:1390
 handle_page_fault arch/x86/mm/fault.c:1475 [inline]
 exc_page_fault+0xa1/0x1e0 arch/x86/mm/fault.c:1531
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:577
RIP: 0010:copy_user_enhanced_fast_string+0xe/0x40 arch/x86/lib/copy_user_64.S:206
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 83 f8
RSP: 0018:ffffc900090e7928 EFLAGS: 00010206
RAX: ffffffff83f3f801 RBX: ffff8880615a0000 RCX: 0000000000000fcb
RDX: 0000000000008000 RSI: 0000000020fa4000 RDI: ffff8880615a7035
RBP: 0000000000008000 R08: dffffc0000000000 R09: ffffed100c2b5000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000008000
R13: ffffc900090e7e80 R14: 0000000020f9cfcb R15: 00007ffffffff000
 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline]
 raw_copy_from_user arch/x86/include/asm/uaccess_64.h:52 [inline]
 copyin lib/iov_iter.c:157 [inline]
 _copy_from_iter_full+0x2ac/0x950 lib/iov_iter.c:781
 copy_from_iter_full include/linux/uio.h:155 [inline]
 skb_do_copy_data_nocache+0x12e/0x340 include/net/sock.h:2071
 skb_copy_to_page_nocache include/net/sock.h:2097 [inline]
 tcp_sendmsg_locked+0x18b1/0x40a0 net/ipv4/tcp.c:1360
 tcp_sendmsg+0x2c/0x40 net/ipv4/tcp.c:1457
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg net/socket.c:674 [inline]
 __sys_sendto+0x541/0x720 net/socket.c:1977
 __do_sys_sendto net/socket.c:1989 [inline]
 __se_sys_sendto net/socket.c:1985 [inline]
 __x64_sys_sendto+0xda/0xf0 net/socket.c:1985
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x466459
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fab86535188 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459
RDX: ffffffffffffffef RSI: 0000000020d7cfcb RDI: 0000000000000007
RBP: 00000000004bfb23 R08: 0000000000000000 R09: 0000000000000053
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60
R13: 00007ffc1a7ded9f R14: 00007fab86535300 R15: 0000000000022000