rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (10499 ticks this GP) idle=f9a/1/0x4000000000000000 softirq=11367/11367 fqs=5182 
	(t=10500 jiffies g=14201 q=1961)
NMI backtrace for cpu 0
CPU: 0 PID: 8094 Comm: syz-executor.1 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+0x198/0x1fb lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1b3/0x230 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/0xdee kernel/rcu/tree.c:2521
 update_process_times+0x25/0xa0 kernel/time/timer.c:1712
 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+0x1ce/0xea0 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+0x146/0x540 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+0xbd/0x100 arch/x86/kernel/apic/apic.c:1091
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581
RIP: 0010:write_comp_data+0x2f/0x80 kernel/kcov.c:218
Code: 05 26 84 8d 7e 65 48 8b 34 25 c0 fe 01 00 a9 00 01 ff 00 74 0f f6 c4 01 74 59 8b 86 34 14 00 00 85 c0 74 4f 8b 86 10 14 00 00 <83> f8 03 75 44 48 8b 86 18 14 00 00 8b b6 14 14 00 00 4c 8b 00 48
RSP: 0018:ffffc90008b7ef90 EFLAGS: 00000246
RAX: 0000000000000002 RBX: ffffc90008b7f2e0 RCX: ffffffff818f1441
RDX: 0000000000000528 RSI: ffff888051a5a480 RDI: 0000000000000007
RBP: 0000000000000000 R08: 0000000000000001 R09: ffff88808e3cfad7
R10: 0000000000000000 R11: 0000000000000001 R12: ffffc90008b7f0e0
R13: dffffc0000000000 R14: 0000000000000528 R15: 0000000000000010
 __output_copy kernel/events/internal.h:178 [inline]
 perf_output_read_group kernel/events/core.c:6744 [inline]
 perf_output_read+0xdb1/0x1310 kernel/events/core.c:6777
 perf_output_sample+0x102c/0x1c60 kernel/events/core.c:6824
 __perf_event_output kernel/events/core.c:7205 [inline]
 perf_event_output_forward+0x12f/0x270 kernel/events/core.c:7219
 __perf_event_overflow+0x13c/0x370 kernel/events/core.c:8874
 perf_swevent_overflow kernel/events/core.c:8950 [inline]
 perf_swevent_event+0x347/0x550 kernel/events/core.c:8978
 do_perf_sw_event kernel/events/core.c:9091 [inline]
 ___perf_sw_event+0x31a/0x570 kernel/events/core.c:9122
 __perf_sw_event+0x54/0x130 kernel/events/core.c:9134
 perf_sw_event include/linux/perf_event.h:1171 [inline]
 mm_account_fault mm/memory.c:4563 [inline]
 handle_mm_fault+0x1219/0x4630 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/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:ffffc90008b7f9c8 EFLAGS: 00010206
RAX: 0000000000000001 RBX: 0000000000008000 RCX: 0000000000006fcb
RDX: 0000000000008000 RSI: 0000000020f7e000 RDI: ffff88805b5c1035
RBP: ffff88805b5c0000 R08: 0000000000000001 R09: ffff88805b5c7fff
R10: ffffed100b6b8fff R11: 0000000000000000 R12: 0000000020f7cfcb
R13: 0000000020f84fcb 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:52 [inline]
 copyin+0x107/0x140 lib/iov_iter.c:154
 _copy_from_iter_full+0x206/0x8a0 lib/iov_iter.c:790
 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:00007f0d929a7c78 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: 00007ffc73923d8f R14: 00007f0d929a89c0 R15: 000000000118bf2c