rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (10496 ticks this GP) idle=61a/1/0x4000000000000000 softirq=15006/15006 fqs=5242 
	(t=10502 jiffies g=20869 q=1563)
NMI backtrace for cpu 1
CPU: 1 PID: 10111 Comm: syz-executor.5 Not tainted 5.8.0-rc5-next-20200716-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+0x18f/0x20d lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:165 [inline]
 rcu_dump_cpu_stacks+0x194/0x1cf 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:3626 [inline]
 rcu_sched_clock_irq.cold+0x5b3/0xcbd kernel/rcu/tree.c:2509
 update_process_times+0x25/0x60 kernel/time/timer.c:1726
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:176
 tick_sched_timer+0x108/0x290 kernel/time/tick-sched.c:1328
 __run_hrtimer kernel/time/hrtimer.c:1520 [inline]
 __hrtimer_run_queues+0x1d5/0xfc0 kernel/time/hrtimer.c:1584
 hrtimer_interrupt+0x32a/0x930 kernel/time/hrtimer.c:1646
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1079 [inline]
 __sysvec_apic_timer_interrupt+0x142/0x5e0 arch/x86/kernel/apic/apic.c:1096
 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+0xe0/0x120 arch/x86/kernel/apic/apic.c:1090
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:587
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:107 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:134 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:165 [inline]
RIP: 0010:check_memory_region_inline mm/kasan/generic.c:183 [inline]
RIP: 0010:check_memory_region+0x5f/0x180 mm/kasan/generic.c:192
Code: 89 fd 48 b8 00 00 00 00 00 fc ff df 4d 89 ca 48 c1 ed 03 49 c1 ea 03 48 01 c5 49 01 c2 48 89 e8 49 8d 5a 01 48 89 da 48 29 ea <48> 83 fa 10 7e 63 41 89 eb 41 83 e3 07 75 74 4c 8d 5a 07 48 85 d2
RSP: 0018:ffffc900017d6f58 EFLAGS: 00000202
RAX: fffff520002fae1a RBX: fffff520002fae1c RCX: ffffffff818df158
RDX: 0000000000000002 RSI: 0000000000000010 RDI: ffffc900017d70d0
RBP: fffff520002fae1a R08: 0000000000000000 R09: ffffc900017d70df
R10: fffff520002fae1b R11: 0000000000000001 R12: 0000000000000010
R13: ffff8880539f40b8 R14: 1ffff920002fae61 R15: 0000000000000010
 memcpy+0x20/0x60 mm/kasan/common.c:105
 memcpy include/linux/string.h:406 [inline]
 memcpy_common kernel/events/internal.h:174 [inline]
 __output_copy kernel/events/internal.h:178 [inline]
 perf_output_read_group kernel/events/core.c:6701 [inline]
 perf_output_read+0xd38/0x1260 kernel/events/core.c:6734
 perf_output_sample+0x102c/0x1c60 kernel/events/core.c:6781
 __perf_event_output kernel/events/core.c:7162 [inline]
 perf_event_output_forward+0x12f/0x270 kernel/events/core.c:7176
 __perf_event_overflow+0x13c/0x370 kernel/events/core.c:8831
 perf_swevent_overflow kernel/events/core.c:8907 [inline]
 perf_swevent_event+0x347/0x550 kernel/events/core.c:8935
 do_perf_sw_event kernel/events/core.c:9048 [inline]
 ___perf_sw_event+0x304/0x550 kernel/events/core.c:9079
 __perf_sw_event+0x58/0x120 kernel/events/core.c:9091
 perf_sw_event include/linux/perf_event.h:1158 [inline]
 mm_account_fault mm/memory.c:4428 [inline]
 handle_mm_fault+0x1219/0x45e0 mm/memory.c:4479
 do_user_addr_fault+0x598/0xbf0 arch/x86/mm/fault.c:1294
 handle_page_fault arch/x86/mm/fault.c:1351 [inline]
 exc_page_fault+0xab/0x170 arch/x86/mm/fault.c:1404
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:544
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:ffffc900017d79b8 EFLAGS: 00010206
RAX: 0000000000000001 RBX: 0000000000008000 RCX: 0000000000007fcb
RDX: 0000000000008000 RSI: 0000000020f95000 RDI: ffff88804bdc0035
RBP: ffff88804bdc0000 R08: 0000000000000001 R09: ffff88804bdc7fff
R10: ffffed10097b8fff R11: 0000000000000000 R12: 0000000020f94fcb
R13: 0000000020f9cfcb 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+0x1ff/0x890 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:2051
 skb_copy_to_page_nocache include/net/sock.h:2077 [inline]
 tcp_sendmsg_locked+0x112c/0x2d00 net/ipv4/tcp.c:1343
 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1441
 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:1994
 __do_sys_sendto net/socket.c:2006 [inline]
 __se_sys_sendto net/socket.c:2002 [inline]
 __x64_sys_sendto+0xdd/0x1b0 net/socket.c:2002
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45c1d9
Code: Bad RIP value.
RSP: 002b:00007f7d86101c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 000000000002b1c0 RCX: 000000000045c1d9
RDX: ffffffffffffffef RSI: 0000000020d7cfcb RDI: 0000000000000006
RBP: 000000000078bf58 R08: 0000000000000000 R09: 0000000000000053
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c
R13: 00007fff98f6c62f R14: 00007f7d861029c0 R15: 000000000078bf0c