rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-....: (10499 ticks this GP) idle=732/1/0x4000000000000000 softirq=13715/13716 fqs=5198 (t=10500 jiffies g=14949 q=1957) NMI backtrace for cpu 1 CPU: 1 PID: 10126 Comm: syz-executor.0 Not tainted 5.11.0-rc3-next-20210115-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:165 [inline] rcu_dump_cpu_stacks+0x222/0x2a7 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:3802 [inline] rcu_sched_clock_irq.cold+0x522/0x1252 kernel/rcu/tree.c:2622 update_process_times+0x16d/0x200 kernel/time/timer.c:1796 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1369 __run_hrtimer kernel/time/hrtimer.c:1519 [inline] __hrtimer_run_queues+0x1c0/0xe40 kernel/time/hrtimer.c:1583 hrtimer_interrupt+0x334/0x940 kernel/time/hrtimer.c:1645 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline] __sysvec_apic_timer_interrupt+0x146/0x540 arch/x86/kernel/apic/apic.c:1102 asm_call_irq_on_stack+0xf/0x20 __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:1096 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:628 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 0f 1f 80 00 00 00 00 48 89 f8 48 83 fa 20 72 7e 40 38 fe 7c 35 RSP: 0018:ffffc90001c57010 EFLAGS: 00000202 RAX: ffff88802a85ec68 RBX: ffffc90001c57360 RCX: 0000000000000000 RDX: 0000000000000010 RSI: ffffc90001c57160 RDI: ffff88802a85ec78 RBP: 0000000000000000 R08: 0000000000000001 R09: ffff88802a85ec77 R10: ffffed100550bd8e R11: 0000000000000001 R12: ffffc90001c57150 R13: dffffc0000000000 R14: 1ffff9200038ae71 R15: 0000000000000010 memcpy include/linux/fortify-string.h:191 [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:6744 [inline] perf_output_read+0xd7a/0x1310 kernel/events/core.c:6777 perf_output_sample+0xd12/0x1be0 kernel/events/core.c:6824 __perf_event_output kernel/events/core.c:7309 [inline] perf_event_output_forward+0x132/0x270 kernel/events/core.c:7323 __perf_event_overflow+0x13c/0x370 kernel/events/core.c:8979 perf_swevent_overflow kernel/events/core.c:9055 [inline] perf_swevent_event+0x347/0x550 kernel/events/core.c:9083 do_perf_sw_event kernel/events/core.c:9196 [inline] ___perf_sw_event+0x31a/0x570 kernel/events/core.c:9227 __perf_sw_event+0x54/0x130 kernel/events/core.c:9239 perf_sw_event include/linux/perf_event.h:1167 [inline] mm_account_fault mm/memory.c:4583 [inline] handle_mm_fault+0x10c8/0x5690 mm/memory.c:4634 do_user_addr_fault+0x458/0xc60 arch/x86/mm/fault.c:1399 handle_page_fault arch/x86/mm/fault.c:1456 [inline] exc_page_fault+0x9e/0x180 arch/x86/mm/fault.c:1512 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:580 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 a4 31 c0 0f 1f 00 c3 66 2e 0f 1f 84 00 00 00 00 00 89 d1 83 f8 RSP: 0018:ffffc90001c579c8 EFLAGS: 00010206 RAX: 0000000000000001 RBX: 0000000000008000 RCX: 0000000000000fcb RDX: 0000000000008000 RSI: 0000000020ff4000 RDI: ffff888014dcf035 RBP: ffff888014dc8000 R08: 0000000000000001 R09: ffff888014dcffff R10: ffffed10029b9fff R11: 0000000000000000 R12: 0000000020fecfcb R13: 0000000020ff4fcb R14: 0000000000000000 R15: ffffc90001c57da8 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.part.0+0xe4/0x110 lib/iov_iter.c:159 copyin lib/iov_iter.c:795 [inline] _copy_from_iter_full+0x228/0x850 lib/iov_iter.c:795 copy_from_iter_full include/linux/uio.h:155 [inline] skb_do_copy_data_nocache+0x145/0x2c0 include/net/sock.h:2054 skb_copy_to_page_nocache include/net/sock.h:2080 [inline] tcp_sendmsg_locked+0x1360/0x2e40 net/ipv4/tcp.c:1362 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1459 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:817 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 __sys_sendto+0x21c/0x320 net/socket.c:1975 __do_sys_sendto net/socket.c:1987 [inline] __se_sys_sendto net/socket.c:1983 [inline] __x64_sys_sendto+0xdd/0x1b0 net/socket.c:1983 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45e219 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:00007fcbf05e2c68 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 000000000045e219 RDX: ffffffffffffffef RSI: 0000000020d7cfcb RDI: 0000000000000006 RBP: 000000000119bfd8 R08: 0000000000000000 R09: 0000000000000053 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119bf8c R13: 00007ffd50b3f1bf R14: 00007fcbf05e39c0 R15: 000000000119bf8c