rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (10499 ticks this GP) idle=3da/1/0x4000000000000002 softirq=44568/44568 fqs=5225 (t=10501 jiffies g=86109 q=4346) NMI backtrace for cpu 0 CPU: 0 PID: 19333 Comm: syz-executor.5 Not tainted 5.6.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x188/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x231/0x27e lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x19b/0x1e5 kernel/rcu/tree_stall.h:254 print_cpu_stall kernel/rcu/tree_stall.h:475 [inline] check_cpu_stall kernel/rcu/tree_stall.h:549 [inline] rcu_pending kernel/rcu/tree.c:3225 [inline] rcu_sched_clock_irq.cold+0x55d/0xcfa kernel/rcu/tree.c:2296 update_process_times+0x25/0x60 kernel/time/timer.c:1727 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:176 tick_sched_timer+0x4e/0x140 kernel/time/tick-sched.c:1320 __run_hrtimer kernel/time/hrtimer.c:1520 [inline] __hrtimer_run_queues+0x5ca/0xed0 kernel/time/hrtimer.c:1584 hrtimer_interrupt+0x312/0x770 kernel/time/hrtimer.c:1646 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1113 [inline] smp_apic_timer_interrupt+0x15b/0x600 arch/x86/kernel/apic/apic.c:1138 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x50 kernel/kcov.c:192 Code: fa 8e 7e 81 e2 00 01 1f 00 48 8b 34 24 75 2b 8b 90 d8 13 00 00 83 fa 02 75 20 48 8b 88 e0 13 00 00 8b 80 dc 13 00 00 48 8b 11 <48> 83 c2 01 48 39 d0 76 07 48 89 34 d1 48 89 11 c3 0f 1f 84 00 00 RSP: 0018:ffffc90016dbf138 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000040000 RBX: ffffffff89892c80 RCX: ffffc900139f4000 RDX: 000000000003ffff RSI: ffffffff818bde07 RDI: 0000000000000007 RBP: 0000000000000bb8 R08: ffff88805b9d2500 R09: ffffed101374be3d R10: ffff88809ba5f1e7 R11: ffffed101374be3c R12: dffffc0000000000 R13: ffff88809ba5f000 R14: ffffc90016dbf298 R15: ffffc90016dbf498 perf_output_read_group kernel/events/core.c:6673 [inline] perf_output_read+0xe87/0x11f0 kernel/events/core.c:6712 perf_output_sample+0xe17/0x1c20 kernel/events/core.c:6759 __perf_event_output kernel/events/core.c:7137 [inline] perf_event_output_forward+0x12f/0x270 kernel/events/core.c:7151 __perf_event_overflow+0x13c/0x370 kernel/events/core.c:8716 perf_swevent_overflow+0xac/0x150 kernel/events/core.c:8792 perf_swevent_event+0x1e9/0x2e0 kernel/events/core.c:8825 do_perf_sw_event kernel/events/core.c:8933 [inline] ___perf_sw_event+0x31c/0x570 kernel/events/core.c:8964 __perf_sw_event+0x4b/0xa0 kernel/events/core.c:8976 perf_sw_event include/linux/perf_event.h:1158 [inline] do_user_addr_fault arch/x86/mm/fault.c:1501 [inline] do_page_fault+0xb07/0x13da arch/x86/mm/fault.c:1535 page_fault+0x39/0x40 arch/x86/entry/entry_64.S:1203 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 a4 31 c0 0f 1f 00 c3 66 2e 0f 1f 84 00 00 00 00 00 89 d1 f3 a4 RSP: 0018:ffffc90016dbfa58 EFLAGS: 00010206 RAX: 0000000000000001 RBX: 0000000000008000 RCX: 0000000000002fcb RDX: 0000000000008000 RSI: 0000000020fea000 RDI: ffff888049205035 RBP: ffff888049200000 R08: ffffed1009241000 R09: 0000000000000000 R10: ffff888049207fff R11: ffffed1009240fff R12: 0000000020fe4fcb R13: 0000000020fecfcb 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:151 _copy_from_iter_full+0x20a/0x870 lib/iov_iter.c:789 copy_from_iter_full include/linux/uio.h:156 [inline] skb_do_copy_data_nocache include/net/sock.h:2036 [inline] skb_copy_to_page_nocache include/net/sock.h:2062 [inline] tcp_sendmsg_locked+0x131a/0x3210 net/ipv4/tcp.c:1335 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1433 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:807 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 __sys_sendto+0x220/0x330 net/socket.c:2000 __do_sys_sendto net/socket.c:2012 [inline] __se_sys_sendto net/socket.c:2008 [inline] __x64_sys_sendto+0xdd/0x1b0 net/socket.c:2008 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45c889 Code: ad b6 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f7583f9dc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f7583f9e6d4 RCX: 000000000045c889 RDX: ffffffffffffffef RSI: 0000000020d7cfcb RDI: 0000000000000006 RBP: 000000000076bf00 R08: 0000000000000000 R09: 0f0000000000e803 R10: 00000000000001f4 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000a06 R14: 00000000004ccc06 R15: 000000000076bf0c