rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (10499 ticks this GP) idle=762/1/0x4000000000000000 softirq=13236/13236 fqs=5226 (t=10500 jiffies g=16473 q=1702) NMI backtrace for cpu 0 CPU: 0 PID: 10540 Comm: syz-executor.1 Not tainted 5.10.0-rc1-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+0x107/0x163 lib/dump_stack.c:118 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: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:3694 [inline] rcu_sched_clock_irq.cold+0x4db/0xded kernel/rcu/tree.c:2567 update_process_times+0x77/0xd0 kernel/time/timer.c:1714 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 __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:631 RIP: 0010:check_kcov_mode kernel/kcov.c:163 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x19/0x60 kernel/kcov.c:197 Code: 8b 54 24 08 48 8b 34 24 e9 a1 fd ff ff 0f 1f 40 00 65 48 8b 14 25 00 f0 01 00 65 8b 05 70 e6 91 7e a9 00 01 ff 00 48 8b 34 24 <74> 0f f6 c4 01 74 35 8b 82 54 14 00 00 85 c0 74 2b 8b 82 30 14 00 RSP: 0018:ffffc900080c6fd0 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffffc900080c7320 RCX: ffffffff818b9461 RDX: ffff8880273c2100 RSI: ffffffff818b950a RDI: 0000000000000007 RBP: 0000000000000000 R08: 0000000000000001 R09: ffff8880157682bf R10: 0000000000000000 R11: 0000000000000001 R12: ffffc900080c7120 R13: dffffc0000000000 R14: 0000000000000d40 R15: 0000000000000010 __output_copy kernel/events/internal.h:178 [inline] perf_output_read_group kernel/events/core.c:6744 [inline] perf_output_read+0xe5a/0x1310 kernel/events/core.c:6777 perf_output_sample+0x102c/0x1b60 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:4570 [inline] handle_mm_fault+0x10cf/0x55d0 mm/memory.c:4621 do_user_addr_fault+0x55b/0xb40 arch/x86/mm/fault.c:1372 handle_page_fault arch/x86/mm/fault.c:1429 [inline] exc_page_fault+0x9e/0x180 arch/x86/mm/fault.c:1485 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:583 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:ffffc900080c79d0 EFLAGS: 00010206 RAX: 0000000000000001 RBX: 0000000000008000 RCX: 0000000000001fcb RDX: 0000000000008000 RSI: 0000000020ed3000 RDI: ffff88806a33e035 RBP: ffff88806a338000 R08: 0000000000000001 R09: ffff88806a33ffff R10: ffffed100d467fff R11: 0000000000000000 R12: 0000000020eccfcb R13: 0000000020ed4fcb R14: 0000000000000000 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.part.0+0xe4/0x110 lib/iov_iter.c:159 copyin lib/iov_iter.c:795 [inline] _copy_from_iter_full+0x22f/0x920 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:2036 skb_copy_to_page_nocache include/net/sock.h:2062 [inline] tcp_sendmsg_locked+0x12ea/0x2d30 net/ipv4/tcp.c:1345 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:00007f11d61b8c78 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: 00007fff087d771f R14: 00007f11d61b99c0 R15: 000000000118bf2c