rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (10500 ticks this GP) idle=bfe/1/0x4000000000000000 softirq=12100/12100 fqs=5238 (t=10502 jiffies g=14857 q=1667) NMI backtrace for cpu 0 CPU: 0 PID: 9966 Comm: syz-executor.2 Not tainted 5.12.0-rc2-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+0x141/0x1d7 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:164 [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:3830 [inline] rcu_sched_clock_irq.cold+0x4f7/0x11dd kernel/rcu/tree.c:2650 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:1089 [inline] __sysvec_apic_timer_interrupt+0x146/0x540 arch/x86/kernel/apic/apic.c:1106 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632 RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x60 kernel/kcov.c:197 Code: 81 e1 00 01 00 00 65 48 8b 14 25 00 f0 01 00 a9 00 01 ff 00 74 0e 85 c9 74 35 8b 82 d4 14 00 00 85 c0 74 2b 8b 82 b0 14 00 00 <83> f8 02 75 20 48 8b 8a b8 14 00 00 8b 92 b4 14 00 00 48 8b 01 48 RSP: 0018:ffffc900019cf110 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffffc900019cf460 RCX: 0000000000000000 RDX: ffff88806432e380 RSI: ffffffff819072fa RDI: ffff888026bd4010 RBP: 0000000000000000 R08: 0000000000000000 R09: ffff888013705ca7 R10: ffffffff819075a4 R11: 0000000000000001 R12: ffffc900019cf260 R13: dffffc0000000000 R14: 0000000000000358 R15: 0000000000000010 perf_output_read_group kernel/events/core.c:6725 [inline] perf_output_read+0xbba/0x1310 kernel/events/core.c:6766 perf_output_sample+0xd12/0x1be0 kernel/events/core.c:6813 __perf_event_output kernel/events/core.c:7298 [inline] perf_event_output_forward+0x132/0x270 kernel/events/core.c:7312 __perf_event_overflow+0x13c/0x370 kernel/events/core.c:8986 perf_swevent_overflow kernel/events/core.c:9062 [inline] perf_swevent_event+0x347/0x550 kernel/events/core.c:9090 do_perf_sw_event kernel/events/core.c:9203 [inline] ___perf_sw_event+0x31a/0x570 kernel/events/core.c:9234 __perf_sw_event+0x54/0x130 kernel/events/core.c:9246 perf_sw_event include/linux/perf_event.h:1167 [inline] mm_account_fault mm/memory.c:4512 [inline] handle_mm_fault+0x5da/0x7e0 mm/memory.c:4563 do_user_addr_fault+0x483/0x1210 arch/x86/mm/fault.c:1390 handle_page_fault arch/x86/mm/fault.c:1475 [inline] exc_page_fault+0x9e/0x180 arch/x86/mm/fault.c:1531 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:577 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:ffffc900019cf9c0 EFLAGS: 00010206 RAX: 0000000000000001 RBX: 0000000000008000 RCX: 0000000000001fcb RDX: 0000000000008000 RSI: 0000000020f4b000 RDI: ffff88806a366035 RBP: ffff88806a360000 R08: 0000000000000001 R09: ffff88806a367fff R10: ffffed100d46cfff R11: 0000000000000000 R12: 0000000020f44fcb R13: 0000000020f4cfcb R14: 0000000000000000 R15: 0000000000008000 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:157 copyin lib/iov_iter.c:781 [inline] _copy_from_iter_full+0x228/0x8a0 lib/iov_iter.c:781 copy_from_iter_full include/linux/uio.h:155 [inline] skb_do_copy_data_nocache+0x145/0x2c0 include/net/sock.h:2067 skb_copy_to_page_nocache include/net/sock.h:2093 [inline] tcp_sendmsg_locked+0x1360/0x2e40 net/ipv4/tcp.c:1360 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1457 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:821 sock_sendmsg_nosec net/socket.c:654 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:674 __sys_sendto+0x21c/0x320 net/socket.c:1977 __do_sys_sendto net/socket.c:1989 [inline] __se_sys_sendto net/socket.c:1985 [inline] __x64_sys_sendto+0xdd/0x1b0 net/socket.c:1985 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x465f69 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fdaf44f8188 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465f69 RDX: ffffffffffffffef RSI: 0000000020d7cfcb RDI: 0000000000000007 RBP: 00000000004bfa67 R08: 0000000000000000 R09: 0000000000000053 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffd8c78d34f R14: 00007fdaf44f8300 R15: 0000000000022000