rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (1 GPs behind) idle=543/1/0x4000000000000000 softirq=18712/18714 fqs=4 (t=10500 jiffies g=19745 q=626) rcu: rcu_preempt kthread starved for 10490 jiffies! g19745 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:26176 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5029 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6375 schedule+0x11b/0x1f0 kernel/sched/core.c:6458 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 7443 Comm: syz.0.678 Not tainted 5.15.179-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:27 [inline] RIP: 0010:static_key_false include/linux/jump_label.h:212 [inline] RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:156 [inline] RIP: 0010:wrmsr arch/x86/include/asm/msr.h:263 [inline] RIP: 0010:native_apic_msr_write+0x35/0x50 arch/x86/include/asm/apic.h:208 Code: 74 2a 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 <66> 90 c3 89 f6 31 d2 e9 ef d3 fe 02 66 2e 0f 1f 84 00 00 00 00 00 RSP: 0018:ffffc90002f2f8c0 EFLAGS: 00000046 RAX: 000000000000003e RBX: ffffffff8c5ce9c8 RCX: 0000000000000838 RDX: 0000000000000000 RSI: 000000000000003e RDI: 0000000000000838 RBP: 0000000000000020 R08: ffffffff8172a538 R09: fffffbfff1c153f6 R10: 0000000000000000 R11: dffffc0000000001 R12: 000000000000003e R13: dffffc0000000000 R14: 000000000000003e R15: dffffc0000000000 FS: 000055556a410500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb5bb046b30 CR3: 0000000067594000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: apic_write arch/x86/include/asm/apic.h:395 [inline] lapic_next_event+0x5b/0x70 arch/x86/kernel/apic/apic.c:468 clockevents_program_min_delta+0x1ae/0x410 kernel/time/clockevents.c:248 hrtimer_start_range_ns+0xada/0xc80 kernel/time/hrtimer.c:1302 posixtimer_rearm+0x1ad/0x3f0 kernel/time/posix-timers.c:328 dequeue_signal+0x1ed/0x520 kernel/signal.c:696 get_signal+0x52e/0x14e0 kernel/signal.c:2781 arch_do_signal_or_restart+0xc3/0x1890 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fe67501d169 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffea065dff8 EFLAGS: 00000246 RAX: fffffffffffffffc RBX: 00000000000627e2 RCX: 00007fe67501d169 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fe675235fac RBP: 0000000000000032 R08: 0000000000000010 R09: 00000007a065e2ef R10: 00007ffea065e0f0 R11: 0000000000000246 R12: 00007fe675235fac R13: 00007ffea065e0f0 R14: 0000000000062814 R15: 00007ffea065e110 NMI backtrace for cpu 1 CPU: 1 PID: 7423 Comm: syz.4.675 Not tainted 5.15.179-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline] rcu_dump_cpu_stacks+0x223/0x390 kernel/rcu/tree_stall.h:349 print_cpu_stall+0x320/0x600 kernel/rcu/tree_stall.h:633 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline] rcu_pending kernel/rcu/tree.c:3932 [inline] rcu_sched_clock_irq+0x8d9/0x1150 kernel/rcu/tree.c:2619 update_process_times+0x196/0x200 kernel/time/timer.c:1818 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1688 [inline] __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x13b/0x4b0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:copy_user_generic_unrolled+0xb1/0xc0 arch/x86/lib/copy_user_64.S:108 Code: 8b 06 4c 89 07 48 8d 76 08 48 8d 7f 08 ff c9 75 ee 21 d2 74 10 89 d1 8a 06 88 07 48 ff c6 48 ff c7 ff c9 75 f2 31 c0 0f 01 ca 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 0f 01 cb 83 fa 08 72 RSP: 0018:ffffc900041cfd28 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00007fffc5b86e68 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 00007fffc5b86e68 RDI: ffffc900041cfdd8 RBP: ffffc900041cfe50 R08: 0000000000000000 R09: fffff52000839fbb R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000018 R13: 00007ffffffff000 R14: ffffc900041cfdc0 R15: 00007fffc5b86e50 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] _copy_from_user+0xf9/0x170 lib/usercopy.c:23 copy_from_user include/linux/uaccess.h:192 [inline] restore_altstack+0x9a/0x400 kernel/signal.c:4252 __do_sys_rt_sigreturn+0x19d/0x250 arch/x86/kernel/signal.c:677 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f7acd376590 Code: 72 48 39 f0 0f 82 b9 00 00 00 48 39 f2 72 6e 41 0f 11 0c 24 48 8b 77 f8 48 89 f8 48 89 eb eb 12 66 2e 0f 1f 84 00 00 00 00 00 <48> 8b 4b 08 48 83 c3 08 48 39 d1 72 f3 48 83 e8 08 48 39 f2 73 17 RSP: 002b:00007fffc5b873d0 EFLAGS: 00000293 RAX: 00007f7acc7966c8 RBX: 00007f7acc796580 RCX: ffffffff81c29252 RDX: ffffffff81c292e4 RSI: ffffffff81c4009e RDI: 00007f7acc7966c8 RBP: 00007f7acc796580 R08: 00007f7acc796620 R09: 00007f7acd6a2000 R10: 00007f7acc70d008 R11: 000000000000000b R12: 00007f7acc796578 R13: 0000000000000012 R14: 00000000000632d4 R15: 00007f7acc70d008