rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=5494/1/0x4000000000000000 softirq=76624/76625 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P14990/1:b..l rcu: (detected by 0, t=10505 jiffies, g=69125, q=93 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 14988 Comm: syz.0.2450 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:check_preemption_disabled+0x0/0xe0 lib/smp_processor_id.c:13 Code: c0 75 0f 65 8b 05 7c 44 41 08 85 c0 74 04 90 0f 0b 90 e9 53 fc ff ff 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <41> 54 55 53 48 83 ec 08 65 8b 1d f5 05 41 08 65 8b 05 ea 05 41 08 RSP: 0018:ffffc90000a08dd8 EFLAGS: 00000083 RAX: 0000000000000000 RBX: ffff8880b8527c98 RCX: ffffffff81a95e41 RDX: 0000000000000000 RSI: ffffffff8db19a48 RDI: ffffffff8bf06cc0 RBP: 0000000000000046 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffffffff81a98489 R13: 0000000000000083 R14: ffff888077d54900 R15: ffffffff896c20c0 FS: 00007f4938df66c0(0000) GS:ffff888124b0b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b300fcff8 CR3: 0000000032166000 CR4: 00000000003526f0 Call Trace: lockdep_recursion_inc kernel/locking/lockdep.c:465 [inline] lock_release+0x9c/0x2f0 kernel/locking/lockdep.c:5888 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline] _raw_spin_unlock_irqrestore+0x1a/0x80 kernel/locking/spinlock.c:194 __run_hrtimer kernel/time/hrtimer.c:1773 [inline] __hrtimer_run_queues+0x529/0xad0 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline] __sysvec_apic_timer_interrupt+0x10b/0x3f0 arch/x86/kernel/apic/apic.c:1058 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:194 Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 16 f9 35 f6 48 89 df e8 fe 4c 36 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 45 56 26 f6 65 8b 05 7e 65 3e 08 85 c0 74 16 5b RSP: 0018:ffffc90003197c98 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffff8880b8427c80 RCX: 0000000000000007 RDX: 0000000000000000 RSI: ffffffff8da2a184 RDI: ffffffff8bf06cc0 RBP: 0000000000000283 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff9081f4d7 R11: 0000000000000001 R12: 0000000000000004 R13: 1bc16cb5d4d41372 R14: dffffc0000000000 R15: ffff8880b8427c80 clock_was_set+0x599/0x870 kernel/time/hrtimer.c:965 do_settimeofday64+0x364/0x550 kernel/time/timekeeping.c:1460 do_sys_settimeofday64+0x1dc/0x260 kernel/time/time.c:195 __do_sys_clock_settime kernel/time/posix-timers.c:1131 [inline] __se_sys_clock_settime kernel/time/posix-timers.c:1115 [inline] __x64_sys_clock_settime+0x1c1/0x2a0 kernel/time/posix-timers.c:1115 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f493ab8efc9 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:00007f4938df6038 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3 RAX: ffffffffffffffda RBX: 00007f493ade6090 RCX: 00007f493ab8efc9 RDX: 0000000000000000 RSI: 0000200000000040 RDI: 0000000000000000 RBP: 00007f493ac11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f493ade6128 R14: 00007f493ade6090 R15: 00007fff0293cf18 task:syz.2.2451 state:R running task stack:26584 pid:14990 tgid:14989 ppid:5812 task_flags:0x400140 flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7256 irqentry_exit+0x36/0x90 kernel/entry/common.c:211 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5872 Code: 65 08 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 32 0a e9 0e 0f 82 74 02 00 00 8b 35 aa 3a e9 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 49 65 08 12 0f 85 c7 02 00 00 48 83 c4 RSP: 0018:ffffc900025ef608 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff8e3c4460 RCX: 00000000704cbb28 RDX: 0000000000000000 RSI: ffffffff8da047c8 RDI: ffffffff8bf06cc0 RBP: 0000000000000002 R08: fd5b3b4fdb4dbf52 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] ___pte_offset_map+0x44/0x4f0 mm/pgtable-generic.c:286 __pte_offset_map include/linux/mm.h:3118 [inline] __pte_offset_map_lock+0x8d/0x310 mm/pgtable-generic.c:397 pte_offset_map_lock include/linux/mm.h:3133 [inline] finish_fault+0x6b2/0x1070 mm/memory.c:5545 do_read_fault mm/memory.c:5702 [inline] do_fault mm/memory.c:5832 [inline] do_pte_missing+0xf77/0x3ba0 mm/memory.c:4361 handle_pte_fault mm/memory.c:6177 [inline] __handle_mm_fault+0x1556/0x2aa0 mm/memory.c:6318 handle_mm_fault+0x589/0xd10 mm/memory.c:6487 faultin_page mm/gup.c:1126 [inline] __get_user_pages+0x54e/0x3530 mm/gup.c:1428 populate_vma_page_range+0x267/0x3f0 mm/gup.c:1860 __mm_populate+0x1d8/0x380 mm/gup.c:1963 mm_populate include/linux/mm.h:3471 [inline] vm_mmap_pgoff+0x37f/0x470 mm/util.c:586 ksys_mmap_pgoff+0x7d/0x5c0 mm/mmap.c:604 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline] __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f893898efc9 RSP: 002b:00007f89398d4038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f8938be5fa0 RCX: 00007f893898efc9 RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000 RBP: 00007f8938a11f91 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8938be6038 R14: 00007f8938be5fa0 R15: 00007ffe33923f58 rcu: rcu_preempt kthread starved for 10505 jiffies! g69125 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:28080 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7026 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: 17 6d 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 43 e5 29 00 fb f4 3c 0a 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e007df8 EFLAGS: 000002c6 RAX: 0000000003c6cc9f RBX: 0000000000000000 RCX: ffffffff8b6042a9 RDX: 0000000000000000 RSI: ffffffff8da2a184 RDI: ffffffff8bf06cc0 RBP: fffffbfff1c12f40 R08: 0000000000000001 R09: ffffed1017086655 R10: ffff8880b84332ab R11: 0000000000000001 R12: 0000000000000000 R13: ffffffff8e097a00 R14: ffffffff9081f4d0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124a0b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b300efff8 CR3: 0000000032166000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x38d/0x500 kernel/sched/idle.c:330 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428 rest_init+0x16b/0x2b0 init/main.c:757 start_kernel+0x3f6/0x4e0 init/main.c:1111 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x148