rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P17803/1:b..l rcu: (detected by 0, t=10505 jiffies, g=116549, q=270 ncpus=2) task:syz.0.3896 state:R running task stack:25784 pid:17803 tgid:17802 ppid:5611 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1295/0x67a0 kernel/sched/core.c:7189 preempt_schedule_common+0x42/0xc0 kernel/sched/core.c:7370 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:190 spin_unlock include/linux/spinlock.h:390 [inline] wp_page_copy mm/memory.c:3960 [inline] do_wp_page+0x13d2/0x4350 mm/memory.c:4320 handle_pte_fault mm/memory.c:6427 [inline] __handle_mm_fault+0x1ab6/0x2a00 mm/memory.c:6549 handle_mm_fault+0x36d/0xa20 mm/memory.c:6718 do_user_addr_fault+0x74c/0x12f0 arch/x86/mm/fault.c:1385 handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1527 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0010:rep_movs_alternative+0x4a/0x90 arch/x86/lib/copy_user_64.S:74 Code: 9b 04 00 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 8b 06 48 89 07 48 83 c6 08 48 83 c7 08 83 e9 08 74 db 83 f9 08 73 e8 eb c5 a4 c3 cc cc cc cc 48 8b 06 48 89 07 48 8d 47 08 48 83 e0 f8 48 RSP: 0018:ffffc9000764f920 EFLAGS: 00050206 RAX: 0000000000000001 RBX: 0000000000001000 RCX: 0000000000000e80 RDX: 0000000000000001 RSI: ffff8880140f5180 RDI: 0000200000381000 RBP: ffffc9000764fd30 R08: 0000000000000000 R09: ffffed100281ebff R10: ffff8880140f5fff R11: 0000000000000000 R12: ffff8880140f5000 R13: 0000000000380b80 R14: 0000200000380e80 R15: 0000000000001000 copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:147 [inline] copy_to_user_iter lib/iov_iter.c:25 [inline] iterate_iovec include/linux/iov_iter.h:52 [inline] iterate_and_advance2 include/linux/iov_iter.h:304 [inline] iterate_and_advance include/linux/iov_iter.h:330 [inline] _copy_to_iter+0x4c5/0x1720 lib/iov_iter.c:197 copy_page_to_iter lib/iov_iter.c:374 [inline] copy_page_to_iter+0x285/0x370 lib/iov_iter.c:361 process_vm_rw_pages mm/process_vm_access.c:45 [inline] process_vm_rw_single_vec mm/process_vm_access.c:118 [inline] process_vm_rw_core.constprop.0+0x5a3/0x950 mm/process_vm_access.c:216 process_vm_rw+0x309/0x370 mm/process_vm_access.c:284 __do_sys_process_vm_readv mm/process_vm_access.c:296 [inline] __se_sys_process_vm_readv mm/process_vm_access.c:292 [inline] __x64_sys_process_vm_readv+0xe2/0x1c0 mm/process_vm_access.c:292 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f757379ce59 RSP: 002b:00007f75745d0028 EFLAGS: 00000246 ORIG_RAX: 0000000000000136 RAX: ffffffffffffffda RBX: 00007f7573a15fa0 RCX: 00007f757379ce59 RDX: 0000000000000002 RSI: 0000200000008400 RDI: 0000000000000879 RBP: 00007f7573832d6f R08: 0000000000000286 R09: 0000000000000000 R10: 0000200000008640 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7573a16038 R14: 00007f7573a15fa0 R15: 00007ffd30b0e478 rcu: rcu_preempt kthread timer wakeup didn't happen for 10500 jiffies! g116549 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=47764 rcu: rcu_preempt kthread starved for 10501 jiffies! g116549 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1 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:I stack:27992 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1295/0x67a0 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7283 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 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: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 17827 Comm: syz.1.3901 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:146 [inline] RIP: 0010:lock_acquire kernel/locking/lockdep.c:5869 [inline] RIP: 0010:lock_acquire+0x187/0x370 kernel/locking/lockdep.c:5825 Code: 9c 8f 04 24 fa 48 c7 c7 e8 3a 01 8e e8 02 6a a6 09 45 89 e8 44 89 e1 89 da 65 ff 05 4b e8 26 12 4c 8b 14 24 44 89 f6 48 89 ef <41> 81 e2 00 02 00 00 4c 89 14 24 4d 89 d1 6a 00 49 c1 e9 09 6a 00 RSP: 0018:ffffc90000a08d10 EFLAGS: 00000002 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff9b3ef7b8 RBP: ffffffff9b3ef7b8 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000046 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f6ad78be6c0(0000) GS:ffff88812446d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3361bff8 CR3: 0000000052001000 CR4: 00000000003526f0 Call Trace: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:166 debug_object_deactivate+0x135/0x3b0 lib/debugobjects.c:890 debug_hrtimer_deactivate kernel/time/hrtimer.c:490 [inline] __run_hrtimer kernel/time/hrtimer.c:1898 [inline] __hrtimer_run_queues+0x2f0/0xa00 kernel/time/hrtimer.c:1994 hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2113 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] __sysvec_apic_timer_interrupt+0x10b/0x460 arch/x86/kernel/apic/apic.c:1067 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:percpu_down_read_internal include/linux/percpu-rwsem.h:72 [inline] RIP: 0010:percpu_down_read include/linux/percpu-rwsem.h:77 [inline] RIP: 0010:cpus_read_lock+0x8c/0x170 kernel/cpu.c:490 Code: 1a f4 41 00 8b 1d 34 0b a1 0c 31 ff 89 de e8 bb ee 41 00 85 db 0f 85 bd 00 00 00 e8 fe f3 41 00 48 8b 05 7f 0b a1 0c 65 ff 00 ef f3 41 00 bf 01 00 00 00 e8 95 f1 0d 00 65 8b 1d 0e 75 44 12 RSP: 0018:ffffc900031dfc90 EFLAGS: 00000203 RAX: ffffffff940b72e0 RBX: 0000000000000000 RCX: ffffc90007181000 RDX: 0000000000080000 RSI: ffffffff81c6bb02 RDI: ffff888059014a00 RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff9200063bfb6 R13: 1ffff9200063bf9f R14: 000000000d2b5132 R15: 0000000000000000 class_cpus_read_lock_constructor include/linux/cpuhplock.h:48 [inline] clock_was_set+0x96/0x870 kernel/time/hrtimer.c:988 do_settimeofday64+0x330/0x4d0 kernel/time/timekeeping.c:1603 do_sys_settimeofday64+0x1dc/0x260 kernel/time/time.c:195 __do_sys_clock_settime kernel/time/posix-timers.c:1124 [inline] __se_sys_clock_settime kernel/time/posix-timers.c:1108 [inline] __x64_sys_clock_settime+0x1c1/0x2a0 kernel/time/posix-timers.c:1108 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6ad699ce59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f6ad78be028 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3 RAX: ffffffffffffffda RBX: 00007f6ad6c16090 RCX: 00007f6ad699ce59 RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000000000000000 RBP: 00007f6ad6a32d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6ad6c16128 R14: 00007f6ad6c16090 R15: 00007ffccf5507c8