rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P30779/1:b..l rcu: (detected by 0, t=10506 jiffies, g=229717, q=197 ncpus=2) task:syz.1.6479 state:R running task stack:26056 pid:30779 tgid:30776 ppid:25432 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7556 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x205/0xa00 kernel/entry/common.c:167 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:679 RIP: 0010:lock_acquire+0x5e/0x370 kernel/locking/lockdep.c:5872 Code: 05 bb ef 4e 12 83 f8 07 0f 87 da 00 00 00 48 0f a3 05 06 a2 16 0f 0f 82 ac 02 00 00 8b 35 ce d5 16 0f 85 f6 0f 85 c7 00 00 00 <48> 8b 44 24 30 65 48 2b 05 5d ef 4e 12 0f 85 ec 02 00 00 48 83 c4 RSP: 0018:ffffc90005906c38 EFLAGS: 00000206 RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8e137c0e RDI: ffffffff8c3e9b80 RBP: ffffffff8e9e60c0 R08: 000000000fc43284 R09: 0000000000000007 R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:840 [inline] class_rcu_constructor include/linux/rcupdate.h:1183 [inline] unwind_next_frame+0xd1/0x2090 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x162/0x1e0 mm/page_owner.c:165 __reset_page_owner+0x84/0x190 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] free_unref_folios+0xa44/0x1710 mm/page_alloc.c:3011 folios_put_refs+0x585/0xaa0 mm/swap.c:1057 free_pages_and_swap_cache+0x30b/0x3b0 mm/swap_state.c:589 __tlb_batch_free_encoded_pages+0xe9/0x280 mm/mmu_gather.c:138 tlb_batch_pages_flush mm/mmu_gather.c:151 [inline] tlb_flush_mmu_free mm/mmu_gather.c:417 [inline] tlb_flush_mmu mm/mmu_gather.c:424 [inline] tlb_finish_mmu+0x1b0/0x810 mm/mmu_gather.c:549 unmap_region+0x2d9/0x3b0 mm/vma.c:491 vms_clear_ptes mm/vma.c:1303 [inline] vms_clean_up_area mm/vma.c:1315 [inline] __mmap_setup mm/vma.c:2476 [inline] __mmap_region+0x1aec/0x2db0 mm/vma.c:2756 mmap_region+0x35d/0x620 mm/vma.c:2860 do_mmap+0xc63/0x12f0 mm/mmap.c:560 vm_mmap_pgoff+0x29e/0x470 mm/util.c:581 ksys_mmap_pgoff+0xe4/0x610 mm/mmap.c:606 __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+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7efc0f99ce59 RSP: 002b:00007efc10822028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007efc0fc16090 RCX: 00007efc0f99ce59 RDX: 000000000300000b RSI: 0000000000200000 RDI: 0000200000000000 RBP: 00007efc0fa32e6f R08: ffffffffffffffff R09: 00000000ec776000 R10: 0000000000204031 R11: 0000000000000246 R12: 0000000000000000 R13: 00007efc0fc16128 R14: 00007efc0fc16090 R15: 00007ffcf04fa9c8 rcu: rcu_preempt kthread timer wakeup didn't happen for 10505 jiffies! g229717 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=120285 rcu: rcu_preempt kthread starved for 10506 jiffies! g229717 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:28008 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7326 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2325 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: 30775 Comm: syz.5.6478 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:__kasan_check_byte+0x0/0x50 mm/kasan/common.c:572 Code: c9 5b 48 8d 74 15 00 5d ba fe 00 00 00 41 5c 41 5d e9 e4 2a 00 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <0f> 1f 40 d6 41 54 49 89 f4 55 48 89 fd 53 e8 7d 1e 00 00 89 c3 84 RSP: 0018:ffffc90000a08cd8 EFLAGS: 00000002 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8b9fc44a RDI: ffffffff9b6c4430 RBP: ffffffff9b6c4430 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f19b78a56c0(0000) GS:ffff8881241e0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000001ec00 CR3: 000000007e86f000 CR4: 00000000003526f0 DR0: 00000000000000d8 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: kasan_check_byte include/linux/kasan.h:402 [inline] lock_acquire kernel/locking/lockdep.c:5842 [inline] lock_acquire+0x132/0x370 kernel/locking/lockdep.c:5825 __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_activate+0x144/0x4b0 lib/debugobjects.c:873 debug_hrtimer_activate kernel/time/hrtimer.c:485 [inline] debug_activate kernel/time/hrtimer.c:528 [inline] enqueue_hrtimer+0x75/0x2f0 kernel/time/hrtimer.c:1109 __run_hrtimer kernel/time/hrtimer.c:2048 [inline] __hrtimer_run_queues+0x6ed/0x9c0 kernel/time/hrtimer.c:2096 hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2215 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline] __sysvec_apic_timer_interrupt+0x109/0x470 arch/x86/kernel/apic/apic.c:1068 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:its_return_thunk+0x0/0x10 arch/x86/lib/retpoline.S:417 Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 e9 0b 29 d5 f5 cc RSP: 0018:ffffc9000397fd00 EFLAGS: 00000283 RAX: 0000000000000120 RBX: 1ffff9200072ffa1 RCX: ffffc9001b177000 RDX: 0000000000080000 RSI: ffffffff858b13ce RDI: ffffc9000397fe90 RBP: 000005437efc129c R08: 0000000000000007 R09: 0000000000000000 R10: 000000001dfff6de R11: 0000000000000000 R12: ffffc9000397fe90 R13: 0000000000000010 R14: 000000000cf3f45e R15: 000000001d5ca29c add_device_randomness+0x7e/0x110 drivers/char/random.c:930 do_settimeofday64+0x3ef/0x4d0 kernel/time/timekeeping.c:1687 do_sys_settimeofday64+0x1dc/0x260 kernel/time/time.c:195 __do_sys_clock_settime kernel/time/posix-timers.c:1139 [inline] __se_sys_clock_settime kernel/time/posix-timers.c:1123 [inline] __x64_sys_clock_settime+0x1c1/0x2a0 kernel/time/posix-timers.c:1123 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f19b699ce59 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:00007f19b78a5028 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3 RAX: ffffffffffffffda RBX: 00007f19b6c15fa0 RCX: 00007f19b699ce59 RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000000000000000 RBP: 00007f19b6a32e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f19b6c16038 R14: 00007f19b6c15fa0 R15: 00007ffd678c1398