rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 ticks this GP) idle=c8c4/1/0x4000000000000000 softirq=68968/68968 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P11126/1:b..l P12547/1:b..l rcu: (detected by 0, t=10506 jiffies, g=51357, q=302 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 12549 Comm: syz.0.1610 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__kasan_check_write+0x0/0x20 mm/kasan/shadow.c:36 Code: 0c 24 89 f6 31 d2 e9 5f f0 ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 0c 24 89 f6 ba 01 00 00 00 e9 2c f0 ff ff 66 66 RSP: 0018:ffffc90000a08cf0 EFLAGS: 00000046 RAX: 0000000000000001 RBX: ffff88805643a2a8 RCX: ffffffff819a554d RDX: ffffed100ac87456 RSI: 0000000000000004 RDI: ffffc90000a08d20 RBP: 1ffff920001411a0 R08: 0000000000000001 R09: ffffed100ac87455 R10: ffff88805643a2ab R11: ffff8880363bd4b0 R12: ffff88805643a2b0 R13: ffff88805643a2b8 R14: ffff88805643a300 R15: ffffffff898111e0 FS: 00007efd41ce66c0(0000) GS:ffff8881249f2000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c32a7ea CR3: 0000000033d39000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 000000000000e58e DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: instrument_read_write include/linux/instrumented.h:54 [inline] atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1301 [inline] queued_spin_lock include/asm-generic/qspinlock.h:111 [inline] do_raw_spin_lock+0x12c/0x2b0 kernel/locking/spinlock_debug.c:116 spin_lock include/linux/spinlock.h:351 [inline] advance_sched+0xd9/0xc80 net/sched/sch_taprio.c:930 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x202/0xc40 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x10b/0x3c0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__sanitizer_cov_trace_pc+0x56/0x70 kernel/kcov.c:222 Code: 00 f0 00 75 35 8b 82 6c 16 00 00 85 c0 74 2b 8b 82 48 16 00 00 83 f8 02 75 20 48 8b 8a 50 16 00 00 8b 92 4c 16 00 00 48 8b 01 <48> 83 c0 01 48 39 d0 73 07 48 89 01 48 89 34 c1 c3 cc cc cc cc 0f RSP: 0018:ffffc900032a76c0 EFLAGS: 00000246 RAX: 0000000000004a45 RBX: 0000000000000000 RCX: ffffc90004d42000 RDX: 0000000000080000 RSI: ffffffff8213a31b RDI: 0000000000000005 RBP: ffffea0000f61240 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: ffff8880363bd4b0 R12: 0000000000000000 R13: ffffea0000f61240 R14: 0000000000000000 R15: ffffea0000f61270 const_folio_flags+0x5b/0x100 include/linux/page-flags.h:353 folio_test_head include/linux/page-flags.h:844 [inline] folio_test_large include/linux/page-flags.h:865 [inline] __folio_add_rmap mm/rmap.c:1243 [inline] __folio_add_file_rmap mm/rmap.c:1585 [inline] folio_add_file_rmap_ptes+0x2cc/0xdb0 mm/rmap.c:1611 set_pte_range+0x2d7/0xa50 mm/memory.c:5481 finish_fault+0xa4f/0x13e0 mm/memory.c:5619 do_read_fault mm/memory.c:5759 [inline] do_fault+0xb0d/0x1ad0 mm/memory.c:5889 do_pte_missing mm/memory.c:4401 [inline] handle_pte_fault mm/memory.c:6273 [inline] __handle_mm_fault+0x1919/0x2bb0 mm/memory.c:6411 handle_mm_fault+0x3fe/0xad0 mm/memory.c:6580 faultin_page mm/gup.c:1126 [inline] __get_user_pages+0x54e/0x3590 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:3701 [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/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7efd40d8f749 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:00007efd41ce6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007efd40fe5fa0 RCX: 00007efd40d8f749 RDX: b635773f07ebbeeb RSI: 0000000000b36000 RDI: 0000200000000000 RBP: 00007efd40e13f91 R08: ffffffffffffffff R09: 00000000c36e5000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 00007efd40fe6038 R14: 00007efd40fe5fa0 R15: 00007fff43603c48 task:syz.1.1609 state:R running task stack:27544 pid:12547 tgid:12546 ppid:5816 task_flags:0x40054c flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:7047 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] zap_pte_range mm/memory.c:1884 [inline] zap_pmd_range mm/memory.c:1946 [inline] zap_pud_range mm/memory.c:1975 [inline] zap_p4d_range mm/memory.c:1996 [inline] unmap_page_range+0x1047/0x43c0 mm/memory.c:2017 unmap_single_vma+0x153/0x240 mm/memory.c:2059 unmap_vmas+0x218/0x470 mm/memory.c:2101 exit_mmap+0x1b0/0xb60 mm/mmap.c:1277 __mmput+0x12a/0x410 kernel/fork.c:1173 mmput+0x62/0x70 kernel/fork.c:1196 exit_mm kernel/exit.c:581 [inline] do_exit+0x7d7/0x2bd0 kernel/exit.c:959 do_group_exit+0xd3/0x2a0 kernel/exit.c:1112 get_signal+0x2671/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x7e0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x8c/0x540 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f63a958f749 RSP: 002b:00007f63aa4330e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f63a97e5fa8 RCX: 00007f63a958f749 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f63a97e5fa8 RBP: 00007f63a97e5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f63a97e6038 R14: 00007ffecd67b500 R15: 00007ffecd67b5e8 task:syz-executor state:R running task stack:23992 pid:11126 tgid:11126 ppid:11107 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:7047 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] copy_pte_range mm/memory.c:1331 [inline] copy_pmd_range mm/memory.c:1392 [inline] copy_pud_range mm/memory.c:1429 [inline] copy_p4d_range mm/memory.c:1453 [inline] copy_page_range+0x22d0/0x6780 mm/memory.c:1535 dup_mmap+0xbea/0x20e0 mm/mmap.c:1827 dup_mm kernel/fork.c:1529 [inline] copy_mm kernel/fork.c:1581 [inline] copy_process+0x3b9f/0x7430 kernel/fork.c:2221 kernel_clone+0xfc/0x910 kernel/fork.c:2651 __do_sys_clone+0xce/0x120 kernel/fork.c:2792 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff227d85e93 RSP: 002b:00007ffda52e5718 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff227d85e93 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 000055555f2147d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 00000000000880a1 R15: 00007ffda52e58b0 rcu: rcu_preempt kthread timer wakeup didn't happen for 10505 jiffies! g51357 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=37351 rcu: rcu_preempt kthread starved for 10506 jiffies! g51357 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:28440 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 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+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246