rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P17541/1:b..l P17455/1:b..l P12384/1:b..l rcu: (detected by 1, t=10502 jiffies, g=108133, q=276 ncpus=2) task:syz-executor state:R running task stack:21800 pid:12384 ppid:12367 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x15ae/0x4660 kernel/sched/core.c:6700 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6867 preempt_schedule+0xc0/0xd0 kernel/sched/core.c:6891 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3a/0x40 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] copy_pte_range mm/memory.c:1107 [inline] copy_pmd_range mm/memory.c:1168 [inline] copy_pud_range mm/memory.c:1205 [inline] copy_p4d_range mm/memory.c:1229 [inline] copy_page_range+0x2be5/0x3700 mm/memory.c:1323 dup_mmap kernel/fork.c:769 [inline] dup_mm kernel/fork.c:1694 [inline] copy_mm+0x1751/0x1e30 kernel/fork.c:1743 copy_process+0x171d/0x3df0 kernel/fork.c:2508 kernel_clone+0x24b/0x8a0 kernel/fork.c:2917 __do_sys_clone kernel/fork.c:3060 [inline] __se_sys_clone kernel/fork.c:3044 [inline] __x64_sys_clone+0x1b7/0x230 kernel/fork.c:3044 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fa3907c6912 RSP: 002b:00007ffdd87e9000 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffdd87e9000 RCX: 00007fa3907c6912 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffdd87e918c R08: 0000000000000000 R09: 0000000000000001 R10: 0000555589b337d0 R11: 0000000000000246 R12: 0000000000000001 R13: 000000000000005f R14: 00000000000f0677 R15: 00007ffdd87e91e0 task:syz.3.3567 state:R running task stack:23784 pid:17455 ppid:12384 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x15ae/0x4660 kernel/sched/core.c:6700 preempt_schedule_notrace+0xdd/0x110 kernel/sched/core.c:6960 preempt_schedule_notrace_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:46 rcu_lockdep_current_cpu_online+0x102/0x120 kernel/rcu/tree.c:4235 rcu_read_lock_held_common kernel/rcu/update.c:112 [inline] rcu_read_lock_held+0x1e/0x40 kernel/rcu/update.c:348 lookup_page_ext mm/page_ext.c:240 [inline] page_ext_get+0x193/0x2b0 mm/page_ext.c:509 __reset_page_owner+0x2e/0x190 mm/page_owner.c:145 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1182 [inline] free_unref_page_prepare+0x7d7/0x8f0 mm/page_alloc.c:2366 free_unref_page_list+0xbe/0x860 mm/page_alloc.c:2505 release_pages+0x208a/0x2300 mm/swap.c:1022 __folio_batch_release+0x71/0xe0 mm/swap.c:1042 folio_batch_release include/linux/pagevec.h:83 [inline] shmem_undo_range+0x5ff/0x1a80 mm/shmem.c:1026 shmem_truncate_range mm/shmem.c:1135 [inline] shmem_evict_inode+0x285/0xa70 mm/shmem.c:1264 evict+0x4b7/0x8a0 fs/inode.c:705 __dentry_kill+0x412/0x630 fs/dcache.c:611 dentry_kill+0xb8/0x290 fs/dcache.c:-1 dput+0xfe/0x1e0 fs/dcache.c:918 __fput+0x5b2/0x940 fs/file_table.c:426 task_work_run+0x1d4/0x260 kernel/task_work.c:245 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x986/0x2530 kernel/exit.c:884 do_group_exit+0x22d/0x2f0 kernel/exit.c:1026 get_signal+0x12a6/0x1390 kernel/signal.c:2903 arch_do_signal_or_restart+0xc2/0x7b0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x9/0x30 kernel/entry/common.c:315 exc_page_fault+0x8c/0x100 arch/x86/mm/fault.c:1519 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7fa390653b27 RSP: 002b:00007fa39160a120 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 000000000000000b RCX: 00007fa39079de99 RDX: 00007fa39160a140 RSI: 00007fa39160a270 RDI: 000000000000000b RBP: 00007fa390833eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fa390a26308 R14: 00007fa390a26270 R15: 00007ffdd87e8de8 task:syz.3.3590 state:R running task stack:23784 pid:17541 ppid:12384 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x15ae/0x4660 kernel/sched/core.c:6700 preempt_schedule_irq+0xbf/0x150 kernel/sched/core.c:7010 irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:get_stack_info_noinstr+0x6/0x130 arch/x86/kernel/dumpstack_64.c:172 Code: e8 0f ba c6 f6 5c 48 c7 c7 40 25 c5 8a e8 d2 40 00 00 65 c6 05 cc 9a 77 75 00 eb 9b cc cc cc cc cc cc cc cc 66 0f 1f 00 41 57 <41> 56 41 54 53 48 89 d3 49 89 f7 49 89 fe e8 17 01 00 00 89 c1 b0 RSP: 0018:ffffc900044dee80 EFLAGS: 00000282 RAX: ffffffff812fb0f9 RBX: ffffc900044def28 RCX: ffff88802a0f3c00 RDX: ffffc900044def28 RSI: ffff88802a0f3c00 RDI: ffffc900044deec8 RBP: ffffc900044def50 R08: ffffc900044def87 R09: 0000000000000000 R10: ffffc900044def28 R11: fffff5200089bdf1 R12: ffffc900044deec8 R13: ffffc900044def48 R14: ffffc900044def48 R15: ffff88802a0f3c00 get_stack_info+0x40/0x170 arch/x86/kernel/dumpstack_64.c:199 __unwind_start+0x406/0x730 arch/x86/kernel/unwind_orc.c:729 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xf8/0x190 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 save_stack+0x125/0x230 mm/page_owner.c:128 __reset_page_owner+0x4e/0x190 mm/page_owner.c:149 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1182 [inline] free_unref_page_prepare+0x7d7/0x8f0 mm/page_alloc.c:2366 free_unref_page_list+0xbe/0x860 mm/page_alloc.c:2505 release_pages+0x208a/0x2300 mm/swap.c:1022 __folio_batch_release+0x71/0xe0 mm/swap.c:1042 folio_batch_release include/linux/pagevec.h:83 [inline] shmem_undo_range+0x5ff/0x1a80 mm/shmem.c:1026 shmem_truncate_range mm/shmem.c:1135 [inline] shmem_evict_inode+0x285/0xa70 mm/shmem.c:1264 evict+0x4b7/0x8a0 fs/inode.c:705 __dentry_kill+0x412/0x630 fs/dcache.c:611 dentry_kill+0xb8/0x290 fs/dcache.c:-1 dput+0xfe/0x1e0 fs/dcache.c:918 __fput+0x5b2/0x940 fs/file_table.c:426 task_work_run+0x1d4/0x260 kernel/task_work.c:245 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x986/0x2530 kernel/exit.c:884 do_group_exit+0x22d/0x2f0 kernel/exit.c:1026 get_signal+0x12a6/0x1390 kernel/signal.c:2903 arch_do_signal_or_restart+0xc2/0x7b0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x9/0x30 kernel/entry/common.c:315 exc_page_fault+0x8c/0x100 arch/x86/mm/fault.c:1519 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7fa390653b27 RSP: 002b:00007fa39160a120 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 000000000000000b RCX: 00007fa39079de99 RDX: 00007fa39160a140 RSI: 00007fa39160a270 RDI: 000000000000000b RBP: 00007fa390833eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fa390a26308 R14: 00007fa390a26270 R15: 00007ffdd87e8de8 rcu: rcu_preempt kthread starved for 10555 jiffies! g108133 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:26224 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x15ae/0x4660 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x30d/0x1590 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:pv_native_safe_halt+0xf/0x10 arch/x86/kernel/paravirt.c:148 Code: cc 1c 02 c3 cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d c3 f7 3b 00 fb f4 66 0f 1f 00 55 41 57 41 56 41 54 53 50 8b 2f eb 2c 89 cb 80 f9 RSP: 0018:ffffc90000187de0 EFLAGS: 000002c6 RAX: 43e93639aebb9c00 RBX: ffffffff81630b01 RCX: 43e93639aebb9c00 RDX: 0000000000000001 RSI: ffffffff8acacbe0 RDI: ffffffff8b1cfaa0 RBP: ffffc90000187f20 R08: ffff8880b8f36bab R09: 1ffff110171e6d75 R10: dffffc0000000000 R11: ffffed10171e6d76 R12: 1ffff92000030fc8 R13: dffffc0000000000 R14: 1ffff110036ce780 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd05c3246c8 CR3: 000000002d639000 CR4: 00000000003506e0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:753 default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97 cpuidle_idle_call kernel/sched/idle.c:178 [inline] do_idle+0x221/0x5c0 kernel/sched/idle.c:302 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:401 start_secondary+0xee/0xf0 arch/x86/kernel/smpboot.c:323 secondary_startup_64_no_verify+0x179/0x17b