rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5194/1:b..l P5811/1:b..l rcu: (detected by 1, t=10502 jiffies, g=31217, q=149 ncpus=2) task:syz-executor state:R running task stack:25232 pid:5811 tgid:5811 ppid:5806 task_flags:0x40050c flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6765 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6944 preempt_schedule_thunk+0x1a/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:1772 [inline] zap_pmd_range mm/memory.c:1834 [inline] zap_pud_range mm/memory.c:1863 [inline] zap_p4d_range mm/memory.c:1884 [inline] unmap_page_range+0xee3/0x4390 mm/memory.c:1905 unmap_single_vma+0x194/0x2b0 mm/memory.c:1951 unmap_vmas+0x22f/0x490 mm/memory.c:1995 exit_mmap+0x1c1/0xba0 mm/mmap.c:1284 __mmput+0x12a/0x410 kernel/fork.c:1356 mmput+0x62/0x70 kernel/fork.c:1378 exit_mm kernel/exit.c:570 [inline] do_exit+0x9ba/0x2d70 kernel/exit.c:925 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087 get_signal+0x24ed/0x26c0 kernel/signal.c:3036 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f21a4983393 RSP: 002b:00007ffe47359b38 EFLAGS: 00000202 ORIG_RAX: 000000000000003d RAX: fffffffffffffe00 RBX: 00000000000016c0 RCX: 00007f21a4983393 RDX: 0000000040000000 RSI: 00007ffe47359b4c RDI: 00000000ffffffff RBP: 00007ffe47359b4c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000 task:udevd state:R running task stack:24240 pid:5194 tgid:5194 ppid:1 task_flags:0x400140 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6765 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7087 irqentry_exit+0x36/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x13/0x70 kernel/kcov.c:217 Code: 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 65 48 8b 15 44 f9 49 7e 65 8b 05 45 f9 49 7e 00 01 ff 00 48 8b 34 24 74 1d f6 c4 01 74 43 a9 00 00 0f 00 75 RSP: 0018:ffffc900041e7368 EFLAGS: 00000297 RAX: 0000000080000000 RBX: 00007f91a1efca12 RCX: ffffffff812bf4b5 RDX: ffff88802070c880 RSI: 0000000000000002 RDI: 0000000000000005 RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000002 R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000000 R13: ffffc900041e7490 R14: 0000000000000000 R15: ffff88802070c880 in_gate_area_no_mm+0x2f/0x70 arch/x86/entry/vsyscall/vsyscall_64.c:321 is_kernel_text include/linux/kallsyms.h:31 [inline] core_kernel_text kernel/extable.c:68 [inline] kernel_text_address+0x35/0x100 kernel/extable.c:99 __kernel_text_address+0xd/0x40 kernel/extable.c:79 unwind_get_return_address+0x59/0xa0 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0xa7/0x100 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122 save_stack+0x162/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x8d/0x400 mm/page_owner.c:297 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_frozen_pages+0x6db/0xfb0 mm/page_alloc.c:2660 __put_partials+0x14c/0x170 mm/slub.c:3153 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4e/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4115 [inline] kmem_cache_alloc_bulk_noprof+0x3e9/0xb10 mm/slub.c:5125 mt_alloc_bulk lib/maple_tree.c:181 [inline] mas_dup_alloc lib/maple_tree.c:6646 [inline] mas_dup_build.constprop.0+0xc6f/0x1760 lib/maple_tree.c:6710 __mt_dup+0xec/0x1f0 lib/maple_tree.c:6774 dup_mmap kernel/fork.c:660 [inline] dup_mm kernel/fork.c:1700 [inline] copy_mm kernel/fork.c:1752 [inline] copy_process+0x68f5/0x8c50 kernel/fork.c:2403 kernel_clone+0xfd/0x960 kernel/fork.c:2815 __do_sys_clone+0xcf/0x120 kernel/fork.c:2958 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f91a1efca12 RSP: 002b:00007ffcd12410e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000562052d9a301 RCX: 00007f91a1efca12 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 000000000000000b R08: 0000000000000000 R09: 0000562052d5a2c0 R10: 00007f91a2393550 R11: 0000000000000246 R12: 0000562052d67260 R13: 0000000000000000 R14: 0000000000000000 R15: 0000562052d5a2c0 rcu: rcu_preempt kthread starved for 10161 jiffies! g31217 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:28344 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6857 schedule_timeout+0x124/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2024 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2226 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.14.0-rc3-syzkaller-00295-g27102b38b8ca #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:92 [inline] RIP: 0010:acpi_safe_halt+0x1a/0x20 drivers/acpi/processor_idle.c:112 Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 65 48 8b 05 08 78 ac 74 48 8b 00 a8 08 75 0c 66 90 0f 00 2d 18 49 87 00 fb f4 c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc900001a7d58 EFLAGS: 00000246 RAX: 0000000000004000 RBX: 0000000000000001 RCX: ffffffff8b574469 RDX: 0000000000000001 RSI: ffff888020ad4000 RDI: ffff888020ad4064 RBP: ffff888020ad4064 R08: 0000000000000001 R09: ffffed10170e6f85 R10: ffff8880b8737c2b R11: 0000000000000000 R12: ffff88814769c800 R13: ffffffff8ee2dc60 R14: 0000000000000001 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff3d6ce800 CR3: 0000000061e12000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: acpi_idle_enter+0xc5/0x160 drivers/acpi/processor_idle.c:699 cpuidle_enter_state+0xaa/0x4f0 drivers/cpuidle/cpuidle.c:268 cpuidle_enter+0x4e/0xa0 drivers/cpuidle/cpuidle.c:389 cpuidle_idle_call kernel/sched/idle.c:230 [inline] do_idle+0x310/0x3f0 kernel/sched/idle.c:325 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423 start_secondary+0x222/0x2b0 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x148