rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5258/1:b..l P5349/1:b..l rcu: (detected by 1, t=10502 jiffies, g=9637, q=660 ncpus=2) task:udevd state:R running task stack:24256 pid:5349 tgid:5349 ppid:4548 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5248 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6600 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6922 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5820 Code: 2b 00 74 08 4c 89 f7 e8 aa e6 8a 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc90008cf7280 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff9200119ee5c RCX: 4ef7dedfc3390400 RDX: dffffc0000000000 RSI: ffffffff8bcada80 RDI: ffffffff8c207f20 RBP: ffffc90008cf73c8 R08: ffffffff93010787 R09: 1ffffffff26020f0 R10: dffffc0000000000 R11: fffffbfff26020f1 R12: 1ffff9200119ee58 R13: dffffc0000000000 R14: ffffc90008cf72e0 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:333 [inline] rcu_read_lock include/linux/rcupdate.h:845 [inline] __pte_offset_map+0x9e/0x380 mm/pgtable-generic.c:287 __pte_offset_map_lock+0xc7/0x300 mm/pgtable-generic.c:371 pte_offset_map_lock include/linux/mm.h:2986 [inline] zap_pte_range mm/memory.c:1597 [inline] zap_pmd_range mm/memory.c:1736 [inline] zap_pud_range mm/memory.c:1765 [inline] zap_p4d_range mm/memory.c:1786 [inline] unmap_page_range+0x95e/0x42c0 mm/memory.c:1807 unmap_vmas+0x3cc/0x5f0 mm/memory.c:1897 exit_mmap+0x264/0xc80 mm/mmap.c:3382 __mmput+0x115/0x390 kernel/fork.c:1347 exit_mm+0x220/0x310 kernel/exit.c:571 do_exit+0x9b2/0x27f0 kernel/exit.c:869 do_group_exit+0x207/0x2c0 kernel/exit.c:1031 __do_sys_exit_group kernel/exit.c:1042 [inline] __se_sys_exit_group kernel/exit.c:1040 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1040 x64_sys_call+0x26e0/0x26e0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6f37b86a90 RSP: 002b:00007fff6be052f8 EFLAGS: 00000206 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6f37b86a90 RDX: 00000000000000e7 RSI: 000000000000003c RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000007 R09: 13eccd003bf719a8 R10: 00000000ffffffff R11: 0000000000000206 R12: 0000558657d117d0 R13: 00007fff6be05338 R14: 0000000000000001 R15: 0000558657ce3910 task:udevd state:R running task stack:24256 pid:5258 tgid:5258 ppid:4548 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5248 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6600 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6779 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6803 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:1688 [inline] zap_pmd_range mm/memory.c:1736 [inline] zap_pud_range mm/memory.c:1765 [inline] zap_p4d_range mm/memory.c:1786 [inline] unmap_page_range+0x3818/0x42c0 mm/memory.c:1807 unmap_vmas+0x3cc/0x5f0 mm/memory.c:1897 exit_mmap+0x264/0xc80 mm/mmap.c:3382 __mmput+0x115/0x390 kernel/fork.c:1347 exit_mm+0x220/0x310 kernel/exit.c:571 do_exit+0x9b2/0x27f0 kernel/exit.c:869 do_group_exit+0x207/0x2c0 kernel/exit.c:1031 __do_sys_exit_group kernel/exit.c:1042 [inline] __se_sys_exit_group kernel/exit.c:1040 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1040 x64_sys_call+0x26e0/0x26e0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6f37b86a90 RSP: 002b:00007fff6be052f8 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6f37b86a90 RDX: 00000000000000e7 RSI: 000000000000003c RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000007 R09: 13eccd003bf719a8 R10: 00000000ffffffff R11: 0000000000000202 R12: 0000558657d02950 R13: 00007fff6be05338 R14: 0000000000000001 R15: 0000558657ce3910 rcu: rcu_preempt kthread starved for 10420 jiffies! g9637 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:24176 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5248 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6600 __schedule_loop kernel/sched/core.c:6677 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6692 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2034 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2236 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 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 6.10.0-rc6-next-20240703-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 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+0x21/0x30 drivers/acpi/processor_idle.c:113 Code: 90 90 90 90 90 90 90 90 90 65 48 8b 04 25 40 d7 03 00 48 f7 00 08 00 00 00 75 10 66 90 0f 00 2d 85 c7 98 00 f3 0f 1e fa fb f4 c3 cc cc cc cc 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 RSP: 0018:ffffc900001a7d08 EFLAGS: 00000246 RAX: ffff8880176f0000 RBX: ffff888018ab6864 RCX: 000000000006cc91 RDX: 0000000000000001 RSI: ffff888018ab6800 RDI: ffff888018ab6864 RBP: 000000000003a6b8 R08: ffff8880b9537c9b R09: 1ffff110172a6f93 R10: dffffc0000000000 R11: ffffffff8b915050 R12: ffff888017f67800 R13: 0000000000000000 R14: 0000000000000001 R15: ffffffff8ead8980 FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007feda4a59e97 CR3: 00000000685b6000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: acpi_idle_enter+0xe4/0x140 drivers/acpi/processor_idle.c:707 cpuidle_enter_state+0x112/0x480 drivers/cpuidle/cpuidle.c:267 cpuidle_enter+0x5d/0xa0 drivers/cpuidle/cpuidle.c:388 call_cpuidle kernel/sched/idle.c:155 [inline] cpuidle_idle_call kernel/sched/idle.c:230 [inline] do_idle+0x375/0x5d0 kernel/sched/idle.c:326 cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:424 start_secondary+0x100/0x100 arch/x86/kernel/smpboot.c:313 common_startup_64+0x13e/0x147