rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4676/1:b..l rcu: (detected by 0, t=10502 jiffies, g=11149, q=683 ncpus=2) task:udevd state:R running task stack:23552 pid:4676 tgid:4676 ppid:1 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6529 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6851 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:5763 Code: 2b 00 74 08 4c 89 f7 e8 8a 00 8b 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:ffffc90004a076c0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff92000940ee4 RCX: 2f602a6afc9b6700 RDX: dffffc0000000000 RSI: ffffffff8c0ae6e0 RDI: ffffffff8c606400 RBP: ffffc90004a07808 R08: ffffffff9372e847 R09: 1ffffffff26e5d08 R10: dffffc0000000000 R11: fffffbfff26e5d09 R12: 1ffff92000940ee0 R13: dffffc0000000000 R14: ffffc90004a07720 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:326 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] dput+0x54/0x2b0 fs/dcache.c:845 step_into+0x355/0x1080 fs/namei.c:1892 lookup_last fs/namei.c:2542 [inline] path_lookupat+0x16f/0x450 fs/namei.c:2566 filename_lookup+0x256/0x610 fs/namei.c:2595 vfs_statx+0x103/0x490 fs/stat.c:312 vfs_fstatat+0x145/0x190 fs/stat.c:341 __do_sys_newfstatat fs/stat.c:505 [inline] __se_sys_newfstatat fs/stat.c:499 [inline] __x64_sys_newfstatat+0x11d/0x1a0 fs/stat.c:499 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: 0033:0x7fb891d165f4 RSP: 002b:00007ffc0d6d3918 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 00007ffc0d6d52b8 RCX: 00007fb891d165f4 RDX: 00007ffc0d6d3928 RSI: 00007ffc0d6d3db8 RDI: 00000000ffffff9c RBP: 00007ffc0d6d39b8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc0d6d3db8 R13: 00007ffc0d6d3928 R14: 000055efaccf8910 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10543 jiffies! g11149 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 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:26640 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6621 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+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/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: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.11.0-rc3-syzkaller-00007-gd74da846046a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 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:112 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 eb 07 0f 00 2d e5 d6 b3 00 f3 0f 1e fa fb f4 e9 24 00 3a 00 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 RSP: 0018:ffffffff8e607ca8 EFLAGS: 00000246 RAX: ffffffff8e694680 RBX: ffff88801d6c0064 RCX: 000000000008d9f9 RDX: 0000000000000001 RSI: ffff88801d6c0000 RDI: ffff88801d6c0064 RBP: 000000000003a6b8 R08: ffff8880b9237c7b R09: 1ffff11017246f8f R10: dffffc0000000000 R11: ffffffff8bb63c90 R12: ffff88801af16800 R13: 0000000000000000 R14: 0000000000000001 R15: ffffffff8f0dcf00 FS: 0000000000000000(0000) GS:ffff8880b9200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000000573e2000 CR4: 0000000000350ef0 Call Trace: acpi_idle_enter+0xe4/0x140 drivers/acpi/processor_idle.c:702 cpuidle_enter_state+0x114/0x480 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 rest_init+0x2dc/0x300 init/main.c:747 start_kernel+0x47a/0x500 init/main.c:1103 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:507 x86_64_start_kernel+0x9f/0xa0 arch/x86/kernel/head64.c:488 common_startup_64+0x13e/0x147