rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3560/1:b..l (detected by 1, t=10502 jiffies, g=10349, q=77) task:udevd state:R running task stack:25416 pid: 3560 ppid: 1 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6780 irqentry_exit+0x63/0x70 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:__legitimize_mnt+0x57/0x120 fs/namespace.c:589 Code: bc 00 00 00 00 00 fc ff df 49 8d 5e 30 49 89 dd 49 c1 ed 03 43 80 7c 25 00 00 74 08 48 89 df e8 7f a7 ed ff 48 8b 03 65 ff 00 83 44 24 fc 00 44 8b 3d 0c c7 12 0a 44 89 ff 89 ee e8 82 45 a9 RSP: 0018:ffffc90002ebf7c0 EFLAGS: 00000202 RAX: 0000607f46c253c8 RBX: ffff888143bc4f50 RCX: ffff88807cffbb80 RDX: 0000000000000000 RSI: 0000000000002868 RDI: 0000000000002868 RBP: 0000000000002868 R08: dffffc0000000000 R09: fffff520005d7f8a R10: fffff520005d7f8a R11: 1ffff920005d7f88 R12: dffffc0000000000 R13: 1ffff110287789ea R14: ffff888143bc4f20 R15: dffffc0000000000 __legitimize_path fs/namei.c:693 [inline] legitimize_path fs/namei.c:710 [inline] try_to_unlazy+0x108/0x6d0 fs/namei.c:779 may_lookup fs/namei.c:1690 [inline] link_path_walk+0x294/0xd40 fs/namei.c:2245 path_openat+0x27d/0x2f30 fs/namei.c:3738 do_filp_open+0x1b3/0x3e0 fs/namei.c:3769 do_sys_openat2+0x142/0x4a0 fs/open.c:1253 do_sys_open fs/open.c:1269 [inline] __do_sys_openat fs/open.c:1285 [inline] __se_sys_openat fs/open.c:1280 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1280 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f21867af407 RSP: 002b:00007ffe99859940 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f21866c1880 RCX: 00007f21867af407 RDX: 0000000000080241 RSI: 00007ffe99859db0 RDI: ffffffffffffff9c RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000000001b6 R11: 0000000000000202 R12: 00005650664b8dfc R13: 00005650664b8dfc R14: 0000000000000001 R15: 00007ffe99859ca0 rcu: rcu_preempt kthread starved for 10533 jiffies! g10349 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:27008 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376 schedule+0x11b/0x1e0 kernel/sched/core.c:6459 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5259 Comm: syz.1.60 Not tainted 5.15.189-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:27 [inline] RIP: 0010:static_key_false include/linux/jump_label.h:212 [inline] RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:156 [inline] RIP: 0010:wrmsr arch/x86/include/asm/msr.h:263 [inline] RIP: 0010:native_apic_msr_write+0x35/0x50 arch/x86/include/asm/apic.h:208 Code: 74 2a 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 <66> 90 c3 89 f6 31 d2 e9 3f 5c c7 02 66 2e 0f 1f 84 00 00 00 00 00 RSP: 0018:ffffc900037bf9d8 EFLAGS: 00000046 RAX: 000000000000003e RBX: 000000000000003e RCX: 0000000000000838 RDX: 0000000000000000 RSI: 000000000000003e RDI: 0000000000000838 RBP: 000000000000003e R08: dffffc0000000000 R09: fffffbfff1ad2dd6 R10: fffffbfff1ad2dd6 R11: 1ffffffff1ad2dd5 R12: ffff8880b9027280 R13: ffff8880b9027278 R14: ffffffff8bbbe9d8 R15: dffffc0000000000 FS: 00007ff15d05c6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000002006b000 CR3: 0000000057e5f000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: apic_write arch/x86/include/asm/apic.h:395 [inline] lapic_next_event+0x5b/0x70 arch/x86/kernel/apic/apic.c:468 clockevents_program_min_delta+0x1a9/0x340 kernel/time/clockevents.c:248 hrtimer_start_range_ns+0xa9a/0xc20 kernel/time/hrtimer.c:1292 posixtimer_rearm+0x131/0x340 kernel/time/posix-timers.c:329 dequeue_signal+0x174/0x440 kernel/signal.c:696 get_signal+0x6fe/0x12c0 kernel/signal.c:2781 arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7ff15ddde847 Code: ff ff 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 RSP: 002b:00007ff15d05c0e8 EFLAGS: 00000246 RAX: 00000000000000ca RBX: 00007ff15dfa3fa8 RCX: 00007ff15ddde849 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007ff15dfa3fa8 RBP: 00007ff15dfa3fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ff15dfa3fac R13: 0000000000000000 R14: 00007ffd49876380 R15: 00007ffd49876468 sched: RT throttling activated