rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9/1:b..l (detected by 0, t=10502 jiffies, g=6285, q=47) task:kworker/u4:0 state:R running task stack:18008 pid: 9 ppid: 2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-8:0) Call Trace: context_switch kernel/sched/core.c:5029 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6375 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6551 preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6576 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] _raw_spin_unlock_irqrestore+0x128/0x130 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:418 [inline] __test_set_page_writeback+0x8ab/0xf10 mm/page-writeback.c:2881 ext4_bio_write_page+0x2b3/0x1f80 fs/ext4/page-io.c:-1 mpage_submit_page+0x18d/0x230 fs/ext4/inode.c:2112 mpage_map_and_submit_buffers fs/ext4/inode.c:2360 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2499 [inline] ext4_writepages+0x204f/0x3d10 fs/ext4/inode.c:2828 do_writepages+0x481/0x730 mm/page-writeback.c:2386 __writeback_single_inode+0x15b/0xe30 fs/fs-writeback.c:1647 writeback_sb_inodes+0xbce/0x1a40 fs/fs-writeback.c:1930 __writeback_inodes_wb+0x114/0x400 fs/fs-writeback.c:2001 wb_writeback+0x465/0xc50 fs/fs-writeback.c:2106 wb_check_old_data_flush fs/fs-writeback.c:2206 [inline] wb_do_writeback fs/fs-writeback.c:2259 [inline] wb_workfn+0xc55/0x1130 fs/fs-writeback.c:2288 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: rcu_preempt kthread starved for 10534 jiffies! g6285 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:25976 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5029 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6375 schedule+0x11b/0x1f0 kernel/sched/core.c:6458 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145 kthread+0x3f6/0x4f0 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4205 Comm: syz-executor111 Not tainted 5.15.179-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 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 ef d3 fe 02 66 2e 0f 1f 84 00 00 00 00 00 RSP: 0018:ffffc90000dd0e58 EFLAGS: 00000046 RAX: 00000000000057e7 RBX: ffffffff8c5ce9c8 RCX: 0000000000000838 RDX: 0000000000000000 RSI: 00000000000057e7 RDI: 0000000000000838 RBP: 00000000000057e7 R08: ffffffff8172a23d R09: fffffbfff1c153f6 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8880b8f27240 R13: dffffc0000000000 R14: 00000000000057e7 R15: dffffc0000000000 FS: 00005555942c5480(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000006b000 CR3: 0000000076d26000 CR4: 00000000003506e0 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_event+0x1c5/0x310 kernel/time/clockevents.c:334 hrtimer_interrupt+0x546/0x980 kernel/time/hrtimer.c:1827 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x13b/0x4b0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202 Code: 31 60 f6 ff 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 ce 67 19 f7 48 89 df e8 26 bc 1a f7 e8 11 7c 3d f7 fb bf 01 00 00 00 16 00 0e f7 65 8b 05 87 d0 b8 75 85 c0 74 02 5b c3 e8 54 ed b6 RSP: 0018:ffffc90002eefbc0 EFLAGS: 00000282 RAX: 93af68e10ee49c00 RBX: ffff88802a464a00 RCX: ffffffff96a95f03 RDX: dffffc0000000000 RSI: ffffffff8aab2a60 RDI: 0000000000000001 RBP: 0000000000000000 R08: ffffffff81871b70 R09: ffffed100548c941 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000021 R13: dffffc0000000000 R14: ffff88802a464e98 R15: ffff88802a464a00 spin_unlock_irq include/linux/spinlock.h:413 [inline] get_signal+0x13ee/0x14e0 kernel/signal.c:2903 arch_do_signal_or_restart+0xc3/0x1890 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x97/0x130 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+0x5d/0x240 kernel/entry/common.c:307 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fed64070a89 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 1b 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffcc4cac948 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007fed64070a89 RDX: 000020000006b000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 00007ffcc4cac97c R09: 00007ffcc4cac97c R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffcc4cac97c R13: 00007ffcc4cac9b0 R14: 00007ffcc4cac990 R15: 0000000000000003 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.169 msecs