rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=f59/1/0x4000000000000000 softirq=11329/11330 fqs=1519 (detected by 1, t=10502 jiffies, g=14433, q=1760) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4599 Comm: syz.0.172 Not tainted 5.15.167-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:331 [inline] RIP: 0010:rcu_is_watching+0xc/0xa0 kernel/rcu/tree.c:1123 Code: 5a 34 c9 08 41 f7 c4 00 02 00 00 75 b4 eb b3 e8 3a 34 c9 08 66 2e 0f 1f 84 00 00 00 00 00 41 57 41 56 53 65 ff 05 8c 56 97 7e df 47 c9 08 89 c3 83 f8 08 73 72 49 bf 00 00 00 00 00 fc ff df RSP: 0018:ffffc90000007ca0 EFLAGS: 00000082 RAX: 0000000000010000 RBX: 0000000000000001 RCX: ffff88801ddf1dc0 RDX: ffff88801ddf1dc0 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffff88801eb60ae8 R08: ffffffff8881a2fe R09: fffffbfff20e2419 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88801eb60800 R13: ffff88801eb60b60 R14: dffffc0000000000 R15: 18001b5933eb6f99 FS: 00007fa735e506c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa735e4ff98 CR3: 0000000067f9f000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_lock include/linux/rcupdate.h:740 [inline] advance_sched+0x6e7/0x940 net/sched/sch_taprio.c:769 __run_hrtimer kernel/time/hrtimer.c:1688 [inline] __hrtimer_run_queues+0x598/0xcf0 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline] __sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xd4/0x130 kernel/locking/spinlock.c:194 Code: 9c 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 f2 3e 8c f7 f6 44 24 21 02 75 4e 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 87 87 19 f7 65 8b 05 08 8a c4 75 85 c0 74 3f 48 c7 04 24 0e 36 RSP: 0018:ffffc900035d7b60 EFLAGS: 00000206 RAX: 9cb7781236d09800 RBX: 1ffff920006baf70 RCX: ffffffff81631ae8 RDX: dffffc0000000000 RSI: ffffffff8a8b2b00 RDI: 0000000000000001 RBP: ffffc900035d7bf0 R08: dffffc0000000000 R09: fffffbfff20e2419 R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: 1ffff920006baf6c R14: ffffc900035d7b80 R15: 0000000000000246 clock_was_set+0x67d/0x880 kernel/time/hrtimer.c:970 do_settimeofday64+0x673/0x7e0 kernel/time/timekeeping.c:1328 __do_sys_clock_settime kernel/time/posix-timers.c:1124 [inline] __se_sys_clock_settime kernel/time/posix-timers.c:1112 [inline] __x64_sys_clock_settime+0x232/0x270 kernel/time/posix-timers.c:1112 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fa7379f8f39 Code: 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 01 48 RSP: 002b:00007fa735e50038 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3 RAX: ffffffffffffffda RBX: 00007fa737bb1058 RCX: 00007fa7379f8f39 RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000000 RBP: 00007fa737a6b216 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007fa737bb1058 R15: 00007ffc01cd59e8 rcu: rcu_preempt kthread starved for 7459 jiffies! g14433 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:26816 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 schedule+0x11b/0x1f0 kernel/sched/core.c:6456 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: NMI backtrace for cpu 1 CPU: 1 PID: 3637 Comm: kworker/u4:6 Not tainted 5.15.167-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: writeback wb_workfn (flush-8:0) Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline] rcu_check_gp_kthread_starvation+0x1d2/0x240 kernel/rcu/tree_stall.h:487 print_other_cpu_stall+0x137a/0x14d0 kernel/rcu/tree_stall.h:592 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline] rcu_pending kernel/rcu/tree.c:3932 [inline] rcu_sched_clock_irq+0xa38/0x1150 kernel/rcu/tree.c:2619 update_process_times+0x196/0x200 kernel/time/timer.c:1818 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1688 [inline] __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline] __sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:csd_lock_wait kernel/smp.c:440 [inline] RIP: 0010:smp_call_function_many_cond+0xaa1/0xd90 kernel/smp.c:969 Code: 44 89 fe 83 e6 01 31 ff e8 8c cc 0b 00 41 83 e7 01 75 07 e8 21 c9 0b 00 eb 41 f3 90 48 b8 00 00 00 00 00 fc ff df 0f b6 04 03 <84> c0 75 11 41 f7 45 00 01 00 00 00 74 1e e8 fc c8 0b 00 eb db 44 RSP: 0018:ffffc90003166500 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 1ffff11017208541 RCX: ffff88802985bb80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90003166640 R08: ffffffff81749144 R09: ffffed1017207679 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000 R13: ffff8880b9042a08 R14: ffff8880b913b380 R15: 0000000000000001 on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1135 __flush_tlb_multi arch/x86/include/asm/paravirt.h:87 [inline] flush_tlb_multi arch/x86/mm/tlb.c:900 [inline] flush_tlb_mm_range+0x2a5/0x4a0 arch/x86/mm/tlb.c:986 flush_tlb_page arch/x86/include/asm/tlbflush.h:239 [inline] ptep_clear_flush+0x112/0x150 mm/pgtable-generic.c:97 page_mkclean_one+0x428/0x7b0 mm/rmap.c:938 rmap_walk_file+0x3f8/0x600 mm/rmap.c:2378 rmap_walk mm/rmap.c:2396 [inline] page_mkclean+0x330/0x490 mm/rmap.c:1006 clear_page_dirty_for_io+0x3ce/0xa60 mm/page-writeback.c:2749 mpage_submit_page+0x90/0x230 fs/ext4/inode.c:2092 mpage_process_page_bufs+0x6c8/0x8b0 fs/ext4/inode.c:2226 mpage_prepare_extent_to_map+0xc9d/0x1150 fs/ext4/inode.c:2654 ext4_writepages+0xcd0/0x3d10 fs/ext4/inode.c:2782 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