rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=4854/1/0x4000000000000000 softirq=53148/53149 fqs=147 rcu: (detected by 0, t=10505 jiffies, g=58729, q=629 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 14051 Comm: syz.6.2347 Not tainted 6.13.0-rc3-syzkaller-00044-gaef25be35d23 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024 RIP: 0010:debug_object_activate+0x3e8/0x580 Code: 10 44 89 fe 41 ff d3 66 90 84 c0 74 2e ff 05 5f de 57 0b eb 24 42 0f b6 04 33 84 c0 0f 85 7b 01 00 00 41 c7 04 24 03 00 00 00 <48> 8b 7c 24 28 48 8b 74 24 20 e8 49 b6 02 07 31 db 48 c7 44 24 40 RSP: 0018:ffffc90000a18be0 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 1ffff1100d2b8e48 RCX: 0000000000000001 RDX: dffffc0000000000 RSI: 0000000000000004 RDI: ffffc90000a18ac0 RBP: ffffc90000a18cf8 R08: 0000000000000003 R09: fffff52000143158 R10: dffffc0000000000 R11: fffff52000143158 R12: ffff8880695c7240 R13: 1ffff92000143184 R14: dffffc0000000000 R15: ffff8880695c7230 FS: 00007f46dfff66c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2d914ff8 CR3: 0000000030efa000 CR4: 00000000003526f0 Call Trace: debug_hrtimer_activate kernel/time/hrtimer.c:428 [inline] debug_activate kernel/time/hrtimer.c:469 [inline] enqueue_hrtimer+0x30/0x3c0 kernel/time/hrtimer.c:1076 __run_hrtimer kernel/time/hrtimer.c:1756 [inline] __hrtimer_run_queues+0x6cb/0xd30 kernel/time/hrtimer.c:1803 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1865 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x110/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194 Code: 9c 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 1e f6 3f f6 f6 44 24 21 02 75 52 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 d3 26 aa f5 65 8b 05 44 79 40 74 85 c0 74 43 48 c7 04 24 0e 36 RSP: 0018:ffffc9000cdf7920 EFLAGS: 00000206 RAX: 802a7ee7f11dd800 RBX: 1ffff920019bef28 RCX: ffffffff817b270a RDX: dffffc0000000000 RSI: ffffffff8c0a9760 RDI: 0000000000000001 RBP: ffffc9000cdf79b0 R08: ffffffff94270887 R09: 1ffffffff284e110 R10: dffffc0000000000 R11: fffffbfff284e111 R12: dffffc0000000000 R13: 1ffff920019bef24 R14: ffffc9000cdf7940 R15: 0000000000000246 clock_was_set+0x686/0x810 kernel/time/hrtimer.c:959 timekeeping_inject_offset+0x3d2/0x520 kernel/time/timekeeping.c:1481 do_adjtimex+0x5b1/0xb10 kernel/time/timekeeping.c:2581 do_clock_adjtime kernel/time/posix-timers.c:1165 [inline] __do_sys_clock_adjtime kernel/time/posix-timers.c:1177 [inline] __se_sys_clock_adjtime kernel/time/posix-timers.c:1168 [inline] __x64_sys_clock_adjtime+0x1e1/0x290 kernel/time/posix-timers.c:1168 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: 0033:0x7f46e2185d29 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:00007f46dfff6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000131 RAX: ffffffffffffffda RBX: 00007f46e2375fa0 RCX: 00007f46e2185d29 RDX: 0000000000000000 RSI: 0000000020000480 RDI: 0000000000000000 RBP: 00007f46e2201a20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f46e2375fa0 R15: 00007fff54637968 rcu: rcu_preempt kthread starved for 9675 jiffies! g58729 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:25976 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x17fb/0x4be0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247 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: 0 UID: 0 PID: 10093 Comm: kworker/u8:16 Not tainted 6.13.0-rc3-syzkaller-00044-gaef25be35d23 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024 Workqueue: writeback wb_workfn (flush-8:0) RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x19f3/0x2c60 kernel/smp.c:884 Code: 45 8b 65 00 44 89 e6 83 e6 01 31 ff e8 56 e9 0b 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 01 e5 0b 00 eb 38 f3 90 <42> 0f b6 04 23 84 c0 75 11 41 f7 45 00 01 00 00 00 74 1e e8 e5 e4 RSP: 0018:ffffc9000c2adfc0 EFLAGS: 00000293 RAX: ffffffff81938ebb RBX: 1ffff110170e88b9 RCX: ffff88802adabc00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000c2ae1c0 R08: ffffffff81938e8a R09: 1ffff92001855be8 R10: dffffc0000000000 R11: ffffffff814d61f0 R12: dffffc0000000000 R13: ffff8880b87445c8 R14: ffff8880b863f940 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555793d65c8 CR3: 000000006042e000 CR4: 00000000003526f0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1051 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:939 [inline] flush_tlb_mm_range+0x329/0x5c0 arch/x86/mm/tlb.c:1025 flush_tlb_page arch/x86/include/asm/tlbflush.h:254 [inline] ptep_clear_flush+0x11a/0x170 mm/pgtable-generic.c:101 page_vma_mkclean_one+0x58a/0x9a0 mm/rmap.c:1051 page_mkclean_one+0x272/0x350 mm/rmap.c:1092 rmap_walk_file+0x502/0x780 mm/rmap.c:2708 rmap_walk mm/rmap.c:2726 [inline] folio_mkclean+0x252/0x370 mm/rmap.c:1124 folio_clear_dirty_for_io+0x219/0x950 mm/page-writeback.c:3033 mpage_submit_folio+0x84/0x340 fs/ext4/inode.c:1913 mpage_process_page_bufs+0x6d1/0x9d0 fs/ext4/inode.c:2045 mpage_prepare_extent_to_map+0xecb/0x1860 fs/ext4/inode.c:2546 ext4_do_writepages+0xc2a/0x3df0 fs/ext4/inode.c:2688 ext4_writepages+0x213/0x3c0 fs/ext4/inode.c:2824 do_writepages+0x35f/0x880 mm/page-writeback.c:2702 __writeback_single_inode+0x14f/0x10d0 fs/fs-writeback.c:1680 writeback_sb_inodes+0x820/0x1360 fs/fs-writeback.c:1976 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:2047 wb_writeback+0x427/0xb80 fs/fs-writeback.c:2158 wb_check_old_data_flush fs/fs-writeback.c:2262 [inline] wb_do_writeback fs/fs-writeback.c:2315 [inline] wb_workfn+0xb94/0x1080 fs/fs-writeback.c:2343 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 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