rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (3 ticks this GP) idle=e3dc/1/0x4000000000000000 softirq=43621/43624 fqs=148 rcu: (detected by 0, t=10506 jiffies, g=34965, q=466 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 12990 Comm: syz.2.1596 Not tainted 6.13.0-rc7-syzkaller-00043-g619f0b6fad52 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:check_preemption_disabled+0x19/0x120 lib/smp_processor_id.c:14 Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 41 57 41 56 41 54 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 <65> 8b 1d 5c ac 42 74 65 8b 05 51 ac 42 74 a9 ff ff ff 7f 74 26 65 RSP: 0018:ffffc90000a189e8 EFLAGS: 00000086 RAX: a326cdf93c157400 RBX: ffffc90000a18a80 RCX: ffff88802efa46d8 RDX: dffffc0000000000 RSI: ffffffff8c0aaae0 RDI: ffffffff8c5edea0 RBP: ffffc90000a18b68 R08: ffffffff94271887 R09: 1ffffffff284e310 R10: dffffc0000000000 R11: fffffbfff284e311 R12: 1ffff9200014314c R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000046 FS: 00007f8fe1f436c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8fe11e3ce0 CR3: 000000006b4ba000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:467 [inline] lock_acquire+0x1fd/0x550 kernel/locking/lockdep.c:5851 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 debug_object_deactivate+0x158/0x390 lib/debugobjects.c:873 debug_hrtimer_deactivate kernel/time/hrtimer.c:433 [inline] debug_deactivate+0x1b/0x220 kernel/time/hrtimer.c:475 __run_hrtimer kernel/time/hrtimer.c:1707 [inline] __hrtimer_run_queues+0x305/0xd30 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 ae 83 3f f6 f6 44 24 21 02 75 52 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 43 b6 a9 f5 65 8b 05 84 07 40 74 85 c0 74 43 48 c7 04 24 0e 36 RSP: 0018:ffffc9000c65fba0 EFLAGS: 00000206 RAX: a326cdf93c157400 RBX: 1ffff920018cbf78 RCX: ffffffff817b282a RDX: dffffc0000000000 RSI: ffffffff8c0a98e0 RDI: 0000000000000001 RBP: ffffc9000c65fc30 R08: ffffffff94271887 R09: 1ffffffff284e310 R10: dffffc0000000000 R11: fffffbfff284e311 R12: dffffc0000000000 R13: 1ffff920018cbf74 R14: ffffc9000c65fbc0 R15: 0000000000000246 clock_was_set+0x686/0x810 kernel/time/hrtimer.c:959 do_settimeofday64+0x343/0x5e0 kernel/time/timekeeping.c:1442 __do_sys_clock_settime kernel/time/posix-timers.c:1135 [inline] __se_sys_clock_settime kernel/time/posix-timers.c:1119 [inline] __x64_sys_clock_settime+0x23a/0x280 kernel/time/posix-timers.c:1119 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: 0033:0x7f8fe1185d29 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:00007f8fe1f43038 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3 RAX: ffffffffffffffda RBX: 00007f8fe1375fa0 RCX: 00007f8fe1185d29 RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000000000000 RBP: 00007f8fe1201b08 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f8fe1375fa0 R15: 00007ffce7cf8fa8 rcu: rcu_preempt kthread starved for 9765 jiffies! g34965 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:26264 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: 292 Comm: kworker/u8:5 Not tainted 6.13.0-rc7-syzkaller-00043-g619f0b6fad52 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Workqueue: writeback wb_workfn (flush-8:0) RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x19f8/0x2c60 kernel/smp.c:884 Code: 89 e6 83 e6 01 31 ff e8 c6 e6 0b 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 71 e2 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 55 e2 0b 00 eb e4 44 RSP: 0018:ffffc90003095fc0 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 1ffff110170e88b9 RCX: ffff888022328000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900030961c0 R08: ffffffff81938f9a R09: 1ffff92000612be8 R10: dffffc0000000000 R11: ffffffff814d6230 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: 00005555943fc5c8 CR3: 0000000032188000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 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:3039 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:2708 __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:3236 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 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