rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=2774/1/0x4000000000000000 softirq=60238/60247 fqs=6 rcu: (detected by 0, t=10502 jiffies, g=67401, q=364 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 17101 Comm: syz.4.2970 Not tainted 6.12.0-syzkaller-10553-gb86545e02e8c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:match_held_lock+0x1/0xb0 kernel/locking/lockdep.c:5294 Code: 83 c4 10 5b 41 5e 41 5f c3 cc cc cc cc e8 07 f9 ff ff 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 <53> bd 01 00 00 00 48 39 77 10 74 67 48 89 fb 81 7f 20 00 00 20 00 RSP: 0018:ffffc90000a18c18 EFLAGS: 00000097 RAX: 0000000000000001 RBX: ffff88802681e4e0 RCX: ffff88802681da00 RDX: ffff88802681da00 RSI: ffff888031cc9300 RDI: ffff88802681e4e0 RBP: 0000000000000000 R08: ffffffff89ccfdc1 R09: fffff5200014317c R10: dffffc0000000000 R11: fffff5200014317c R12: 0000000000000046 R13: ffff88802681da00 R14: 00000000ffffffff R15: ffff888031cc9300 FS: 00007f6096ce16c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000006cf44000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 00000000000000a1 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: __lock_is_held kernel/locking/lockdep.c:5590 [inline] lock_is_held_type+0xa9/0x190 kernel/locking/lockdep.c:5921 lock_is_held include/linux/lockdep.h:249 [inline] advance_sched+0x148/0xca0 net/sched/sch_taprio.c:927 __run_hrtimer kernel/time/hrtimer.c:1739 [inline] __hrtimer_run_queues+0x59b/0xd50 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:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5853 Code: 2b 00 74 08 4c 89 f7 e8 1a 84 8c 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc9001030f380 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff92002061e7c RCX: ffff88802681e4d8 RDX: dffffc0000000000 RSI: ffffffff8c0aeb60 RDI: ffffffff8c6083a0 RBP: ffffc9001030f4d8 R08: ffffffff942f0897 R09: 1ffffffff285e112 R10: dffffc0000000000 R11: fffffbfff285e113 R12: 1ffff92002061e78 R13: dffffc0000000000 R14: ffffc9001030f3e0 R15: 0000000000000246 __fs_reclaim_acquire mm/page_alloc.c:3851 [inline] fs_reclaim_acquire+0x88/0x130 mm/page_alloc.c:3865 might_alloc include/linux/sched/mm.h:318 [inline] prepare_alloc_pages+0x147/0x5b0 mm/page_alloc.c:4510 __alloc_pages_noprof+0x16f/0x710 mm/page_alloc.c:4740 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265 folio_alloc_mpol_noprof+0x36/0x50 mm/mempolicy.c:2283 shmem_alloc_folio mm/shmem.c:1794 [inline] shmem_alloc_and_add_folio+0x49b/0x13d0 mm/shmem.c:1833 shmem_get_folio_gfp+0x5a9/0x20a0 mm/shmem.c:2355 shmem_get_folio mm/shmem.c:2461 [inline] shmem_write_begin+0x17e/0x460 mm/shmem.c:3117 generic_perform_write+0x344/0x6d0 mm/filemap.c:4055 shmem_file_write_iter+0xf9/0x120 mm/shmem.c:3293 new_sync_write fs/read_write.c:586 [inline] vfs_write+0xaeb/0xd30 fs/read_write.c:679 ksys_write+0x18f/0x2b0 fs/read_write.c:731 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: 0033:0x7f6095f80809 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:00007f6096ce1058 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f6096145fa0 RCX: 00007f6095f80809 RDX: 000000000208e24b RSI: 0000000020000240 RDI: 0000000000000003 RBP: 00007f6095ff393e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f6096145fa0 R15: 00007fff3fa13c98 rcu: rcu_preempt kthread starved for 10490 jiffies! g67401 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:25624 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: 6461 Comm: kworker/u8:10 Not tainted 6.12.0-syzkaller-10553-gb86545e02e8c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x19f3/0x2ca0 kernel/smp.c:884 Code: 45 8b 65 00 44 89 e6 83 e6 01 31 ff e8 36 ea 0b 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 e1 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 c5 e5 RSP: 0018:ffffc900056976e0 EFLAGS: 00000293 RAX: ffffffff8189fe6b RBX: 1ffff110170e88b9 RCX: ffff88802d2f0000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900056978e0 R08: ffffffff8189fe3a R09: 1ffffffff285e110 R10: dffffc0000000000 R11: fffffbfff285e111 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: 0000001b316dac00 CR3: 000000000e738000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000016 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1051 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2114 [inline] text_poke_bp_batch+0x352/0xb30 arch/x86/kernel/alternative.c:2324 text_poke_flush arch/x86/kernel/alternative.c:2515 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2522 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x136/0x260 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xbc/0x260 mm/kfence/core.c:849 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 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