rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=ea54/1/0x4000000000000000 softirq=57731/57732 fqs=2 rcu: (detected by 0, t=10505 jiffies, g=78677, q=220 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 13870 Comm: syz-executor.0 Not tainted 6.9.0-rc5-syzkaller-00329-g5d12ed4bea43 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:200 Code: 89 fb e8 23 00 00 00 48 8b 3d dc b3 3d 0c 48 89 de 5b e9 c3 d0 55 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 80 d3 03 00 65 8b 15 80 d5 RSP: 0018:ffffc90000a08d58 EFLAGS: 00000046 RAX: 0000000080010000 RBX: 0000000000000000 RCX: dffffc0000000000 RDX: ffff88802eca5a00 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000a08ea8 R08: ffffffff81838029 R09: 1ffffffff1f4f995 R10: dffffc0000000000 R11: fffffbfff1f4f996 R12: 1ffff110172a593b R13: ffffffff898185a0 R14: ffff888078318340 R15: 0000000000000001 FS: 000055557fc63480(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f684b7025e0 CR3: 000000005da90000 CR4: 00000000003506f0 Call Trace: __run_hrtimer kernel/time/hrtimer.c:1690 [inline] __hrtimer_run_queues+0x567/0xd50 kernel/time/hrtimer.c:1756 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1818 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline] __sysvec_apic_timer_interrupt+0x110/0x3f0 arch/x86/kernel/apic/apic.c:1049 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5758 Code: 2b 00 74 08 4c 89 f7 e8 ba d1 84 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:ffffc90011267ca0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff9200224cfa0 RCX: 0000000000000001 RDX: dffffc0000000000 RSI: ffffffff8bcaca20 RDI: ffffffff8c1eaaa0 RBP: ffffc90011267e00 R08: ffffffff92efe517 R09: 1ffffffff25dfca2 R10: dffffc0000000000 R11: fffffbfff25dfca3 R12: 1ffff9200224cf9c R13: dffffc0000000000 R14: ffffc90011267d00 R15: 0000000000000246 __fs_reclaim_acquire mm/page_alloc.c:3698 [inline] fs_reclaim_acquire+0x88/0x140 mm/page_alloc.c:3712 might_alloc include/linux/sched/mm.h:312 [inline] slab_pre_alloc_hook mm/slub.c:3746 [inline] slab_alloc_node mm/slub.c:3827 [inline] kmem_cache_alloc+0x48/0x340 mm/slub.c:3852 getname_flags+0xbd/0x4f0 fs/namei.c:139 getname fs/namei.c:218 [inline] __do_sys_symlinkat fs/namei.c:4523 [inline] __se_sys_symlinkat fs/namei.c:4520 [inline] __x64_sys_symlinkat+0x8b/0xb0 fs/namei.c:4520 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f684b67d627 Code: 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 0a 01 00 00 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:00007ffdab33d668 EFLAGS: 00000206 ORIG_RAX: 000000000000010a RAX: ffffffffffffffda RBX: 00007ffdab33d730 RCX: 00007f684b67d627 RDX: 00007f684b6ca545 RSI: 00000000ffffff9c RDI: 00007f684b6c950e RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000001 rcu: rcu_preempt kthread starved for 10495 jiffies! g78677 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:24560 pid:16 tgid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0x1796/0x4a00 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6838 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2582 rcu_gp_fqs_loop+0x2df/0x1370 kernel/rcu/tree.c:1663 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:1862 kthread+0x2f0/0x390 kernel/kthread.c:388 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 PID: 60 Comm: kworker/u8:4 Not tainted 6.9.0-rc5-syzkaller-00329-g5d12ed4bea43 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline] RIP: 0010:smp_call_function_many_cond+0x1894/0x2a00 kernel/smp.c:855 Code: 45 8b 65 00 44 89 e6 83 e6 01 31 ff e8 15 db 0b 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 c0 d6 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 a4 d6 RSP: 0018:ffffc900015b76e0 EFLAGS: 00000293 RAX: ffffffff818a274c RBX: 1ffff110172a8861 RCX: ffff8880173a3c00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900015b78e0 R08: ffffffff818a271b R09: 1ffffffff25dfca0 R10: dffffc0000000000 R11: fffffbfff25dfca1 R12: dffffc0000000000 R13: ffff8880b9544308 R14: ffff8880b943f780 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007efc221ff000 CR3: 000000000e134000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1023 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2086 [inline] text_poke_bp_batch+0x352/0xb30 arch/x86/kernel/alternative.c:2296 text_poke_flush arch/x86/kernel/alternative.c:2487 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2494 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x136/0x260 kernel/jump_label.c:205 static_key_enable+0x1a/0x20 kernel/jump_label.c:218 toggle_allocation_gate+0xb5/0x250 mm/kfence/core.c:826 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0xa10/0x17c0 kernel/workqueue.c:3335 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244