rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=4e54/1/0x4000000000000000 softirq=104516/104517 fqs=1 rcu: (detected by 0, t=10505 jiffies, g=154025, q=354 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 23766 Comm: syz.0.6629 Not tainted 6.10.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 RIP: 0010:rb_red_parent lib/rbtree.c:66 [inline] RIP: 0010:__rb_insert lib/rbtree.c:88 [inline] RIP: 0010:rb_insert_color+0x25/0x690 lib/rbtree.c:436 Code: 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 38 49 89 f7 48 89 fd 48 bb 00 00 00 00 00 fc ff df 48 89 f8 <48> c1 e8 03 80 3c 18 00 74 08 48 89 ef e8 a9 d9 82 f6 48 89 6c 24 RSP: 0018:ffffc90000a18c50 EFLAGS: 00000086 RAX: ffff88807e843340 RBX: dffffc0000000000 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: ffff8880b952c9d0 RDI: ffff88807e843340 RBP: ffff88807e843340 R08: ffff88807e843357 R09: 0000000000000000 R10: ffff88807e843340 R11: ffffed100fd0866b R12: ffff8880b952c9d0 R13: ffff8880b952c9d0 R14: 0000000000000000 R15: ffff8880b952c9d0 FS: 000055557e7bb500(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c28e29e CR3: 0000000063da8000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: rb_insert_color_cached include/linux/rbtree.h:114 [inline] rb_add_cached include/linux/rbtree.h:183 [inline] timerqueue_add+0x260/0x290 lib/timerqueue.c:40 enqueue_hrtimer+0x1b2/0x3c0 kernel/time/hrtimer.c:1093 __run_hrtimer kernel/time/hrtimer.c:1706 [inline] __hrtimer_run_queues+0x6cb/0xd50 kernel/time/hrtimer.c:1753 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1815 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_is_held_type+0x13b/0x190 Code: 75 44 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 4c 41 f7 c4 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 42 89 d8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f RSP: 0018:ffffc9000c8ff7b8 EFLAGS: 00000206 RAX: 99ef63be1f0e5a00 RBX: 0000000000000000 RCX: ffff888021b59e00 RDX: 0000000000000000 RSI: ffffffff8bcacca0 RDI: ffffffff8c1f16c0 RBP: ffffc9000c8ff9f0 R08: ffffc9000c8ff97f R09: 0000000000000000 R10: ffffc9000c8ff970 R11: fffff5200191ff30 R12: 0000000000000246 R13: ffff888021b59e00 R14: 00000000ffffffff R15: ffffffff8e333f80 lock_is_held include/linux/lockdep.h:231 [inline] schedule_debug kernel/sched/core.c:5981 [inline] __schedule+0x209/0x49d0 kernel/sched/core.c:6628 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6837 futex_wait_queue+0x14e/0x1d0 kernel/futex/waitwake.c:370 __futex_wait+0x17f/0x320 kernel/futex/waitwake.c:669 futex_wait+0x101/0x360 kernel/futex/waitwake.c:697 do_futex+0x33b/0x560 kernel/futex/syscalls.c:102 __do_sys_futex kernel/futex/syscalls.c:179 [inline] __se_sys_futex+0x3f9/0x480 kernel/futex/syscalls.c:160 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: 0033:0x7f562c775b99 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:00007ffc4b5a7da8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 000000000012e654 RCX: 00007f562c775b99 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f562c903fac RBP: 000000000012e622 R08: 7fffffffffffffff R09: 000000074b5a80bf R10: 00007ffc4b5a7e90 R11: 0000000000000246 R12: 00007f562c903fac R13: 0000000000000032 R14: 00007ffc4b5a7eb0 R15: 00007ffc4b5a7e90 rcu: rcu_preempt kthread starved for 10500 jiffies! g154025 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:25584 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0x1796/0x49d0 kernel/sched/core.c:6745 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6837 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2000 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2202 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 PID: 2449 Comm: kworker/u8:6 Not tainted 6.10.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline] RIP: 0010:smp_call_function_many_cond+0x1860/0x29d0 kernel/smp.c:855 Code: 45 8b 65 00 44 89 e6 83 e6 01 31 ff e8 c9 0c 0c 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 74 08 0c 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 58 08 RSP: 0018:ffffc900090a7700 EFLAGS: 00000293 RAX: ffffffff818a1e08 RBX: 1ffff110172a8891 RCX: ffff888029878000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900090a78e0 R08: ffffffff818a1dd7 R09: 1ffffffff25ee2b0 R10: dffffc0000000000 R11: fffffbfff25ee2b1 R12: dffffc0000000000 R13: ffff8880b9544488 R14: ffff8880b943f880 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007efd09549480 CR3: 000000000e132000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 000000000000000e DR6: 00000000ffff0ff0 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:2069 [inline] text_poke_bp_batch+0x352/0xb30 arch/x86/kernel/alternative.c:2279 text_poke_flush arch/x86/kernel/alternative.c:2470 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2477 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:3248 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3329 worker_thread+0x86d/0xd50 kernel/workqueue.c:3409 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