rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (0 ticks this GP) idle=5f7c/1/0x4000000000000000 softirq=79542/79542 fqs=3 rcu: (detected by 0, t=10502 jiffies, g=108233, q=278 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 17921 Comm: syz.2.3577 Not tainted 6.10.0-rc6-syzkaller-00067-g8a9c6c40432e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 RIP: 0010:rb_insert_color_cached include/linux/rbtree.h:113 [inline] RIP: 0010:rb_add_cached include/linux/rbtree.h:183 [inline] RIP: 0010:timerqueue_add+0x228/0x290 lib/timerqueue.c:40 Code: 7c f6 48 b8 00 00 00 00 00 fc ff df 80 3c 03 00 74 08 4c 89 e7 e8 e8 dd 7c f6 4d 89 3c 24 eb 0a e8 8d 27 17 f6 4c 8b 64 24 08 <49> 8d 5c 24 08 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df RSP: 0018:ffffc90000a18cc0 EFLAGS: 00000046 RAX: ffffffff8b7effc3 RBX: ffff888059db0340 RCX: ffff8880294e3c00 RDX: 0000000000010001 RSI: 0000000000000000 RDI: ffff888059db0358 RBP: ffffffff947e29e0 R08: ffff888059db0357 R09: ffff888059db0348 R10: dffffc0000000000 R11: ffffed100b3b606b R12: ffff8880b952c9d0 R13: 1ffffffff28fc53e R14: 0000000000000010 R15: ffff888059db0340 FS: 00007f6612c106c0(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c25b566 CR3: 000000005a02a000 CR4: 0000000000350ef0 Call Trace: 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+0x112/0x3f0 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:read_seqbegin+0x1d2/0x250 include/linux/seqlock.h:772 Code: 68 82 ff 4d 85 ed 75 16 e8 5b 68 82 ff eb 15 e8 54 68 82 ff e8 af 27 72 09 4d 85 ed 74 ea e8 45 68 82 ff fb 8b 1d 6e 87 ed 0b <89> de 83 e6 01 31 ff e8 72 6c 82 ff 89 d8 83 e0 01 75 07 e8 26 68 RSP: 0018:ffffc90004d87420 EFLAGS: 00000283 RAX: ffffffff8213bf0b RBX: 0000000000006086 RCX: 0000000000040000 RDX: ffffc9001362a000 RSI: 0000000000000903 RDI: 0000000000000904 RBP: ffffc90004d874d0 R08: ffffffff8213bee1 R09: 1ffffffff25f4ec3 R10: dffffc0000000000 R11: fffffbfff25f4ec4 R12: 1ffff920009b0e84 R13: 0000000000000200 R14: 0000000000000046 R15: dffffc0000000000 d_alloc_parallel+0x402/0x1600 fs/dcache.c:2472 __lookup_slow+0x117/0x3f0 fs/namei.c:1677 lookup_slow+0x53/0x70 fs/namei.c:1709 walk_component fs/namei.c:2004 [inline] link_path_walk+0x9ea/0xea0 fs/namei.c:2331 path_openat+0x257/0x35f0 fs/namei.c:3809 do_filp_open+0x235/0x490 fs/namei.c:3840 do_sys_openat2+0x13e/0x1d0 fs/open.c:1413 do_sys_open fs/open.c:1428 [inline] __do_sys_openat fs/open.c:1444 [inline] __se_sys_openat fs/open.c:1439 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1439 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: 0033:0x7f6611d74610 Code: 48 89 44 24 20 75 93 44 89 54 24 0c e8 79 8d 02 00 44 8b 54 24 0c 89 da 48 89 ee 41 89 c0 bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 38 44 89 c7 89 44 24 0c e8 cc 8d 02 00 8b 44 RSP: 002b:00007f6612c0ff70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6611d74610 RDX: 0000000000000000 RSI: 00007f6611de3609 RDI: 00000000ffffff9c RBP: 00007f6611de3609 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 000000000000000b R14: 00007f6611f03f60 R15: 00007fff8a556e08 rcu: rcu_preempt kthread starved for 10496 jiffies! g108233 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+0x17e8/0x4a20 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+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/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: 6020 Comm: kworker/u8:11 Not tainted 6.10.0-rc6-syzkaller-00067-g8a9c6c40432e #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+0x1865/0x29d0 kernel/smp.c:855 Code: 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 0c 00 eb e4 44 RSP: 0018:ffffc90016267700 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 1ffff110172a8899 RCX: ffff88802f1d9e00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900162678e0 R08: ffffffff818a1ec7 R09: 1ffffffff25f4eb0 R10: dffffc0000000000 R11: fffffbfff25f4eb1 R12: dffffc0000000000 R13: ffff8880b95444c8 R14: ffff8880b943f8c0 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555584448808 CR3: 000000000e132000 CR4: 0000000000350ef0 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+0xa2e/0x1830 kernel/workqueue.c:3329 worker_thread+0x86d/0xd50 kernel/workqueue.c:3409 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244