rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 ticks this GP) idle=1ab4/1/0x4000000000000000 softirq=48946/48946 fqs=1 rcu: (detected by 1, t=10502 jiffies, g=62361, q=474 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 9819 Comm: syz-executor.1 Not tainted 6.9.0-syzkaller-10323-g8f6a15f095a6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 RIP: 0010:__lock_acquire+0xc88/0x1fd0 kernel/locking/lockdep.c:5110 Code: bf 00 00 00 00 00 fc ff df 48 0f a3 1d 01 8d 88 11 0f 83 f6 08 00 00 49 8d 9d d0 0a 00 00 48 89 d8 48 c1 e8 03 48 89 44 24 38 <80> 3c 38 00 74 12 48 89 df e8 0a 81 89 00 48 bf 00 00 00 00 00 fc RSP: 0018:ffffc90000007910 EFLAGS: 00000806 RAX: 1ffff1100890bc9a RBX: ffff88804485e4d0 RCX: ffffffff8172886d RDX: 0000000000000000 RSI: 0000000000000008 RDI: dffffc0000000000 RBP: ffff88804485e558 R08: ffffffff92fb1587 R09: 1ffffffff25f62b0 R10: dffffc0000000000 R11: fffffbfff25f62b1 R12: 0000000000000001 R13: ffff88804485da00 R14: 1ffff1100890bcaf R15: ffff88804485e578 FS: 00007fb4fb7ef6c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f821000 CR3: 000000006e6dc000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __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_activate+0x16d/0x510 lib/debugobjects.c:708 debug_hrtimer_activate kernel/time/hrtimer.c:423 [inline] debug_activate kernel/time/hrtimer.c:478 [inline] enqueue_hrtimer+0x30/0x3c0 kernel/time/hrtimer.c:1085 __run_hrtimer kernel/time/hrtimer.c:1704 [inline] __hrtimer_run_queues+0x6d5/0xd50 kernel/time/hrtimer.c:1751 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1813 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:__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 8e 95 68 f6 f6 44 24 21 02 75 52 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 93 2f d2 f5 65 8b 05 c4 60 70 74 85 c0 74 43 48 c7 04 24 0e 36 RSP: 0018:ffffc90003876b40 EFLAGS: 00000206 RAX: 673c2680609e7b00 RBX: 1ffff9200070ed6c RCX: ffffffff8172e86a RDX: dffffc0000000000 RSI: ffffffff8bcab880 RDI: 0000000000000001 RBP: ffffc90003876bd0 R08: ffffffff92fb16e7 R09: 1ffffffff25f62dc R10: dffffc0000000000 R11: fffffbfff25f62dd R12: dffffc0000000000 R13: 1ffff9200070ed68 R14: ffffc90003876b60 R15: 0000000000000246 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] taprio_change+0x339b/0x42d0 net/sched/sch_taprio.c:1971 taprio_init+0x9da/0xc80 net/sched/sch_taprio.c:2112 qdisc_create+0x9d4/0x11a0 net/sched/sch_api.c:1355 tc_modify_qdisc+0xa26/0x1e40 net/sched/sch_api.c:1777 rtnetlink_rcv_msg+0x89b/0x10d0 net/core/rtnetlink.c:6595 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2564 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x8e1/0xcb0 net/netlink/af_netlink.c:1905 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2585 ___sys_sendmsg net/socket.c:2639 [inline] __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2668 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: 0033:0x7fb4faa7cee9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fb4fb7ef0c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fb4fababf80 RCX: 00007fb4faa7cee9 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000005 RBP: 00007fb4faac949e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fb4fababf80 R15: 00007fb4faccfa98 rcu: rcu_preempt kthread starved for 10500 jiffies! g62361 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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:25296 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0x17e8/0x4a50 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/0x1370 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: 1 PID: 11 Comm: kworker/u8:0 Not tainted 6.9.0-syzkaller-10323-g8f6a15f095a6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline] RIP: 0010:smp_call_function_many_cond+0x1899/0x2a00 kernel/smp.c:855 Code: 89 e6 83 e6 01 31 ff e8 95 0b 0c 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 40 07 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 24 07 0c 00 eb e4 44 RSP: 0018:ffffc900001076e0 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 1ffff11017288c11 RCX: ffff888016ec3c00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900001078e0 R08: ffffffff818a2a9b R09: 1ffffffff25f62b0 R10: dffffc0000000000 R11: fffffbfff25f62b1 R12: dffffc0000000000 R13: ffff8880b9446088 R14: ffff8880b953f900 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbf5411e108 CR3: 000000000e132000 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: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:3231 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd70 kernel/workqueue.c:3393 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