rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=c42c/1/0x4000000000000000 softirq=15654/15660 fqs=2 rcu: (detected by 1, t=10502 jiffies, g=11393, q=438 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 6928 Comm: syz.1.251 Not tainted 6.12.0-rc6-syzkaller-01362-ga58f00ed24b8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x81/0x90 kernel/kcov.c:316 Code: 8d 42 28 4c 39 c8 77 22 89 f8 89 f6 49 ff c2 4c 89 11 48 c7 44 0a 08 05 00 00 00 48 89 44 0a 10 48 89 74 0a 18 4c 89 44 0a 20 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 RSP: 0018:ffffc90000007d58 EFLAGS: 00000006 RAX: 0000000000010000 RBX: ffff8880b862c988 RCX: dffffc0000000000 RDX: ffff88806087da00 RSI: 0000000000000001 RDI: 0000000000000020 RBP: ffffc90000007ea8 R08: ffffffff81823497 R09: 1ffffffff203acfd R10: dffffc0000000000 R11: fffffbfff203acfe R12: 1ffff110170c593b R13: 0000000000000001 R14: ffff88802419d340 R15: ffff8880b862c880 FS: 00007febb22ff6c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000200003c0 CR3: 000000005d096000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __remove_hrtimer kernel/time/hrtimer.c:1119 [inline] __run_hrtimer kernel/time/hrtimer.c:1671 [inline] __hrtimer_run_queues+0x407/0xd50 kernel/time/hrtimer.c:1755 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1817 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:__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 2e 27 2b f6 f6 44 24 21 02 75 52 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 c3 b8 8f f5 65 8b 05 34 5e 30 74 85 c0 74 43 48 c7 04 24 0e 36 RSP: 0018:ffffc90004836e00 EFLAGS: 00000206 RAX: d925289a33db8c00 RBX: 1ffff92000906dc4 RCX: ffffffff8170bffa RDX: dffffc0000000000 RSI: ffffffff8c0acac0 RDI: 0000000000000001 RBP: ffffc90004836e90 R08: ffffffff942e095f R09: 1ffffffff285c12b R10: dffffc0000000000 R11: fffffbfff285c12c R12: dffffc0000000000 R13: 1ffff92000906dc0 R14: ffffc90004836e20 R15: 0000000000000246 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] taprio_change+0x351b/0x44f0 net/sched/sch_taprio.c:1973 taprio_init+0x9da/0xc80 net/sched/sch_taprio.c:2114 qdisc_create+0x9d4/0x11a0 net/sched/sch_api.c:1360 tc_modify_qdisc+0xa26/0x1e40 net/sched/sch_api.c:1782 rtnetlink_rcv_msg+0x73f/0xcf0 net/core/rtnetlink.c:6912 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2551 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline] netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1357 netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec net/socket.c:729 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:744 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2609 ___sys_sendmsg net/socket.c:2663 [inline] __sys_sendmsg+0x292/0x380 net/socket.c:2692 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: 0033:0x7febb157e719 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:00007febb22ff038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007febb1735f80 RCX: 00007febb157e719 RDX: 0000000000000000 RSI: 00000000200007c0 RDI: 0000000000000006 RBP: 00007febb15f1616 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007febb1735f80 R15: 00007ffff2b4b4c8 rcu: rcu_preempt kthread starved for 10494 jiffies! g11393 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:24912 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x184f/0x4c30 kernel/sched/core.c:6690 __schedule_loop kernel/sched/core.c:6767 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6782 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2615 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: 1 UID: 0 PID: 1089 Comm: kworker/u8:6 Not tainted 6.12.0-rc6-syzkaller-01362-ga58f00ed24b8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x1a04/0x2ca0 kernel/smp.c:884 Code: 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 31 ef 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 15 ef 0b 00 eb e4 44 89 e9 80 e1 07 80 c1 03 38 c1 7c e2 RSP: 0018:ffffc90003d376e0 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 1ffff110170c8c61 RCX: ffff888027038000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90003d378e0 R08: ffffffff8188eb1a R09: 1ffffffff285c100 R10: dffffc0000000000 R11: fffffbfff285c101 R12: dffffc0000000000 R13: ffff8880b8646308 R14: ffff8880b873fa80 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe292a656c0 CR3: 000000000e734000 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:1051 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2085 [inline] text_poke_bp_batch+0x352/0xb30 arch/x86/kernel/alternative.c:2295 text_poke_flush arch/x86/kernel/alternative.c:2486 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2493 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