rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=12bc/1/0x4000000000000000 softirq=23205/23206 fqs=1 (detected by 1, t=10505 jiffies, g=27953, q=126 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 7087 Comm: syz.2.784 Not tainted 6.1.147-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:__lock_release kernel/locking/lockdep.c:5316 [inline] RIP: 0010:lock_release+0x176/0x910 kernel/locking/lockdep.c:5682 Code: 00 9c 8f 84 24 a0 00 00 00 48 8b 84 24 a0 00 00 00 48 89 44 24 50 fa 48 c7 c7 40 11 8c 8a e8 01 cb b2 08 65 ff 05 ba 0c 9f 7e 44 24 5c 01 00 00 00 48 c7 c0 64 80 1f 8e 48 c1 e8 03 42 0f b6 RSP: 0018:ffffc90000007b60 EFLAGS: 00000002 RAX: 0000000000000000 RBX: ffff88807beda89c RCX: 6e8216eb2c6a0700 RDX: 0000000000000000 RSI: ffffffff8a8c1140 RDI: ffffffff8adef320 RBP: ffffc90000007c70 R08: dffffc0000000000 R09: fffffbfff1c3e976 R10: fffffbfff1c3e976 R11: 1ffffffff1c3e975 R12: dffffc0000000000 R13: dffffc0000000000 R14: ffff88807bed9dc0 R15: 1ffff92000000f78 FS: 00007fdee3a436c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000007b8b5000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline] _raw_spin_unlock_irqrestore+0x6d/0x100 kernel/locking/spinlock.c:194 __run_hrtimer kernel/time/hrtimer.c:1748 [inline] __hrtimer_run_queues+0x446/0xd60 kernel/time/hrtimer.c:1816 hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1878 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline] __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa5/0x100 kernel/locking/spinlock.c:194 Code: 74 05 e8 2e e9 66 f7 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 b6 74 37 f7 65 8b 05 87 35 e2 75 85 c0 74 3c 48 c7 04 24 0e 36 RSP: 0018:ffffc90003b3ed20 EFLAGS: 00000206 RAX: 6e8216eb2c6a0700 RBX: 0000000000000a02 RCX: 6e8216eb2c6a0700 RDX: dffffc0000000000 RSI: ffffffff8a8c0460 RDI: 0000000000000001 RBP: ffffc90003b3edb0 R08: dffffc0000000000 R09: fffffbfff215ba76 R10: fffffbfff215ba76 R11: 1ffffffff215ba75 R12: dffffc0000000000 R13: 0000000000000a02 R14: ffff888053c602e8 R15: 1ffff92000767da4 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] taprio_change+0x4143/0x50f0 net/sched/sch_taprio.c:1689 qdisc_create+0x7cb/0x1090 net/sched/sch_api.c:1315 tc_modify_qdisc+0xb2f/0x1cc0 net/sched/sch_api.c:-1 rtnetlink_rcv_msg+0x79b/0xed0 net/core/rtnetlink.c:6153 netlink_rcv_skb+0x1de/0x420 net/netlink/af_netlink.c:2511 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x74d/0x8d0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x89e/0xbc0 net/netlink/af_netlink.c:1872 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] ____sys_sendmsg+0x59b/0x970 net/socket.c:2519 ___sys_sendmsg+0x21c/0x290 net/socket.c:2573 __sys_sendmsg net/socket.c:2602 [inline] __do_sys_sendmsg net/socket.c:2611 [inline] __se_sys_sendmsg+0x19e/0x270 net/socket.c:2609 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fdee2b8eb69 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:00007fdee3a43038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fdee2db5fa0 RCX: 00007fdee2b8eb69 RDX: 0000000000000000 RSI: 00002000000007c0 RDI: 0000000000000005 RBP: 00007fdee2c11df1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fdee2db5fa0 R15: 00007ffdc7764bb8 rcu: rcu_preempt kthread starved for 10499 jiffies! g27953 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:27200 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706 rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 4966 Comm: kworker/u4:23 Not tainted 6.1.147-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:424 [inline] RIP: 0010:smp_call_function_many_cond+0xe7b/0x1270 kernel/smp.c:998 Code: 00 00 00 41 8b 1f 89 de 83 e6 01 31 ff e8 5d d9 0a 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 e9 d5 0a 00 eb 37 f3 90 <41> 0f b6 04 1c 84 c0 75 10 41 f7 07 01 00 00 00 74 1e e8 ce d5 0a RSP: 0018:ffffc90004a4f800 EFLAGS: 00000293 RAX: ffffffff8175f112 RBX: dffffc0000000000 RCX: ffff888020350000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90004a4f960 R08: dffffc0000000000 R09: fffffbfff215ba49 R10: fffffbfff215ba49 R11: 1ffffffff215ba48 R12: 1ffff110171c85ad R13: ffff8880b8f3bb40 R14: 0000000000000000 R15: ffff8880b8e42d68 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb027782d58 CR3: 000000000c88e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1166 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1574 [inline] text_poke_bp_batch+0x2b0/0x7d0 arch/x86/kernel/alternative.c:1774 text_poke_flush arch/x86/kernel/alternative.c:1965 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1972 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x11f/0x240 kernel/jump_label.c:207 static_key_enable+0x16/0x20 kernel/jump_label.c:220 toggle_allocation_gate+0xb4/0x430 mm/kfence/core.c:805 process_one_work+0x898/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295