rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 ticks this GP) idle=7984/1/0x4000000000000000 softirq=21524/21524 fqs=0 rcu: (detected by 0, t=10502 jiffies, g=16929, q=8997 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 6475 Comm: syz.1.17 Not tainted 6.14.0-syzkaller-13408-g9f867ba24d36 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:114 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:128 [inline] RIP: 0010:lock_is_held_type+0x72/0x1a0 kernel/locking/lockdep.c:5934 Code: 25 08 a0 68 93 41 83 bc 24 ec 0a 00 00 00 0f 85 e7 00 00 00 41 89 f6 49 89 ff 48 c7 04 24 00 00 00 00 9c 8f 04 24 4c 8b 2c 24 48 c7 c7 2e 93 76 8e e8 41 1b 00 00 65 ff 05 ba 56 38 07 41 83 RSP: 0018:ffffc90000a08c28 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 00000000ffffffff RCX: ffff8880265d9e00 RDX: ffff8880265d9e00 RSI: 00000000ffffffff RDI: ffff88805a158300 RBP: ffffffff9368a020 R08: ffffffff8a26c72b R09: fffff5200014117c R10: dffffc0000000000 R11: fffff5200014117c R12: ffff8880265d9e00 R13: 0000000000000046 R14: 00000000ffffffff R15: ffff88805a158300 FS: 00007fa9a0dbe6c0(0000) GS:ffff888125096000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa9a0d9dd58 CR3: 000000005a122000 CR4: 0000000000350ef0 Call Trace: lock_is_held include/linux/lockdep.h:249 [inline] advance_sched+0x1c2/0xca0 net/sched/sch_taprio.c:929 __run_hrtimer kernel/time/hrtimer.c:1791 [inline] __hrtimer_run_queues+0x5a8/0xd40 kernel/time/hrtimer.c:1855 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1917 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x112/0x420 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:lockdep_unregister_key+0x29a/0x2f0 kernel/locking/lockdep.c:6613 Code: f0 36 6c 94 48 c7 c6 20 14 9f 81 e8 60 bd 09 00 e8 3b c8 09 00 e9 3b fe ff ff e8 81 6e 91 0a f7 c5 00 02 00 00 74 d2 fb 84 db <75> d1 eb e2 90 0f 0b 90 e9 35 ff ff ff 90 0f 0b 90 e9 46 ff ff ff RSP: 0018:ffffc9000314f0a8 EFLAGS: 00000246 RAX: b8fcff5f9e6f6900 RBX: 0000000000000000 RCX: 000000000000ee58 RDX: ffffffff942c36e8 RSI: ffffffff8e76932e RDI: ffffffff8ca1b660 RBP: 0000000000000217 R08: ffffffff905fdf77 R09: 1ffffffff20bfbee R10: dffffc0000000000 R11: fffffbfff20bfbef R12: ffffffff9368a020 R13: 0000000000001000 R14: ffffffff946e3718 R15: ffff88805baab298 __qdisc_destroy+0x165/0x410 net/sched/sch_generic.c:1080 taprio_attach+0x24e/0x390 net/sched/sch_taprio.c:2147 qdisc_graft+0x1341/0x1670 net/sched/sch_api.c:1175 __tc_modify_qdisc net/sched/sch_api.c:1765 [inline] tc_modify_qdisc+0x1aa3/0x2610 net/sched/sch_api.c:1821 rtnetlink_rcv_msg+0x7c4/0xd70 net/core/rtnetlink.c:6964 netlink_rcv_skb+0x20a/0x480 net/netlink/af_netlink.c:2534 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x7fa/0x9a0 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x8c3/0xcd0 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x223/0x270 net/socket.c:727 ____sys_sendmsg+0x523/0x860 net/socket.c:2566 ___sys_sendmsg net/socket.c:2620 [inline] __sys_sendmsg+0x271/0x360 net/socket.c:2652 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa99ff8d169 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:00007fa9a0dbe038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fa9a01a5fa0 RCX: 00007fa99ff8d169 RDX: 0000000000000000 RSI: 00002000000007c0 RDI: 0000000000000004 RBP: 00007fa9a000e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fa9a01a5fa0 R15: 00007ffd9e974ea8 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g16929 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=6664 rcu: rcu_preempt kthread starved for 10502 jiffies! g16929 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:26688 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 schedule_timeout+0x15b/0x2b0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2e1/0x1340 kernel/rcu/tree.c:2046 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2248 kthread+0x7b9/0x940 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245