rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=ceac/1/0x4000000000000000 softirq=11356/11357 fqs=1 rcu: (detected by 0, t=10502 jiffies, g=8717, q=420 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5934 Comm: syz-executor268 Not tainted 6.12.0-syzkaller-10681-g65ae975e97d5 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:check_preemption_disabled+0x19/0x120 lib/smp_processor_id.c:14 Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 41 57 41 56 41 54 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 <65> 8b 1d 0c 9a 30 74 65 8b 05 01 9a 30 74 a9 ff ff ff 7f 74 26 65 RSP: 0018:ffffc90000a189e8 EFLAGS: 00000086 RAX: 10af6b429d389f00 RBX: ffffc90000a18a80 RCX: ffff888023cdc6d8 RDX: dffffc0000000000 RSI: ffffffff8c0aeb60 RDI: ffffffff8c6158a0 RBP: ffffc90000a18b68 R08: ffffffff94323887 R09: 1ffffffff2864710 R10: dffffc0000000000 R11: fffffbfff2864711 R12: 1ffff9200014314c R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000046 FS: 00007f8fd8a5a6c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000600 CR3: 0000000065598000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:467 [inline] lock_acquire+0x1fd/0x550 kernel/locking/lockdep.c:5851 __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_deactivate+0x158/0x390 lib/debugobjects.c:873 debug_hrtimer_deactivate kernel/time/hrtimer.c:433 [inline] debug_deactivate+0x1b/0x220 kernel/time/hrtimer.c:475 __run_hrtimer kernel/time/hrtimer.c:1707 [inline] __hrtimer_run_queues+0x305/0xd50 kernel/time/hrtimer.c:1803 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1865 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:lockdep_unregister_key+0x56d/0x610 kernel/locking/lockdep.c:6593 Code: 2d 94 48 c7 c6 60 71 71 81 e8 6f 26 0a 00 e8 da 3a 0a 00 e9 e5 fb ff ff e8 e0 ac 61 0a 41 f7 c7 00 02 00 00 74 d0 fb 45 84 f6 <75> cf eb e0 90 0f 0b 90 45 31 f6 e9 62 ff ff ff 90 0f 0b 90 e9 a1 RSP: 0018:ffffc900043bf0a0 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 1ffff92000877e1c RCX: ffffffff9a42a903 RDX: 0000000000000001 RSI: ffffffff8c0ae6c0 RDI: ffffffff8c6158a0 RBP: ffffc900043bf168 R08: ffffffff942f449f R09: 1ffffffff285e893 R10: dffffc0000000000 R11: fffffbfff285e894 R12: ffffc900043bf0e0 R13: 1ffff92000877e18 R14: 0000000000000000 R15: 0000000000000a03 __qdisc_destroy+0x165/0x410 net/sched/sch_generic.c:1085 taprio_attach+0x24e/0x390 net/sched/sch_taprio.c:2149 qdisc_graft+0x133c/0x1660 net/sched/sch_api.c:1175 tc_modify_qdisc+0xf47/0x1e40 net/sched/sch_api.c:1793 rtnetlink_rcv_msg+0x73f/0xcf0 net/core/rtnetlink.c:6926 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2542 netlink_unicast_kernel net/netlink/af_netlink.c:1321 [inline] netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1347 netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1891 sock_sendmsg_nosec net/socket.c:711 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:726 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2583 ___sys_sendmsg net/socket.c:2637 [inline] __sys_sendmsg+0x269/0x350 net/socket.c:2669 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: 0033:0x7f8fd92b1569 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 1f 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:00007f8fd8a5a168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f8fd933b1c8 RCX: 00007f8fd92b1569 RDX: 0000000000000000 RSI: 00000000200007c0 RDI: 0000000000000004 RBP: 00007f8fd933b1c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000008 R11: 0000000000000246 R12: 00007f8fd933b1cc R13: 000000000000000b R14: 00007ffcdb4ff550 R15: 00007ffcdb4ff638 rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g8717 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=5443 rcu: rcu_preempt kthread starved for 10500 jiffies! g8717 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:26072 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x1850/0x4c30 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 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