rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=cce4/1/0x4000000000000000 softirq=21855/21868 fqs=1 rcu: (detected by 0, t=10502 jiffies, g=16409, q=499 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 8327 Comm: syz.2.693 Not tainted 6.12.0-syzkaller-05480-gfcc79e1714e8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 RIP: 0010:debug_object_deactivate+0x0/0x390 lib/debugobjects.c:862 Code: 89 ee e8 e3 1e 32 00 e9 02 ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 RSP: 0018:ffffc90000a18d18 EFLAGS: 00000006 RAX: ffffffff8182918c RBX: ffff88805a794340 RCX: ffff888026505a00 RDX: 0000000000010000 RSI: ffffffff8c0cf7e0 RDI: ffff88805a794340 RBP: ffffc90000a18ea0 R08: ffffffff81825e54 R09: 0000000000000000 R10: ffff88805a794340 R11: ffffed100b4f286b R12: 1ffff110170e593b R13: dffffc0000000000 R14: ffff88805a794340 R15: ffff8880b872c980 FS: 00007f64c46366c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd320a656c0 CR3: 0000000079270000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: 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: 2b 94 48 c7 c6 c0 e2 70 81 e8 3f 27 0a 00 e8 aa 3b 0a 00 e9 e5 fb ff ff e8 80 30 5e 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:ffffc9001c5a70a0 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 1ffff920038b4e1c RCX: ffffffff9a413903 RDX: 0000000000000001 RSI: ffffffff8c0ae040 RDI: ffffffff8c6131e0 RBP: ffffc9001c5a7168 R08: ffffffff942ddb67 R09: 1ffffffff285bb6c R10: dffffc0000000000 R11: fffffbfff285bb6d R12: ffffc9001c5a70e0 R13: 1ffff920038b4e18 R14: 0000000000000000 R15: 0000000000000206 __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:6920 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2541 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: 0033:0x7f64c377e819 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:00007f64c4636038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f64c3936080 RCX: 00007f64c377e819 RDX: 0000000000000000 RSI: 00000000200007c0 RDI: 000000000000000a RBP: 00007f64c37f175e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f64c3936080 R15: 00007fffbad9c238 rcu: rcu_preempt kthread starved for 10500 jiffies! g16409 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 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: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 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 151 Comm: kworker/u8:5 Not tainted 6.12.0-syzkaller-05480-gfcc79e1714e8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:rep_nop arch/x86/include/asm/vdso/processor.h:13 [inline] RIP: 0010:cpu_relax arch/x86/include/asm/vdso/processor.h:18 [inline] RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x19f1/0x2ca0 kernel/smp.c:884 Code: 00 00 45 8b 65 00 44 89 e6 83 e6 01 31 ff e8 e6 e8 0b 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 91 e4 0b 00 eb 38 90 42 0f b6 04 23 84 c0 75 11 41 f7 45 00 01 00 00 00 74 1e e8 RSP: 0018:ffffc90002ebf6e0 EFLAGS: 00000293 RAX: ffffffff81891e6b RBX: 1ffff110170e88e9 RCX: ffff888021f71e00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90002ebf8e0 R08: ffffffff81891e3a R09: 1ffffffff2861910 R10: dffffc0000000000 R11: fffffbfff2861911 R12: dffffc0000000000 R13: ffff8880b8744748 R14: ffff8880b863fac0 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555827be808 CR3: 000000000e738000 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