rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=b9bc/1/0x4000000000000000 softirq=46061/46062 fqs=0 rcu: (detected by 0, t=10502 jiffies, g=47677, q=344 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 10759 Comm: syz.6.1204 Not tainted 6.12.0-next-20241128-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:__lock_acquire+0xeec/0x2100 kernel/locking/lockdep.c:5221 Code: cb 01 d6 29 da 89 dd c1 c5 13 31 d5 01 f3 29 ee 01 eb c1 c5 04 31 f5 48 c1 e5 20 48 c7 c0 54 d1 19 90 48 c1 e8 03 0f b6 04 38 <84> c0 0f 85 9f 0c 00 00 48 09 dd 83 3d b6 0d 9f 0e 00 4d 89 e5 0f RSP: 0018:ffffc90000a18a10 EFLAGS: 00000803 RAX: 0000000000000000 RBX: 00000000c8d5ebdc RCX: 000000001058aa7d RDX: 00000000fae9315e RSI: 000000001b5d732a RDI: dffffc0000000000 RBP: 58cce5e700000000 R08: ffffffff942c4887 R09: 1ffffffff2858910 R10: dffffc0000000000 R11: fffffbfff2858911 R12: ffff8880302a8000 R13: ffff8880302a8000 R14: 0000000000004022 R15: 0000000000000001 FS: 00007fc9d2aab6c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4c14877d60 CR3: 000000007a442000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] advance_sched+0xa1e/0xca0 net/sched/sch_taprio.c:985 __run_hrtimer kernel/time/hrtimer.c:1739 [inline] __hrtimer_run_queues+0x59b/0xd30 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:__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 5e c5 33 f6 f6 44 24 21 02 75 52 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 63 e5 96 f5 65 8b 05 a4 34 2d 74 85 c0 74 43 48 c7 04 24 0e 36 RSP: 0018:ffffc9000466ede0 EFLAGS: 00000206 RAX: 1ba8c9a5c022b900 RBX: 1ffff920008cddc0 RCX: ffffffff817b270a RDX: dffffc0000000000 RSI: ffffffff8c0a96a0 RDI: 0000000000000001 RBP: ffffc9000466ee70 R08: ffffffff942c4a6f R09: 1ffffffff285894d R10: dffffc0000000000 R11: fffffbfff285894e R12: dffffc0000000000 R13: 1ffff920008cddbc R14: ffffc9000466ee00 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: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: 0033:0x7fc9d1d80809 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:00007fc9d2aab058 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fc9d1f45fa0 RCX: 00007fc9d1d80809 RDX: 0000000000000000 RSI: 00000000200007c0 RDI: 0000000000000004 RBP: 00007fc9d1df393e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fc9d1f45fa0 R15: 00007fff23d9ef18 rcu: rcu_preempt kthread starved for 10502 jiffies! g47677 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:25848 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: 11 Comm: kworker/u8:0 Not tainted 6.12.0-next-20241128-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x19f3/0x2c60 kernel/smp.c:884 Code: 45 8b 65 00 44 89 e6 83 e6 01 31 ff e8 66 e9 0b 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 11 e5 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 f5 e4 RSP: 0018:ffffc900001076e0 EFLAGS: 00000293 RAX: ffffffff8193900b RBX: 1ffff110170e88e9 RCX: ffff88801cac3c00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900001078e0 R08: ffffffff81938fda R09: 1ffffffff2858910 R10: dffffc0000000000 R11: fffffbfff2858911 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: 0000000020032000 CR3: 000000000e736000 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:2118 [inline] text_poke_bp_batch+0x352/0xb30 arch/x86/kernel/alternative.c:2328 text_poke_flush arch/x86/kernel/alternative.c:2519 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2526 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+0xa66/0x1840 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