rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=aeb4/1/0x4000000000000000 softirq=23772/23773 fqs=2 rcu: (detected by 0, t=10503 jiffies, g=19321, q=629 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 7326 Comm: syz.9.266 Not tainted 6.12.0-syzkaller-10689-g7af08b57bcb9 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:lock_is_held_type+0x11f/0x190 kernel/locking/lockdep.c:5923 Code: 48 c7 c7 60 eb 0a 8c e8 7f 1a 00 00 b8 ff ff ff ff 65 0f c1 05 42 c9 2f 74 83 f8 01 75 44 48 c7 04 24 00 00 00 00 9c 8f 04 24 04 24 00 02 00 00 75 4c 41 f7 c4 00 02 00 00 74 01 fb 65 48 8b RSP: 0018:ffffc90000a18c28 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffff88802f0c5a00 RDX: ffff88802f0c5a00 RSI: ffffffff8c0aeb60 RDI: ffffffff8c6158a0 RBP: 0000000000000002 R08: ffffffff89d54351 R09: fffff5200014317c R10: dffffc0000000000 R11: fffff5200014317c R12: 0000000000000046 R13: ffff88802f0c5a00 R14: 00000000ffffffff R15: ffff88805dc61300 FS: 00007fa9140da6c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055aef5004131 CR3: 000000004fba8000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_is_held include/linux/lockdep.h:249 [inline] advance_sched+0x148/0xca0 net/sched/sch_taprio.c:927 __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 ee 41 24 f6 f6 44 24 21 02 75 52 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 83 6b 87 f5 65 8b 05 f4 4c 27 74 85 c0 74 43 48 c7 04 24 0e 36 RSP: 0018:ffffc90003466de0 EFLAGS: 00000206 RAX: 6b17f43c99fd3e00 RBX: 1ffff9200068cdc0 RCX: ffffffff8171939a RDX: dffffc0000000000 RSI: ffffffff8c0ad980 RDI: 0000000000000001 RBP: ffffc90003466e70 R08: ffffffff943219df R09: 1ffffffff286433b R10: dffffc0000000000 R11: fffffbfff286433c R12: dffffc0000000000 R13: 1ffff9200068cdbc R14: ffffc90003466e00 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: 0033:0x7fa913380809 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:00007fa9140da058 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fa913545fa0 RCX: 00007fa913380809 RDX: 0000000000000000 RSI: 00000000200007c0 RDI: 0000000000000006 RBP: 00007fa9133f393e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fa913545fa0 R15: 00007fa91366fa38 rcu: rcu_preempt kthread starved for 10492 jiffies! g19321 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:25784 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: 3574 Comm: kworker/u8:11 Not tainted 6.12.0-syzkaller-10689-g7af08b57bcb9 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:variable_ffs arch/x86/include/asm/bitops.h:321 [inline] RIP: 0010:handle_softirqs+0x1ef/0x9b0 kernel/softirq.c:542 Code: 00 00 00 45 0f b7 e4 48 c7 c7 a0 c9 09 8c e8 78 a0 7a 0a 65 66 c7 05 a6 99 ab 7e 00 00 e8 69 70 45 00 fb 49 c7 c6 c0 b0 60 8e ff ff ff ff 41 0f bc c4 41 89 c7 41 ff c7 0f 84 0a 04 00 00 44 RSP: 0018:ffffc90000007e20 EFLAGS: 00000282 RAX: 3e6f7d028a238100 RBX: ffffc90000007ee0 RCX: ffffffff8171939a RDX: dffffc0000000000 RSI: ffffffff8c0ad980 RDI: ffffffff8c6158a0 RBP: ffffc90000007f50 R08: ffffffff94321887 R09: 1ffffffff2864310 R10: dffffc0000000000 R11: fffffbfff2864311 R12: 0000000000000100 R13: 0000000000000000 R14: ffffffff8e60b0c0 R15: 1ffff110065c8b40 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f253490a2d8 CR3: 000000000e738000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf7/0x220 kernel/softirq.c:655 irq_exit_rcu+0x9/0x30 kernel/softirq.c:671 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 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:ffffc9000d79f6e0 EFLAGS: 00000293 RAX: ffffffff8189fcdb RBX: 1ffff110170e88c1 RCX: ffff888032e45a00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000d79f8e0 R08: ffffffff8189fcaa R09: 1ffffffff2864310 R10: dffffc0000000000 R11: fffffbfff2864311 R12: dffffc0000000000 R13: ffff8880b8744608 R14: ffff8880b863f980 R15: 0000000000000001 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:2114 [inline] text_poke_bp_batch+0x352/0xb30 arch/x86/kernel/alternative.c:2324 text_poke_flush arch/x86/kernel/alternative.c:2515 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2522 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