rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=0134/1/0x4000000000000000 softirq=34325/34326 fqs=2 rcu: (detected by 0, t=10502 jiffies, g=43593, q=526 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 11693 Comm: syz-executor.2 Not tainted 6.9.0-syzkaller-08544-g4b377b4868ef #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline] RIP: 0010:write_comp_data kernel/kcov.c:236 [inline] RIP: 0010:__sanitizer_cov_trace_cmp8+0x11/0x90 kernel/kcov.c:284 Code: 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 4c 8b 04 24 65 48 8b 0c 25 80 d3 03 00 <65> 8b 05 40 9f 6d 7e a9 00 01 ff 00 74 10 a9 00 01 00 00 74 57 83 RSP: 0018:ffffc90000a18c88 EFLAGS: 00000046 RAX: 1ffff1100f1fcda6 RBX: ffff888078fe6d30 RCX: ffff88802a355a00 RDX: ffff88802a355a00 RSI: 0000000000000004 RDI: 0000000000000004 RBP: 1ffff1100f1fcf00 R08: ffffffff8990e893 R09: fffff52000143180 R10: dffffc0000000000 R11: fffff52000143180 R12: 0000000000000004 R13: ffff888078fe7800 R14: 0000000000000004 R15: 0000000000000000 FS: 00007fec652696c0(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5a1e8d56c6 CR3: 0000000059e9c000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: advance_sched+0x583/0xca0 net/sched/sch_taprio.c:961 __run_hrtimer kernel/time/hrtimer.c:1687 [inline] __hrtimer_run_queues+0x5a5/0xd50 kernel/time/hrtimer.c:1751 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1813 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline] __sysvec_apic_timer_interrupt+0x110/0x3f0 arch/x86/kernel/apic/apic.c:1049 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1043 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 8e 97 68 f6 f6 44 24 21 02 75 52 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 83 cc d2 f5 65 8b 05 f4 f9 70 74 85 c0 74 43 48 c7 04 24 0e 36 RSP: 0018:ffffc9000397eb40 EFLAGS: 00000206 RAX: b5e93702721d5300 RBX: 1ffff9200072fd6c RCX: ffffffff8172ea4a RDX: dffffc0000000000 RSI: ffffffff8bcab5c0 RDI: 0000000000000001 RBP: ffffc9000397ebd0 R08: ffffffff92f9c6af R09: 1ffffffff25f38d5 R10: dffffc0000000000 R11: fffffbfff25f38d6 R12: dffffc0000000000 R13: 1ffff9200072fd68 R14: ffffc9000397eb60 R15: 0000000000000246 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] taprio_change+0x339b/0x42d0 net/sched/sch_taprio.c:1971 taprio_init+0x9da/0xc80 net/sched/sch_taprio.c:2112 qdisc_create+0x9d4/0x11a0 net/sched/sch_api.c:1355 tc_modify_qdisc+0xa26/0x1e40 net/sched/sch_api.c:1777 rtnetlink_rcv_msg+0x89b/0x10d0 net/core/rtnetlink.c:6595 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2564 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x8e1/0xcb0 net/netlink/af_netlink.c:1905 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2584 ___sys_sendmsg net/socket.c:2638 [inline] __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2667 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fec6447cee9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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:00007fec652690c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fec645abf80 RCX: 00007fec6447cee9 RDX: 0000000000000000 RSI: 00000000200007c0 RDI: 0000000000000005 RBP: 00007fec644c949e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fec645abf80 R15: 00007ffca4bd52e8 rcu: rcu_preempt kthread starved for 10492 jiffies! g43593 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:24016 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0x17e8/0x4a50 kernel/sched/core.c:6745 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6837 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x2df/0x1370 kernel/rcu/tree.c:2000 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2202 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 PID: 11 Comm: kworker/u8:0 Not tainted 6.9.0-syzkaller-08544-g4b377b4868ef #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:get_current arch/x86/include/asm/current.h:49 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:206 Code: 8b 3d 3c c1 44 0c 48 89 de 5b e9 93 bd 59 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0c 25 80 d3 03 00 65 8b 15 a0 a1 6d 7e f7 c2 00 01 ff 00 RSP: 0018:ffffc900001076d8 EFLAGS: 00000202 RAX: ffffffff818a299c RBX: 1ffff110172a8879 RCX: ffff888016ec3c00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900001078e0 R08: ffffffff818a296b R09: 1ffffffff25f38b0 R10: dffffc0000000000 R11: fffffbfff25f38b1 R12: dffffc0000000000 R13: ffff8880b95443c8 R14: ffff8880b943f780 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f55780d35c0 CR3: 000000000e132000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: csd_lock_wait kernel/smp.c:311 [inline] smp_call_function_many_cond+0x18ac/0x2a00 kernel/smp.c:855 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1023 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2069 [inline] text_poke_bp_batch+0x352/0xb30 arch/x86/kernel/alternative.c:2279 text_poke_flush arch/x86/kernel/alternative.c:2470 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2477 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_disable_cpuslocked+0xce/0x1c0 kernel/jump_label.c:235 static_key_disable+0x1a/0x20 kernel/jump_label.c:243 toggle_allocation_gate+0x1b8/0x250 mm/kfence/core.c:831 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd70 kernel/workqueue.c:3393 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