rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=6894/1/0x4000000000000000 softirq=30593/30598 fqs=1 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P45/1:b..l (detected by 1, t=10505 jiffies, g=45973, q=19 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5104 Comm: syz-executor.2 Not tainted 6.2.0-rc5-syzkaller-00013-g2475bf0250de #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023 RIP: 0010:rcu_is_watching+0x0/0xb0 kernel/rcu/tree.c:709 Code: b6 7e 63 00 eb b6 0f 1f 40 00 f3 0f 1e fa 48 c7 c7 e0 ce 4d 8a e8 30 b0 9b 08 65 8a 05 65 86 99 7e 0f b6 c0 c3 0f 1f 44 00 00 0f 1e fa 55 53 65 ff 05 ab 6c 99 7e e8 ee af 9b 08 48 c7 c3 28 RSP: 0018:ffffc90000007db0 EFLAGS: 00000046 RAX: 0000000080010001 RBX: 0000000000000001 RCX: 0000000000000000 RDX: ffff8880761a6280 RSI: ffffffff87ff4ad1 RDI: 0000000000000001 RBP: 0000000140000002 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffff888020c76300 R13: 17f802632ff004c6 R14: ffff888020c76320 R15: 17f802632ff004c6 FS: 0000555556aed400(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555556aed708 CR3: 000000003152d000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_unlock include/linux/rcupdate.h:793 [inline] advance_sched+0x4d6/0x9b0 net/sched/sch_taprio.c:755 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x690/0xfb0 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x320/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1096 [inline] __sysvec_apic_timer_interrupt+0x180/0x640 arch/x86/kernel/apic/apic.c:1113 sysvec_apic_timer_interrupt+0x92/0xc0 arch/x86/kernel/apic/apic.c:1107 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x3c/0x70 kernel/locking/spinlock.c:194 Code: 74 24 10 e8 a6 fb 59 f7 48 89 ef e8 4e 68 5a f7 81 e3 00 02 00 00 75 25 9c 58 f6 c4 02 75 2d 48 85 db 74 01 fb bf 01 00 00 00 2f ce 4c f7 65 8b 05 50 89 fa 75 85 c0 74 0a 5b 5d c3 e8 bc e1 RSP: 0018:ffffc900035b7c78 EFLAGS: 00000206 RAX: 0000000000000002 RBX: 0000000000000200 RCX: 1ffffffff1ce4199 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffff8880b982b780 R08: 0000000000000001 R09: 0000000000000001 R10: ffffed10173056f0 R11: 0000000000000000 R12: 0000000000000001 R13: dffffc0000000000 R14: ffffc900035b7dd8 R15: ffff8880761a6280 hrtimer_start_expires include/linux/hrtimer.h:432 [inline] hrtimer_sleeper_start_expires kernel/time/hrtimer.c:1965 [inline] do_nanosleep+0x131/0x4f0 kernel/time/hrtimer.c:2041 hrtimer_nanosleep+0x1fd/0x4b0 kernel/time/hrtimer.c:2097 common_nsleep+0xa6/0xd0 kernel/time/posix-timers.c:1236 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1276 [inline] __se_sys_clock_nanosleep kernel/time/posix-timers.c:1254 [inline] __x64_sys_clock_nanosleep+0x2f8/0x430 kernel/time/posix-timers.c:1254 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f495eeb0df1 Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 aa e7 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 e3 e7 ff ff 48 8b 04 24 eb 97 66 2e 0f 1f RSP: 002b:00007fff77f78880 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: ffffffffffffffda RBX: 00000000000004e6 RCX: 00007f495eeb0df1 RDX: 00007fff77f788c0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fff77f7894c R08: 0000000000000000 R09: 00007fff77ff5080 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001 R13: 0000000000094be0 R14: 0000000000000000 R15: 00007fff77f789b0 task:kworker/u4:3 state:R running task stack:25320 pid:45 ppid:2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5293 [inline] __schedule+0xb8a/0x5450 kernel/sched/core.c:6606 preempt_schedule_irq+0x52/0xa0 kernel/sched/core.c:6918 irqentry_exit+0x35/0x80 kernel/entry/common.c:432 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:654 RIP: 0010:rcu_preempt_read_exit kernel/rcu/tree_plugin.h:384 [inline] RIP: 0010:__rcu_read_unlock+0x72/0x5b0 kernel/rcu/tree_plugin.h:421 Code: 8b 24 25 40 ac 03 00 49 8d bc 24 3c 04 00 00 8b 9d 3c 04 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 <48> 89 f8 83 e0 07 83 eb 01 83 c0 03 38 d0 7c 08 84 d2 0f 85 cc 01 RSP: 0018:ffffc90000d6fc58 EFLAGS: 00000a03 RAX: dffffc0000000000 RBX: 0000000000000001 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff89947062 RDI: ffff8880179044bc RBP: ffff888017904080 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffff888017904080 R13: 0000000000000000 R14: dffffc0000000000 R15: 00000000000002f4 rcu_read_unlock include/linux/rcupdate.h:796 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline] batadv_nc_worker+0x857/0xfa0 net/batman-adv/network-coding.c:719 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289 worker_thread+0x669/0x1090 kernel/workqueue.c:2436 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 rcu: rcu_preempt kthread starved for 10500 jiffies! g45973 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:28824 pid:15 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5293 [inline] __schedule+0xb8a/0x5450 kernel/sched/core.c:6606 schedule+0xde/0x1b0 kernel/sched/core.c:6682 schedule_timeout+0x14e/0x2a0 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x190/0x910 kernel/rcu/tree.c:1656 rcu_gp_kthread+0x23a/0x360 kernel/rcu/tree.c:1855 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 5268 Comm: kworker/u4:8 Not tainted 6.2.0-rc5-syzkaller-00013-g2475bf0250de #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline] RIP: 0010:write_comp_data+0x21/0x90 kernel/kcov.c:236 Code: 2e 0f 1f 84 00 00 00 00 00 65 8b 05 61 2e 83 7e 49 89 f1 89 c6 49 89 d2 81 e6 00 01 00 00 49 89 f8 65 48 8b 14 25 40 ac 03 00 00 01 ff 00 74 0e 85 f6 74 59 8b 82 6c 15 00 00 85 c0 74 4f 8b RSP: 0018:ffffc900049a7970 EFLAGS: 00000246 RAX: 0000000000000001 RBX: ffffe8ffffc0bee0 RCX: ffffffff81758473 RDX: ffff88803515a100 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003 R13: fffff91ffff817dd R14: 0000000000000001 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd09de73d38 CR3: 000000000c48e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: csd_lock_wait kernel/smp.c:413 [inline] smp_call_function_many_cond+0x463/0x10a0 kernel/smp.c:987 on_each_cpu_cond_mask+0x5a/0xa0 kernel/smp.c:1155 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1772 [inline] text_poke_bp_batch+0x22e/0x6b0 arch/x86/kernel/alternative.c:1963 text_poke_flush arch/x86/kernel/alternative.c:2131 [inline] text_poke_flush arch/x86/kernel/alternative.c:2128 [inline] text_poke_finish+0x1a/0x30 arch/x86/kernel/alternative.c:2138 arch_jump_label_transform_apply+0x17/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x32f/0x410 kernel/jump_label.c:829 static_key_enable_cpuslocked+0x1b5/0x270 kernel/jump_label.c:205 static_key_enable+0x1a/0x20 kernel/jump_label.c:218 toggle_allocation_gate mm/kfence/core.c:799 [inline] toggle_allocation_gate+0xf8/0x230 mm/kfence/core.c:791 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289 worker_thread+0x669/0x1090 kernel/workqueue.c:2436 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308