rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 1, t=10502 jiffies, g=5761, q=61) rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294953445-4294942942), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor.5 R running task 24584 8109 8107 0x0000400a Call Trace: sched_show_task+0x40f/0x560 kernel/sched/core.c:5954 print_other_cpu_stall kernel/rcu/tree_stall.h:410 [inline] check_cpu_stall kernel/rcu/tree_stall.h:538 [inline] rcu_pending kernel/rcu/tree.c:2827 [inline] rcu_sched_clock_irq+0x1861/0x1ad0 kernel/rcu/tree.c:2271 update_process_times+0x12d/0x180 kernel/time/timer.c:1726 tick_sched_handle kernel/time/tick-sched.c:167 [inline] tick_sched_timer+0x263/0x420 kernel/time/tick-sched.c:1310 __run_hrtimer kernel/time/hrtimer.c:1514 [inline] __hrtimer_run_queues+0x403/0x840 kernel/time/hrtimer.c:1576 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1638 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline] smp_apic_timer_interrupt+0x109/0x280 arch/x86/kernel/apic/apic.c:1135 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:check_kcov_mode kernel/kcov.c:79 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x22/0x50 kernel/kcov.c:102 Code: 64 02 3b 00 5b 5d c3 cc 48 8b 04 24 65 48 8b 0c 25 c0 1d 02 00 65 8b 15 b8 81 8b 7e f7 c2 00 01 1f 00 75 2c 8b 91 80 13 00 00 <83> fa 02 75 21 48 8b 91 88 13 00 00 48 8b 32 48 8d 7e 01 8b 89 84 RSP: 0018:ffffc900025874f0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: ffffffff81487326 RBX: ffffea000248f1c0 RCX: ffff8880989e05c0 RDX: 0000000000000000 RSI: 00000000fffffffc RDI: ffffea000248f1c0 RBP: ffffc90002587518 R08: 000000000003a768 R09: ffffed1012c1ca9f R10: ffffed1012c1ca9f R11: 0000000000000000 R12: ffff88809361f820 R13: dffffc0000000000 R14: 00000000fffffffc R15: ffff8880960e54e8 free_thread_stack+0x168/0x590 kernel/fork.c:280 release_task_stack kernel/fork.c:440 [inline] put_task_stack+0xa3/0x130 kernel/fork.c:451 finish_task_switch+0x3f1/0x550 kernel/sched/core.c:3256 context_switch kernel/sched/core.c:3388 [inline] __schedule+0x9a8/0xcc0 kernel/sched/core.c:4081 preempt_schedule_common kernel/sched/core.c:4236 [inline] preempt_schedule+0xdb/0x120 kernel/sched/core.c:4261 ___preempt_schedule+0x16/0x18 arch/x86/entry/thunk_64.S:50 try_to_wake_up+0xe78/0x1050 kernel/sched/core.c:2650 wake_up_process kernel/sched/core.c:2668 [inline] wake_up_q+0x8c/0xe0 kernel/sched/core.c:496 __mutex_unlock_slowpath+0x586/0x5b0 kernel/locking/mutex.c:1283 mutex_unlock+0x1b/0x30 kernel/locking/mutex.c:743 __rtnl_unlock+0x2c/0xa0 net/core/rtnetlink.c:98 netdev_run_todo+0xe5/0xe10 net/core/dev.c:9545 rtnl_unlock net/core/rtnetlink.c:112 [inline] rtnetlink_rcv_msg+0x890/0xd40 net/core/rtnetlink.c:5423 netlink_rcv_skb+0x19e/0x3d0 net/netlink/af_netlink.c:2477 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5440 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline] netlink_unicast+0x767/0x920 net/netlink/af_netlink.c:1328 netlink_sendmsg+0xa21/0xd40 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:639 [inline] sock_sendmsg net/socket.c:659 [inline] __sys_sendto+0x442/0x5e0 net/socket.c:1985 __do_sys_sendto net/socket.c:1997 [inline] __se_sys_sendto net/socket.c:1993 [inline] __x64_sys_sendto+0xe5/0x100 net/socket.c:1993 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x414373 Code: ff 0f 83 b0 19 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 83 3d fd 40 66 00 00 75 17 49 89 ca b8 2c 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 81 19 00 00 c3 48 83 ec 08 e8 87 fa ff ff RSP: 002b:00007ffc0c4488a8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000a72200 RCX: 0000000000414373 RDX: 0000000000000028 RSI: 0000000000a72250 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffc0c4488b0 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000a72250 R15: 0000000000000003 rcu: rcu_preempt kthread starved for 10541 jiffies! g5761 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29032 10 2 0x80004000 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x9a0/0xcc0 kernel/sched/core.c:4081 schedule+0x181/0x210 kernel/sched/core.c:4155 schedule_timeout+0x14f/0x240 kernel/time/timer.c:1895 rcu_gp_fqs_loop kernel/rcu/tree.c:1661 [inline] rcu_gp_kthread+0xed8/0x1770 kernel/rcu/tree.c:1821 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352