rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3545/1:b..l (detected by 1, t=10503 jiffies, g=14113, q=376) task:udevd state:R running task stack:24960 pid: 3545 ppid: 1 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6549 preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6574 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] _raw_spin_unlock_irqrestore+0x128/0x130 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:418 [inline] __wake_up_common_lock kernel/sched/wait.c:140 [inline] __wake_up_sync_key+0x121/0x1c0 kernel/sched/wait.c:205 sock_def_readable+0x135/0x240 net/core/sock.c:3092 __netlink_sendskb net/netlink/af_netlink.c:1273 [inline] netlink_sendskb+0x8e/0x120 net/netlink/af_netlink.c:1279 netlink_unicast+0x3a1/0x980 net/netlink/af_netlink.c:1367 netlink_sendmsg+0xa30/0xd60 net/netlink/af_netlink.c:1920 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] ____sys_sendmsg+0x59e/0x8f0 net/socket.c:2436 ___sys_sendmsg+0x252/0x2e0 net/socket.c:2490 __sys_sendmsg net/socket.c:2519 [inline] __do_sys_sendmsg net/socket.c:2528 [inline] __se_sys_sendmsg+0x19a/0x260 net/socket.c:2526 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fe42d19da4b RSP: 002b:00007fffb73175c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000055b68bbb89e0 RCX: 00007fe42d19da4b RDX: 0000000000000000 RSI: 00007fffb73175d8 RDI: 0000000000000004 RBP: 000055b68bbde1e0 R08: 0000000000000001 R09: 0000000000000000 R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000000b3 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10533 jiffies! g14113 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:26816 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 schedule+0x11b/0x1f0 kernel/sched/core.c:6456 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 1 CPU: 1 PID: 5492 Comm: syz-executor Not tainted 5.15.171-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline] rcu_check_gp_kthread_starvation+0x1d2/0x240 kernel/rcu/tree_stall.h:487 print_other_cpu_stall+0x137a/0x14d0 kernel/rcu/tree_stall.h:592 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline] rcu_pending kernel/rcu/tree.c:3932 [inline] rcu_sched_clock_irq+0xa38/0x1150 kernel/rcu/tree.c:2619 update_process_times+0x196/0x200 kernel/time/timer.c:1818 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1688 [inline] __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x13b/0x4b0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:ns_of_pid include/linux/pid.h:154 [inline] RIP: 0010:task_active_pid_ns kernel/pid.c:509 [inline] RIP: 0010:__task_pid_nr_ns+0x116/0x420 kernel/pid.c:499 Code: e8 03 42 0f b6 04 20 84 c0 0f 85 c9 02 00 00 8b 45 04 48 c1 e0 04 48 8d ac 05 d8 00 00 00 48 89 e8 48 c1 e8 03 42 80 3c 20 00 <74> 08 48 89 ef e8 30 aa 75 00 4c 8b 75 00 eb 08 e8 95 d2 2b 00 45 RSP: 0018:ffffc900030b7ef8 EFLAGS: 00000246 RAX: 1ffff1100cce675d RBX: ffff88801dc91dc0 RCX: ffff88801dc91dc0 RDX: 0000000000000000 RSI: ffffffff8ad904e0 RDI: ffff888066733a04 RBP: ffff888066733ae8 R08: ffffffff8154a020 R09: fffffbfff20ec621 R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001 task_tgid_vnr include/linux/sched.h:1587 [inline] __do_sys_getpid+0x19/0x20 kernel/sys.c:945 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f037f815667 Code: 0b e9 68 fe ff ff 48 83 c4 18 48 8d 3d f2 01 c6 00 5b 5d 41 5c 41 5d 41 5e 41 5f e9 b3 68 fd ff 0f 1f 00 b8 27 00 00 00 0f 05 0f 1f 84 00 00 00 00 00 b8 66 00 00 00 0f 05 c3 0f 1f 84 00 00 RSP: 002b:00007f037eb98b88 EFLAGS: 00000206 ORIG_RAX: 0000000000000027 RAX: ffffffffffffffda RBX: 00007f037eb98cf0 RCX: 00007f037f815667 RDX: 00007f037eb98bc0 RSI: 00007f037eb98cf0 RDI: 0000000000000021 RBP: 0000000000000000 R08: 00007f037eb996c0 R09: 00007f037eb996c0 R10: 0000000000000000 R11: 0000000000000206 R12: 00007f037f946f8c R13: 000000000000000b R14: 00007ffc8e9064e0 R15: 00007ffc8e9065c8