rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7107/1:b..l (detected by 1, t=10502 jiffies, g=24641, q=268) task:dhcpcd-run-hook state:R running task stack:26520 pid: 7107 ppid: 3174 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6780 irqentry_exit+0x53/0x80 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:lock_acquire+0x252/0x4f0 kernel/locking/lockdep.c:5627 Code: 2b 00 74 08 4c 89 f7 e8 0c 7e 67 00 f6 44 24 61 02 0f 85 84 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc90003107540 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff92000620eb4 RCX: 1ffff92000620e54 RDX: dffffc0000000000 RSI: ffffffff8a8b3ca0 RDI: ffffffff8ad8f740 RBP: ffffc900031076a0 R08: dffffc0000000000 R09: fffffbfff1f7f219 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000620eb0 R13: dffffc0000000000 R14: ffffc900031075a0 R15: 0000000000000246 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312 rcu_read_lock include/linux/rcupdate.h:739 [inline] dput+0x35/0x1a0 fs/dcache.c:875 fscrypt_file_open+0x182/0x300 fs/crypto/hooks.c:47 ext4_file_open+0x1fc/0x710 fs/ext4/file.c:857 do_dentry_open+0x807/0xfb0 fs/open.c:826 do_open fs/namei.c:3608 [inline] path_openat+0x2705/0x2f20 fs/namei.c:3742 do_filp_open+0x21c/0x460 fs/namei.c:3769 do_sys_openat2+0x13b/0x500 fs/open.c:1253 do_sys_open fs/open.c:1269 [inline] __do_sys_openat fs/open.c:1285 [inline] __se_sys_openat fs/open.c:1280 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1280 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: 0033:0x7fe3e1ae79a4 RSP: 002b:00007ffda5555820 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00005649ea39b910 RCX: 00007fe3e1ae79a4 RDX: 0000000000080000 RSI: 00005649ea3a4288 RDI: 00000000ffffff9c RBP: 00005649ea3a4288 R08: 00005649ea3a42c8 R09: 3c00000000001001 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000080000 R13: 00005649ea3a4288 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10535 jiffies! g24641 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:27256 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376 schedule+0x11b/0x1f0 kernel/sched/core.c:6459 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:300 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 1 CPU: 1 PID: 7108 Comm: syz.4.1342 Not tainted 5.15.161-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 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:1686 [inline] __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1750 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline] __sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__syscall_enter_from_user_work kernel/entry/common.c:93 [inline] RIP: 0010:syscall_enter_from_user_mode+0x37/0x240 kernel/entry/common.c:114 Code: 49 89 fe 48 8b 7c 24 30 e8 46 f6 ff ff e9 8d 01 00 00 e9 91 01 00 00 e8 97 94 68 f7 e8 82 92 68 f7 fb 65 4c 8b 3d 29 27 e4 75 <49> 8b 5f 08 f6 c3 3f 0f 84 ce 00 00 00 f6 c3 20 74 17 4c 89 f7 e8 RSP: 0018:ffffc900025b7ef8 EFLAGS: 00000282 RAX: 6fdf355008313000 RBX: ffffc900025b7f30 RCX: ffffffff913f0f03 RDX: dffffc0000000000 RSI: ffffffff8a8b2a00 RDI: ffffffff8ad8f740 RBP: ffffc900025b7f48 R08: ffffffff8186db40 R09: fffffbfff1bc8d86 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000 R13: 0000000000000027 R14: ffffc900025b7f58 R15: ffff88801c7f5940 do_syscall_64+0x1e/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f40dc78ec27 Code: 0b e9 68 fe ff ff 48 83 c4 18 48 8d 3d 72 fc cc 00 5b 5d 41 5c 41 5d 41 5e 41 5f e9 13 f5 fb 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:00007ffe1ce5e308 EFLAGS: 00000202 ORIG_RAX: 0000000000000027 RAX: ffffffffffffffda RBX: 00007ffe1ce5e470 RCX: 00007f40dc78ec27 RDX: 00007ffe1ce5e340 RSI: 00007ffe1ce5e470 RDI: 0000000000000021 RBP: 0000000000000000 R08: 0000000000000001 R09: 00007f40dbe1f000 R10: 0000000000000008 R11: 0000000000000202 R12: ffffffff8186db16 R13: 00007f40dc9260d0 R14: 0000000000000e75 R15: 00007f40dc912000 sched: RT throttling activated