rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4670/1:b..l P5301/1:b..l P5218/1:b..l rcu: (detected by 0, t=10502 jiffies, g=11865, q=741 ncpus=2) task:syz-executor state:R running task stack:23280 pid:5218 tgid:5218 ppid:5212 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0xe37/0x5490 kernel/sched/core.c:6529 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6708 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] copy_pte_range mm/memory.c:1191 [inline] copy_pmd_range mm/memory.c:1252 [inline] copy_pud_range mm/memory.c:1289 [inline] copy_p4d_range mm/memory.c:1313 [inline] copy_page_range+0x1c95/0x57d0 mm/memory.c:1411 dup_mmap kernel/fork.c:749 [inline] dup_mm kernel/fork.c:1672 [inline] copy_mm kernel/fork.c:1721 [inline] copy_process+0x8117/0x8de0 kernel/fork.c:2374 kernel_clone+0xfd/0x960 kernel/fork.c:2781 __do_sys_clone+0xba/0x100 kernel/fork.c:2924 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe4aeb706d3 RSP: 002b:00007ffdd22ed378 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe4aeb706d3 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 000055558438e7d0 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000001ec01 R14: 000000000001eb4f R15: 00007ffdd22ed500 task:udevd state:R running task stack:26480 pid:5301 tgid:5301 ppid:4670 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0xe37/0x5490 kernel/sched/core.c:6529 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:6851 irqentry_exit+0x36/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x1f2/0x560 kernel/locking/lockdep.c:5727 Code: c1 05 ea 13 9a 7e 83 f8 01 0f 85 ea 02 00 00 9c 58 f6 c4 02 0f 85 d5 02 00 00 48 85 ed 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffffc900036afcb0 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff920006d5f98 RCX: 0000000000000001 RDX: 0000000000000001 RSI: ffffffff8b4cc800 RDI: ffffffff8bb09b80 RBP: 0000000000000200 R08: 0000000000000000 R09: fffffbfff28c5ae0 R10: ffffffff9462d707 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8ddb5d20 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:326 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] mntput_no_expire+0xa1/0xaf0 fs/namespace.c:1399 mntput+0x6b/0x90 fs/namespace.c:1469 __fput+0x57b/0xbb0 fs/file_table.c:433 __fput_sync+0x47/0x50 fs/file_table.c:507 __do_sys_close fs/open.c:1566 [inline] __se_sys_close fs/open.c:1551 [inline] __x64_sys_close+0x86/0x100 fs/open.c:1551 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2d2a3170a8 RSP: 002b:00007ffdf314e7c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 00005636aa279c80 RCX: 00007f2d2a3170a8 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000000000b RBP: 00005636aa279c80 R08: 0000000000000007 R09: dbe8dc0b6ad975dd R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001 task:udevd state:R running task stack:26448 pid:4670 tgid:4670 ppid:1 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0xe37/0x5490 kernel/sched/core.c:6529 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6708 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0x61/0x80 kernel/locking/spinlock.c:194 sock_def_readable+0x160/0x610 net/core/sock.c:3374 __netlink_sendskb net/netlink/af_netlink.c:1278 [inline] netlink_sendskb net/netlink/af_netlink.c:1284 [inline] netlink_unicast+0x6f1/0x7f0 net/netlink/af_netlink.c:1372 netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] ____sys_sendmsg+0xab5/0xc90 net/socket.c:2597 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2651 __sys_sendmsg+0x117/0x1f0 net/socket.c:2680 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2d2a324a4b RSP: 002b:00007ffdf3153d48 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00005636aa231240 RCX: 00007f2d2a324a4b RDX: 0000000000000000 RSI: 00007ffdf3153d58 RDI: 0000000000000004 RBP: 00005636aa259a00 R08: 0000000000000001 R09: 0000000000000000 R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000000b2 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10563 jiffies! g11865 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:27584 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0xe37/0x5490 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6621 schedule_timeout+0x136/0x2a0 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2034 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2236 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 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: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x1a/0x20 drivers/acpi/processor_idle.c:111