rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 2660 jiffies s: 156457 root: 0x2/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 29885 Comm: syz.6.5864 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:125 [inline]
RIP: 0010:lockdep_hardirqs_on_prepare+0xe9/0x7c0 kernel/locking/lockdep.c:4368
Code: e8 03 0f b6 04 10 84 c0 0f 85 57 05 00 00 83 3d 3c ab 63 16 00 75 79 c6 44 13 04 00 48 c7 44 24 40 00 00 00 00 9c 8f 44 24 40 <f7> 44 24 40 00 02 00 00 c6 44 13 04 f8 0f 85 c6 03 00 00 48 c7 c0
RSP: 0018:ffffc900001e0800 EFLAGS: 00000046
RAX: 0000000000000004 RBX: 1ffff9200003c104 RCX: ffffffff97c77103
RDX: dffffc0000000000 RSI: 0000000000000001 RDI: ffffffff8db747e0
RBP: ffffc900001e08c0 R08: ffff8880b8d357cb R09: 1ffff110171a6af9
R10: dffffc0000000000 R11: ffffed10171a6afa R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f7723e196c0(0000) GS:ffff8880b8d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055ae719554b0 CR3: 0000000058afb000 CR4: 00000000003506e0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 trace_hardirqs_on+0x34/0x40 kernel/trace/trace_preemptirq.c:49
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:728
RIP: 0010:rcu_read_unlock_special+0x7f/0x510 kernel/rcu/tree_plugin.h:685
Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 d2 68 95 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08
RSP: 0018:ffffc900001e0980 EFLAGS: 00000206
RAX: 4fef7cb28a056600 RBX: 1ffff9200003c138 RCX: 4fef7cb28a056600
RDX: dffffc0000000000 RSI: ffffffff8aac19a0 RDI: ffffffff8aff71e0
RBP: ffffc900001e0a80 R08: ffffffff91b70337 R09: 1ffffffff236e066
R10: dffffc0000000000 R11: fffffbfff236e067 R12: 0000000000000246
R13: dffffc0000000000 R14: ffff8880b8d3bb00 R15: 0000000000000002
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426
 rcu_read_unlock include/linux/rcupdate.h:823 [inline]
 hsr_announce+0x2ca/0x340 net/hsr/hsr_device.c:427
 call_timer_fn+0x1ac/0x670 kernel/time/timer.c:1701
 expire_timers kernel/time/timer.c:1752 [inline]
 __run_timers+0x56c/0x810 kernel/time/timer.c:2023
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:2036
 handle_softirqs+0x291/0x910 kernel/softirq.c:596
 __do_softirq kernel/softirq.c:630 [inline]
 invoke_softirq kernel/softirq.c:470 [inline]
 __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:kernfs_ns_enabled include/linux/kernfs.h:391 [inline]
RIP: 0010:kernfs_add_one+0xad/0x8f0 fs/kernfs/dir.c:771
Code: 41 be d8 00 00 00 4d 03 75 00 4c 89 f7 e8 4b e9 3c 08 4c 89 7c 24 18 4d 8d af 98 00 00 00 4c 89 e8 48 c1 e8 03 42 0f b6 04 20 <84> c0 0f 85 9b 07 00 00 4c 89 34 24 41 0f b7 6d 00 41 89 ed 41 83
RSP: 0018:ffffc900042677d0 EFLAGS: 00000a02
RAX: 0000000000000000 RBX: ffff88807e621910 RCX: 0000000000000000
RDX: 0000000000000001 RSI: 0000000000000008 RDI: 00000000ffffffff
RBP: ffffffff8ed83bc0 R08: ffff8880184734e7 R09: 1ffff1100308e69c
R10: dffffc0000000000 R11: ffffed100308e69d R12: dffffc0000000000
R13: ffff8880632fac60 R14: ffff8880184734d8 R15: ffff8880632fabc8
 __kernfs_create_file+0x233/0x2e0 fs/kernfs/file.c:1097
 sysfs_add_file_mode_ns+0x233/0x2f0 fs/sysfs/file.c:298
 create_files fs/sysfs/group.c:64 [inline]
 internal_create_group+0x490/0xce0 fs/sysfs/group.c:148
 internal_create_groups fs/sysfs/group.c:188 [inline]
 sysfs_create_groups+0x55/0x120 fs/sysfs/group.c:214
 device_add_groups drivers/base/core.c:2752 [inline]
 device_add_attrs+0x1ae/0x830 drivers/base/core.c:2911
 device_add+0x677/0x1050 drivers/base/core.c:3648
 netdev_register_kobject+0x184/0x320 net/core/net-sysfs.c:2013
 register_netdevice+0x133a/0x1b80 net/core/dev.c:10244
 ppp_unit_register drivers/net/ppp/ppp_generic.c:1224 [inline]
 ppp_dev_configure+0x875/0xad0 drivers/net/ppp/ppp_generic.c:1280
 ppp_create_interface drivers/net/ppp/ppp_generic.c:3378 [inline]
 ppp_unattached_ioctl drivers/net/ppp/ppp_generic.c:1065 [inline]
 ppp_ioctl+0x8eb/0x1b20 drivers/net/ppp/ppp_generic.c:731
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f7722f9f559
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f7723e19028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f7723225fa0 RCX: 00007f7722f9f559
RDX: 000000110e22fff6 RSI: 00000000c004743e RDI: 0000000000000009
RBP: 00007f7723036b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7723226038 R14: 00007f7723225fa0 R15: 00007ffdac8b66f8
 </TASK>