INFO: task syz.5.1966:13546 blocked for more than 143 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.1966      state:D stack:25320 pid:13546 tgid:13538 ppid:5633   task_flags:0x400740 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x1840/0x57a0 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7283
 schedule_timeout+0xc0/0x2c0 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:100 [inline]
 __wait_for_common+0x3aa/0x670 kernel/sched/completion.c:121
 wait_for_common kernel/sched/completion.c:132 [inline]
 wait_for_completion_state+0x1c/0x40 kernel/sched/completion.c:269
 coredump_wait fs/coredump.c:537 [inline]
 vfs_coredump+0x9a0/0x4510 fs/coredump.c:1202
 get_signal+0x1094/0x12c0 kernel/signal.c:3023
 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
 exit_to_user_mode_loop+0xa9/0x6b0 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
 do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8b8df9ce59
RSP: 002b:00007f8b8ee070e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f8b8e216188 RCX: 00007f8b8df9ce59
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f8b8e21618c
RBP: 00007f8b8e216180 R08: 3fffffffffffffff R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8b8e216218 R14: 00007ffe63ca1890 R15: 00007ffe63ca1978
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e95c780 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8e95c780 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8e95c780 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
7 locks held by kworker/u8:6/722:
2 locks held by getty/5380:
 #0: ffff8880321780a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1380 drivers/tty/n_tty.c:2211
3 locks held by kworker/0:7/5798:
 #0: ffff88813fe3f140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #0: ffff88813fe3f140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3397
 #1: ffffc900040efc40 (rx_mode_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #1: ffffc900040efc40 (rx_mode_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3397
 #2: ffffffff8fdc06c0 (rtnl_mutex){+.+.}-{4:4}, at: netdev_rx_mode_work+0x18/0x3c0 net/core/dev_addr_lists.c:1312
3 locks held by kworker/u8:3/13923:
 #0: ffff88803209e140 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #0: ffff88803209e140 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3397
 #1: ffffc9000507fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #1: ffffc9000507fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3397
 #2: ffffffff8fdc06c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #2: ffffffff8fdc06c0 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x116/0x15c0 net/ipv6/addrconf.c:4208
1 lock held by syz-executor/13982:
 #0: ffff8880682420d8 (&type->s_umount_key#56){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff8880682420d8 (&type->s_umount_key#56){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
 #0: ffff8880682420d8 (&type->s_umount_key#56){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508
3 locks held by syz-executor/15536:
 #0: ffffffff8fdc06c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff8fdc06c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #0: ffffffff8fdc06c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a3/0x1bd0 net/core/rtnetlink.c:4109
 #1: ffff888038830dc8 (&dev_instance_lock_key#23){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2818 [inline]
 #1: ffff888038830dc8 (&dev_instance_lock_key#23){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline]
 #1: ffff888038830dc8 (&dev_instance_lock_key#23){+.+.}-{4:4}, at: do_setlink+0x3d4/0x4670 net/core/rtnetlink.c:3091
 #2: ffffffff8e962aa8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
 #2: ffffffff8e962aa8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
1 lock held by rm/15672:

=============================================

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xfd7/0x1030 kernel/hung_task.c:561
 kthread+0x389/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 15536 Comm: syz-executor Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:401
Code: e8 8e 75 82 fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 1f b3 ed fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 35 76 cd fb cc 44 89 f9 80 e1 07
RSP: 0018:ffffc90004a665f8 EFLAGS: 00000006
RAX: 1ffffffff34ee705 RBX: 00000000000003f9 RCX: 0000000000000000
RDX: 00000000000003f9 RSI: 0000000000000000 RDI: 0000000000000020
RBP: ffffc90004a66790 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: ffffffff8542ca50 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffffffff9a773ac0 R15: 0000000000000000
FS:  0000555579c42500(0000) GS:ffff8881252b9000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055fae024dfd8 CR3: 000000008052d000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 serial_port_in include/linux/serial_core.h:806 [inline]
 serial8250_console_write+0x547/0x1bd0 drivers/tty/serial/8250/8250_port.c:3324
 console_emit_next_record kernel/printk/printk.c:3183 [inline]
 console_flush_one_record kernel/printk/printk.c:3269 [inline]
 console_flush_all+0x6ea/0xaf0 kernel/printk/printk.c:3343
 __console_flush_and_unlock kernel/printk/printk.c:3373 [inline]
 console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3413
 vprintk_emit+0x485/0x560 kernel/printk/printk.c:2479
 dev_vprintk_emit+0x338/0x400 drivers/base/core.c:4930
 dev_printk_emit+0xee/0x140 drivers/base/core.c:4941
 __netdev_printk+0x3e1/0x480 net/core/dev.c:12941
 netdev_info+0x11e/0x180 net/core/dev.c:12996
 netif_change_name+0x8ad/0x980 net/core/dev.c:1485
 do_setlink+0xb66/0x4670 net/core/rtnetlink.c:3161
 rtnl_changelink net/core/rtnetlink.c:3800 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3973 [inline]
 rtnl_newlink+0x15c2/0x1bd0 net/core/rtnetlink.c:4110
 rtnetlink_rcv_msg+0x802/0xc00 net/core/rtnetlink.c:6997
 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2555
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x7bb/0x940 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1899
 sock_sendmsg_nosec net/socket.c:787 [inline]
 __sock_sendmsg net/socket.c:802 [inline]
 __sys_sendto+0x672/0x710 net/socket.c:2266
 __do_sys_sendto net/socket.c:2273 [inline]
 __se_sys_sendto net/socket.c:2269 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2269
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f591db5d68e
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007fff53a5dc58 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000555579c42500 RCX: 00007f591db5d68e
RDX: 0000000000000030 RSI: 00007f591e943610 RDI: 0000000000000006
RBP: 0000000000000001 R08: 00007fff53a5dcd4 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000006
R13: 0000000000000000 R14: 00007f591e943610 R15: 0000000000000000
 </TASK>