INFO: task syz.7.4966:24165 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.7.4966      state:D stack:29000 pid:24165 tgid:24164 ppid:20668  task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5295 [inline]
 __schedule+0xfee/0x60e0 kernel/sched/core.c:6907
 __schedule_loop kernel/sched/core.c:6989 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7004
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
 sync_bdevs+0x153/0x480 block/bdev.c:1304
 ksys_sync+0xb0/0xf0 fs/sync.c:105
 __do_sys_sync+0xe/0x20 fs/sync.c:111
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f46b1f9bf79
RSP: 002b:00007f46b2eef028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f46b2215fa0 RCX: 00007f46b1f9bf79
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f46b2215fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f46b2216038 R14: 00007f46b2215fa0 R15: 00007ffd5e983218
 </TASK>
INFO: task syz.7.4966:24166 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.7.4966      state:D stack:28136 pid:24166 tgid:24164 ppid:20668  task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5295 [inline]
 __schedule+0xfee/0x60e0 kernel/sched/core.c:6907
 __schedule_loop kernel/sched/core.c:6989 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7004
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
 sync_bdevs+0x153/0x480 block/bdev.c:1304
 ksys_sync+0xb0/0xf0 fs/sync.c:105
 __do_sys_sync+0xe/0x20 fs/sync.c:111
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f46b1f9bf79
RSP: 002b:00007f46b2ece028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f46b2216090 RCX: 00007f46b1f9bf79
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f46b2216090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f46b2216128 R14: 00007f46b2216090 R15: 00007ffd5e983218
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/30:
 #0: ffffffff8e7e94a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 #0: ffffffff8e7e94a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
 #0: ffffffff8e7e94a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:3/49:
 #0: ffff88801ef37948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x1287/0x1920 kernel/workqueue.c:3250
 #1: ffffc90000b97d08 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x93c/0x1920 kernel/workqueue.c:3251
6 locks held by kworker/u8:8/1140:
 #0: ffff88813fe9c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1287/0x1920 kernel/workqueue.c:3250
 #1: ffffc900044efd08 ((work_completion)(&buf->work)){+.+.}-{0:0}, at: process_one_work+0x93c/0x1920 kernel/workqueue.c:3251
 #2: ffff88801ba820b8 (&buf->lock){+.+.}-{4:4}, at: flush_to_ldisc+0x34/0x730 drivers/tty/tty_buffer.c:467
 #3: ffff88805cfcb0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref+0x21/0x90 drivers/tty/tty_ldisc.c:263
 #4: ffff88805cfcb2e8 (&tty->termios_rwsem){++++}-{4:4}, at: class_rwsem_read_constructor include/linux/rwsem.h:259 [inline]
 #4: ffff88805cfcb2e8 (&tty->termios_rwsem){++++}-{4:4}, at: n_tty_receive_buf_common+0x85/0x1980 drivers/tty/n_tty.c:1678
 #5: ffffc9000ed6c380 (&ldata->output_lock){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
 #5: ffffc9000ed6c380 (&ldata->output_lock){+.+.}-{4:4}, at: commit_echoes+0x50/0x260 drivers/tty/n_tty.c:736
2 locks held by kworker/u8:10/3570:
2 locks held by getty/5570:
 #0: ffff888033dd10a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000332e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211
6 locks held by kworker/1:30/15364:
 #0: ffff888021292548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1287/0x1920 kernel/workqueue.c:3250
 #1: ffffc9000d36fd08 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x93c/0x1920 kernel/workqueue.c:3251
 #2: ffff88802acae198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
 #2: ffff88802acae198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
 #3: ffff88802acc6518 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3252 [inline]
 #3: ffff88802acc6518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline]
 #3: ffff88802acc6518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 #3: ffff88802acc6518 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
 #3: ffff88802acc6518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x2bd2/0x4af0 drivers/usb/core/hub.c:5953
 #4: ffff88802a554c68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5465 [inline]
 #4: ffff88802a554c68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 #4: ffff88802a554c68 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
 #4: ffff88802a554c68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x2bfb/0x4af0 drivers/usb/core/hub.c:5953
 #5: ffffffff8fbadc50 (ehci_cf_port_reset_rwsem){.+.+}-{4:4}, at: hub_port_reset+0x1a5/0x1c60 drivers/usb/core/hub.c:3067
1 lock held by udevd/23223:
 #0: ffff88801cac8188 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1185
1 lock held by udevd/23232:
 #0: ffff888027d01358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:961
1 lock held by udevd/23807:
 #0: ffff88801cac8188 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1185
1 lock held by udevd/23810:
 #0: ffff88801cac8188 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1185
1 lock held by udevd/23825:
1 lock held by syz.7.4966/24165:
 #0: ffff888027d01358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x153/0x480 block/bdev.c:1304
1 lock held by syz.7.4966/24166:
 #0: ffff888027d01358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x153/0x480 block/bdev.c:1304
2 locks held by kworker/u8:11/24377:
 #0: ffff88813fe9c948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x1287/0x1920 kernel/workqueue.c:3250
 #1: ffffc9000ce4fd08 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x93c/0x1920 kernel/workqueue.c:3251
3 locks held by kworker/0:4/24399:
 #0: ffff88813fe63548 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1287/0x1920 kernel/workqueue.c:3250
 #1: ffffc9000da7fd08 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x93c/0x1920 kernel/workqueue.c:3251
 #2: ffff888032929240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1b8/0x63b0 drivers/net/netdevsim/fib.c:1490
1 lock held by syz.4.5569/26402:
 #0: ffff88801cac8188 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_add_one+0x38/0x850 fs/kernfs/dir.c:796
6 locks held by syz.1.5564/26426:
4 locks held by dhcpcd-run-hook/26433:

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x141/0x190 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
 watchdog+0xd25/0x1050 kernel/hung_task.c:515
 kthread+0x370/0x450 kernel/kthread.c:467
 ret_from_fork+0x754/0xd80 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: 5167 Comm: klogd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:its_return_thunk+0x0/0x10 arch/x86/lib/retpoline.S:417
Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc <c3> cc 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 e9 2b 8f e4 f5 cc
RSP: 0018:ffffc900038f77b8 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffffffff8bb06381 RCX: ffffffff8b8a95f9
RDX: 0000000000000063 RSI: 000000000000002a RDI: ffff8880374fc900
RBP: ffffc900038f7860 R08: 0000000000000001 R09: 000000000000002a
R10: 0000000000000063 R11: 00000000000c1f18 R12: 0000000000000063
R13: ffffc900038f78f0 R14: ffffffff8bb06380 R15: 0000000000000033
FS:  00007fb890180c80(0000) GS:ffff888124352000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000557f5642c300 CR3: 0000000036d56000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000000c DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 format_decode+0x319/0xcd0 lib/vsprintf.c:2714
 vsnprintf+0x1c0/0x1240 lib/vsprintf.c:2890
 snprintf+0xc7/0x100 lib/vsprintf.c:3042
 print_caller kernel/printk/printk.c:1368 [inline]
 info_print_prefix+0x134/0x350 kernel/printk/printk.c:1387
 record_print_text+0x143/0x3c0 kernel/printk/printk.c:1434
 syslog_print+0x46c/0x620 kernel/printk/printk.c:1645
 do_syslog+0x5bd/0x6d0 kernel/printk/printk.c:1763
 __do_sys_syslog kernel/printk/printk.c:1855 [inline]
 __se_sys_syslog kernel/printk/printk.c:1853 [inline]
 __x64_sys_syslog+0x74/0xb0 kernel/printk/printk.c:1853
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb89034aa37
Code: 73 01 c3 48 8b 0d c1 f3 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 67 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 91 f3 0c 00 f7 d8 64 89 01 48
RSP: 002b:00007fffd2e18938 EFLAGS: 00000206 ORIG_RAX: 0000000000000067
RAX: ffffffffffffffda RBX: 00007fb8904ea490 RCX: 00007fb89034aa37
RDX: 00000000000003ff RSI: 00007fb8904ea490 RDI: 0000000000000002
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000206 R12: 00007fb8904ea490
R13: 00007fb8904c7dfe R14: 00007fb8904ea886 R15: 00007fb8904ea886
 </TASK>