INFO: task syz.0.1710:12549 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.0.1710 state:D stack:25128 pid:12549 tgid:12548 ppid:5822 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
__schedule_loop kernel/sched/core.c:6948 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6963
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7020
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776
bdev_open+0xe0/0xd30 block/bdev.c:962
bdev_file_open_by_dev+0x1be/0x240 block/bdev.c:1076
setup_bdev_super+0x5a/0x5b0 fs/super.c:1609
get_tree_bdev_flags+0x366/0x4d0 fs/super.c:1689
vfs_get_tree+0x92/0x2a0 fs/super.c:1751
fc_mount fs/namespace.c:1199 [inline]
do_new_mount_fc fs/namespace.c:3636 [inline]
do_new_mount+0x302/0xa10 fs/namespace.c:3712
do_mount fs/namespace.c:4035 [inline]
__do_sys_mount fs/namespace.c:4224 [inline]
__se_sys_mount+0x313/0x410 fs/namespace.c:4201
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff39538f749
RSP: 002b:00007ff396284038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ff3955e5fa0 RCX: 00007ff39538f749
RDX: 0000200000000100 RSI: 0000200000000a80 RDI: 0000200000000040
RBP: 00007ff395413f91 R08: 0000200000000140 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff3955e6038 R14: 00007ff3955e5fa0 R15: 00007ffe326d0428
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e33f2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e33f2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e33f2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
1 lock held by klogd/5189:
3 locks held by kworker/0:7/5906:
#0: ffff88813fe55948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254
#1: ffffc9000519fb80 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255
#2: ffffffff8e344e38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#2: ffffffff8e344e38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:956
3 locks held by kworker/1:7/5913:
#0: ffff8880212e1d48 ((wq_completion)infiniband){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254
#1: ffffc900051e7b80 ((work_completion)(&work->work)#3){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255
#2: ffffffff8f72c588 (rtnl_mutex){+.+.}-{4:4}, at: ib_get_eth_speed+0x151/0x7c0 drivers/infiniband/core/verbs.c:1998
1 lock held by udevd/6904:
#0: ffff8881427db358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:962
3 locks held by kworker/u8:15/7252:
#0: ffff88813fe69948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254
#1: ffffc90003e6fb80 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255
#2: ffffffff8f72c588 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
2 locks held by syz.6.836/9341:
#0: ffffffff8f72c588 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8f72c588 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436
#1: ffffffff8e344e38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#1: ffffffff8e344e38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:956
2 locks held by getty/9630:
#0: ffff88814ddf20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003d072f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460 drivers/tty/n_tty.c:2211
2 locks held by syz.0.1710/12549:
#0: ffff88802996e0e0 (&type->s_umount_key#65/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xaa0 fs/super.c:344
#1: ffff8881427db358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:962
1 lock held by syz.4.1994/13688:
1 lock held by syz.7.2406/14964:
#0: ffffffff8f72c588 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8f72c588 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436
4 locks held by syz-executor/15079:
#0: ffff88801db00ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:499 [inline]
#0: ffff88801db00ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x5b0 net/bluetooth/hci_core.c:2715
#1: ffff88801db000c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x1100 net/bluetooth/hci_sync.c:5329
#2: ffffffff8f89e048 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2151 [inline]
#2: ffffffff8f89e048 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x260 net/bluetooth/hci_conn.c:2643
#3: ffff88803455b338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7b/0x5b0 net/bluetooth/l2cap_core.c:1763
=============================================
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 10/25/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [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:363 [inline]
watchdog+0xe40/0xe90 kernel/hung_task.c:557
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 60 Comm: kworker/u8:4 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: ib-unreg-wq ib_unregister_work
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:400
Code: e8 6e 91 9c 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 cf 39 03 fd 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 cc cc cc cc cc 44 89 f9 80 e1 07
RSP: 0018:ffffc9000211f3d0 EFLAGS: 00000002
RAX: 1ffffffff3409c00 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020
RBP: ffffffff9a04e710 R08: ffff888141b00237 R09: 1ffff11028360046
R10: dffffc0000000000 R11: ffffffff852566a0 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff9a04e480 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881259dc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d858299168 CR3: 000000002f30a000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff4ff0 DR7: 0000000000000400
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:128 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline]
wait_for_lsr+0x1a1/0x2f0 drivers/tty/serial/8250/8250_port.c:1961
fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3234 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3257 [inline]
serial8250_console_write+0x134c/0x1ba0 drivers/tty/serial/8250/8250_port.c:3342
console_emit_next_record kernel/printk/printk.c:3129 [inline]
console_flush_one_record kernel/printk/printk.c:3215 [inline]
console_flush_all+0x745/0xb60 kernel/printk/printk.c:3289
__console_flush_and_unlock kernel/printk/printk.c:3319 [inline]
console_unlock+0xbb/0x190 kernel/printk/printk.c:3359
vprintk_emit+0x4f8/0x5f0 kernel/printk/printk.c:2426
_printk+0xcf/0x120 kernel/printk/printk.c:2451
ib_unregister_work+0x25/0x50 drivers/infiniband/core/device.c:1694
process_one_work+0x93a/0x15a0 kernel/workqueue.c:3279
process_scheduled_works kernel/workqueue.c:3362 [inline]
worker_thread+0x9b0/0xee0 kernel/workqueue.c:3443
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246