INFO: task syz-executor:10954 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:21832 pid:10954 tgid:10954 ppid:1 task_flags:0x400140 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
netfs_wait_for_outstanding_io include/linux/netfs.h:552 [inline]
v9fs_evict_inode+0x170/0x320 fs/9p/vfs_inode.c:348
evict+0x504/0x9c0 fs/inode.c:810
__dentry_kill+0x209/0x660 fs/dcache.c:669
dput+0x19f/0x2b0 fs/dcache.c:911
shrink_dcache_for_umount+0xa0/0x170 fs/dcache.c:1621
generic_shutdown_super+0x67/0x2c0 fs/super.c:621
kill_anon_super+0x3b/0x70 fs/super.c:1282
v9fs_kill_super+0x4c/0x90 fs/9p/vfs_super.c:195
deactivate_locked_super+0xbc/0x130 fs/super.c:474
cleanup_mnt+0x425/0x4c0 fs/namespace.c:1375
task_work_run+0x1d4/0x260 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb358f901f7
RSP: 002b:00007ffcb191dca8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fb359011d7d RCX: 00007fb358f901f7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffcb191dd60
RBP: 00007ffcb191dd60 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffcb191edf0
R13: 00007fb359011d7d R14: 00000000000c59df R15: 00007ffcb191ee30
Showing all locks held in the system:
2 locks held by ksoftirqd/0/15:
1 lock held by khungtaskd/31:
#0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:5/61:
1 lock held by udevd/5228:
#0: ffff8880256b6358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945
2 locks held by getty/5617:
#0: ffff888033c740a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000362b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by syz-executor/10935:
#0: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#0: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957
1 lock held by syz-executor/10954:
#0: ffff888078faa0e0 (&type->s_umount_key#98){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff888078faa0e0 (&type->s_umount_key#98){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff888078faa0e0 (&type->s_umount_key#98){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
1 lock held by syz-executor/11261:
#0: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#0: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957
1 lock held by udevd/11451:
#0: ffff8880256b6358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945
3 locks held by kworker/u8:34/11703:
5 locks held by kworker/u8:40/11709:
#0: ffff8880b8639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:644
#1: ffff8880b8624008 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
#2: ffff88805fcd0768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6212 [inline]
#2: ffff88805fcd0768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: cfg80211_wiphy_work+0xc4/0x470 net/wireless/core.c:421
#3: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#3: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#3: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: ieee80211_sta_active_ibss+0xc3/0x330 net/mac80211/ibss.c:635
#4: ffffffff99d240a8 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0xbb/0x420 lib/debugobjects.c:818
1 lock held by syz.1.1289/12721:
#0: ffff8880256b6358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1a9/0x650 block/bdev.c:1128
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
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]
check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
watchdog+0xf93/0xfe0 kernel/hung_task.c:491
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 93 Comm: kworker/0:1H Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: kblockd blk_mq_timeout_work
RIP: 0010:io_serial_out+0x7c/0xc0 drivers/tty/serial/8250/8250_port.c:407
Code: fe 6f fc 44 89 f9 d3 e5 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 4c 7c d3 fc 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d e9 22 92 c0 fb cc 44 89 f9 80 e1 07 38 c1
RSP: 0018:ffffc9000211ecd0 EFLAGS: 00000006
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 00000000000003f9 RSI: 0000000000000000 RDI: 0000000000000020
RBP: 00000000000003f9 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: ffffffff854fae60 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffffffff99df8460 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125c12000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555556ec5608 CR3: 00000000749ba000 CR4: 0000000000350ef0
Call Trace:
serial_out drivers/tty/serial/8250/8250.h:142 [inline]
serial8250_clear_IER drivers/tty/serial/8250/8250_port.c:-1 [inline]
serial8250_console_write+0x5f2/0x1ba0 drivers/tty/serial/8250/8250_port.c:3361
console_emit_next_record kernel/printk/printk.c:3138 [inline]
console_flush_all+0x728/0xc40 kernel/printk/printk.c:3226
__console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
console_unlock+0xc4/0x270 kernel/printk/printk.c:3325
vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450
dev_vprintk_emit+0x337/0x3f0 drivers/base/core.c:4914
dev_printk_emit+0xe0/0x130 drivers/base/core.c:4925
_dev_info+0x10a/0x160 drivers/base/core.c:4983
nbd_xmit_timeout+0x832/0xb30 drivers/block/nbd.c:520
blk_mq_rq_timed_out block/blk-mq.c:1635 [inline]
blk_mq_handle_expired+0x172/0x2c0 block/blk-mq.c:1703
bt_iter+0x2f3/0x3c0 block/blk-mq-tag.c:292
__sbitmap_for_each_set include/linux/sbitmap.h:269 [inline]
sbitmap_for_each_set+0x301/0x5e0 include/linux/sbitmap.h:290
bt_for_each block/blk-mq-tag.c:324 [inline]
blk_mq_queue_tag_busy_iter+0x43b/0x770 block/blk-mq-tag.c:533
blk_mq_timeout_work+0x1d6/0x3e0 block/blk-mq.c:1745
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245