INFO: task syz-executor:5828 blocked for more than 143 seconds.
Not tainted 6.14.0-syzkaller-01103-g2df0c02dab82 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:14416 pid:5828 tgid:5828 ppid:1 task_flags:0x400140 flags:0x00000004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5367 [inline]
__schedule+0x1ac3/0x5090 kernel/sched/core.c:6748
__schedule_loop kernel/sched/core.c:6825 [inline]
schedule+0x163/0x360 kernel/sched/core.c:6840
wait_on_inode+0x14d/0x230 include/linux/writeback.h:206
iget5_locked_rcu+0xc7/0x1c0 fs/inode.c:1391
btrfs_iget_locked fs/btrfs/inode.c:5614 [inline]
btrfs_iget+0x169/0x2b0 fs/btrfs/inode.c:5654
btrfs_lookup_dentry+0x45b/0x16e0 fs/btrfs/inode.c:5743
btrfs_lookup+0x1d/0x40 fs/btrfs/inode.c:5808
__lookup_slow+0x2b1/0x400 fs/namei.c:1807
lookup_slow+0x53/0x70 fs/namei.c:1824
walk_component+0x2f4/0x420 fs/namei.c:2128
lookup_last fs/namei.c:2626 [inline]
path_lookupat+0x169/0x440 fs/namei.c:2650
filename_lookup+0x290/0x670 fs/namei.c:2679
user_path_at+0x3a/0x60 fs/namei.c:3085
ksys_umount fs/namespace.c:2162 [inline]
__do_sys_umount fs/namespace.c:2170 [inline]
__se_sys_umount fs/namespace.c:2168 [inline]
__x64_sys_umount+0xf0/0x170 fs/namespace.c:2168
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb01338e497
RSP: 002b:00007fff81c930a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb01338e497
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff81c93160
RBP: 00007fff81c93160 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff81c94250
R13: 00007fb01340e08c R14: 0000000000029652 R15: 00007fff81c95320
</TASK>
Showing all locks held in the system:
6 locks held by kworker/u8:0/12:
1 lock held by khungtaskd/31:
#0: ffffffff8eb3a760 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8eb3a760 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8eb3a760 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x30/0x180 kernel/locking/lockdep.c:6761
3 locks held by kworker/u8:3/59:
#0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319
#1: ffffc9000103fc60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc9000103fc60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319
#2: ffffffff8fec3e48 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:285
1 lock held by dhcpcd/5491:
#0: ffffffff8fec3e48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:129 [inline]
#0: ffffffff8fec3e48 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_deladdr+0x292/0x3a0 net/ipv6/addrconf.c:4795
2 locks held by getty/5581:
#0: ffff8880362f90a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90002fd62f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x53d/0x16b0 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/5822:
#0: ffffffff8eb3fc78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline]
#0: ffffffff8eb3fc78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x454/0x830 kernel/rcu/tree_exp.h:998
1 lock held by syz-executor/5828:
#0: ffff888055981ee0 (&type->i_mutex_dir_key#10){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:877 [inline]
#0: ffff888055981ee0 (&type->i_mutex_dir_key#10){++++}-{4:4}, at: lookup_slow+0x45/0x70 fs/namei.c:1823
5 locks held by kworker/u8:8/9421:
#0: ffff88801baf3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801baf3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319
#1: ffffc9000364fc60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc9000364fc60 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319
#2: ffffffff8feb7610 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x17c/0xd60 net/core/net_namespace.c:606
#3: ffffffff8fec3e48 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xde/0x880 net/core/dev.c:12420
#4: ffffffff8eb3fc78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline]
#4: ffffffff8eb3fc78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x384/0x830 kernel/rcu/tree_exp.h:998
1 lock held by syz-executor/12629:
#0: ffffffff8fec3e48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
#0: ffffffff8fec3e48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:335 [inline]
#0: ffffffff8fec3e48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xd6a/0x1f60 net/core/rtnetlink.c:4021
2 locks held by syz.8.744/12950:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.14.0-syzkaller-01103-g2df0c02dab82 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
nmi_cpu_backtrace+0x4ab/0x4e0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline]
watchdog+0x1058/0x10a0 kernel/hung_task.c:399
kthread+0x7a9/0x920 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
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: 5822 Comm: syz-executor Not tainted 6.14.0-syzkaller-01103-g2df0c02dab82 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:io_serial_in+0x76/0xb0 drivers/tty/serial/8250/8250_port.c:409
Code: 60 63 3f fc 89 e9 41 d3 e6 48 83 c3 40 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 61 f4 a4 fc 44 03 33 44 89 f2 ec <0f> b6 c0 5b 41 5e 41 5f 5d c3 cc cc cc cc 89 e9 80 e1 07 38 c1 7c
RSP: 0018:ffffc90004167438 EFLAGS: 00000002
RAX: 1ffffffff34f7e00 RBX: ffffffff9a7bf300 RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020
RBP: 0000000000000000 R08: ffffffff8583eec6 R09: 1ffff11004a39046
R10: dffffc0000000000 R11: ffffffff8583ee80 R12: 0000000000000020
R13: 1ffffffff34f7eb2 R14: 00000000000003fd R15: dffffc0000000000
FS: 000055557867a500(0000) GS:ffff88812525a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555786955c8 CR3: 000000007a80e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<NMI>
</NMI>
<TASK>
serial_in drivers/tty/serial/8250/8250.h:137 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:159 [inline]
wait_for_lsr+0x1b1/0x320 drivers/tty/serial/8250/8250_port.c:2100
fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3357 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3380 [inline]
serial8250_console_write+0x1350/0x1e00 drivers/tty/serial/8250/8250_port.c:3465
console_emit_next_record kernel/printk/printk.c:3120 [inline]
console_flush_all+0x86b/0xec0 kernel/printk/printk.c:3208
__console_flush_and_unlock kernel/printk/printk.c:3267 [inline]
console_unlock+0x151/0x3b0 kernel/printk/printk.c:3307
vprintk_emit+0x732/0xa10 kernel/printk/printk.c:2432
_printk+0xd5/0x120 kernel/printk/printk.c:2457
_btrfs_printk+0x5d1/0x620 fs/btrfs/messages.c:248
btrfs_put_super+0x69/0x80 fs/btrfs/super.c:73
generic_shutdown_super+0x139/0x2d0 fs/super.c:642
kill_anon_super+0x3b/0x70 fs/super.c:1237
btrfs_kill_super+0x41/0x50 fs/btrfs/super.c:2100
deactivate_locked_super+0xc4/0x130 fs/super.c:473
cleanup_mnt+0x422/0x4c0 fs/namespace.c:1435
task_work_run+0x251/0x310 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x13f/0x340 kernel/entry/common.c:218
do_syscall_64+0x100/0x230 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7faba918e497
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffc72c37988 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007faba918e497
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc72c37a40
RBP: 00007ffc72c37a40 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc72c38ad0
R13: 00007faba920e08c R14: 000000000004dc5c R15: 00007ffc72c38b10
</TASK>