INFO: task syz-executor:4277 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:21792 pid:4277 ppid:1 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
schedule+0xb9/0x180 kernel/sched/core.c:6637
wb_wait_for_completion+0x162/0x280 fs/fs-writeback.c:191
sync_inodes_sb+0x1b8/0x9e0 fs/fs-writeback.c:2750
sync_filesystem+0x16d/0x220 fs/sync.c:64
generic_shutdown_super+0x6b/0x340 fs/super.c:474
kill_block_super+0x7c/0xe0 fs/super.c:1470
deactivate_locked_super+0x93/0xf0 fs/super.c:332
cleanup_mnt+0x463/0x4f0 fs/namespace.c:1191
task_work_run+0x1ca/0x250 kernel/task_work.c:203
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7faa6a190a77
RSP: 002b:00007ffebb7af048 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007faa6a213d7d RCX: 00007faa6a190a77
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffebb7af100
RBP: 00007ffebb7af100 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffebb7b0190
R13: 00007faa6a213d7d R14: 000000000003db80 R15: 00007ffebb7b01d0
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8cb2b630 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8cb2be50
(
rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
2 locks held by kworker/0:1/14:
#0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1:
ffffc90000137d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
2 locks held by kworker/1:0/22:
1 lock held by khungtaskd/28:
#0:
ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
4 locks held by kworker/u4:3/46:
#0: ffff888017616938
(
(wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1:
ffffc90000b77d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2: ffffffff8dd34a10 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:594
#3: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: wiphy_unregister+0x22c/0xb00 net/wireless/core.c:1091
2 locks held by kworker/u4:4/48:
#0: ffff88814464e938
(
(wq_completion)writeback
){+.+.}-{0:0}
, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1:
ffffc90000b97d00
((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
1 lock held by dhcpcd/3932:
#0: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x288/0x1af0 net/ipv4/devinet.c:1080
2 locks held by getty/4026:
#0: ffff88814da8e098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198
2 locks held by syz-executor/4264:
#0: ffff88807b6c20e0 (&type->s_umount_key
#59
){+.+.}-{3:3}
, at: deactivate_super+0xa0/0xd0 fs/super.c:362
#1:
ffff8880241e67d0
(&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
(&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x19c/0x9e0 fs/fs-writeback.c:2748
2 locks held by syz-executor/4277:
#0: ffff88807389a0e0 (&type->s_umount_key#59){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362
#1: ffff8881443bc7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
#1: ffff8881443bc7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x19c/0x9e0 fs/fs-writeback.c:2748
5 locks held by kworker/0:12/4494:
#0:
ffff8880b8e3aad8
(
&rq->__lock
){-.-.}-{2:2}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc900052afd00 ((work_completion)(&bp->b_ioend_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2: ffffffff8cb1ef40 (console_lock){+.+.}-{0:0}, at: raw_spin_rq_lock_nested+0xa5/0x140 kernel/sched/core.c:545
#3: ffffffff8cb1ee60 (console_owner){-.-.}-{0:0}, at: console_lock_spinning_enable kernel/printk/printk.c:1818 [inline]
#3: ffffffff8cb1ee60 (console_owner){-.-.}-{0:0}, at: console_emit_next_record+0x82d/0xc90 kernel/printk/printk.c:2774
#4: ffff8880b8e3aad8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa5/0x140 kernel/sched/core.c:545
3 locks held by kworker/1:12/4625:
#0: ffff88802e7a3538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc900054a7d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x14d0 net/ipv6/addrconf.c:4131
3 locks held by kworker/0:16/5095:
#0: ffff88802e7a3538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc9000e65fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x14d0 net/ipv6/addrconf.c:4131
4 locks held by kworker/u4:9/8257:
#0: ffff88814464e938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc900033c7d00 ((work_completion)(&(&wb->dwork)->work)
){+.+.}-{0:0}
, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2: ffff88807b6c2650 (sb_internal#2){.+.+}-{0:0}, at: xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4571 [inline]
#2: ffff88807b6c2650 (sb_internal#2){.+.+}-{0:0}, at: xfs_bmapi_convert_delalloc+0x2fd/0x1480 fs/xfs/libxfs/xfs_bmap.c:4698
#3: ffff888054423f18 (&xfs_nondir_ilock_class){++++}-{3:3}, at: xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4576 [inline]
#3: ffff888054423f18 (&xfs_nondir_ilock_class){++++}-{3:3}, at: xfs_bmapi_convert_delalloc+0x329/0x1480 fs/xfs/libxfs/xfs_bmap.c:4698
1 lock held by syz-executor/9324:
#0: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
#0: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147
1 lock held by syz-executor/9328:
#0: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
#0: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147
7 locks held by syz-executor/9387:
#0: ffff88807e300460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x256/0x960 fs/read_write.c:580
#1: ffff88807cf45488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e3/0x520 fs/kernfs/file.c:343
#2: ffff888145b4b748 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888145b4b748 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8d64cac8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xce/0x360 drivers/net/netdevsim/bus.c:209
#4: ffff888054e980e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:840 [inline]
#4: ffff888054e980e8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1080 [inline]
#4: ffff888054e980e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb2/0x850 drivers/base/dd.c:1283
#5: ffff888054e9d2f8 (&devlink->lock_key#7){+.+.}-{3:3}, at: nsim_drv_remove+0x54/0x160 drivers/net/netdevsim/dev.c:1677
#6: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: nsim_destroy+0x3b/0x150 drivers/net/netdevsim/netdev.c:381
1 lock held by syz-executor/9456:
#0: ffffffff8dd416e8
(rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
(rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147
1 lock held by syz.4.1771/9613:
#0: ffffffff8cb30978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
#0: ffffffff8cb30978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x346/0x830 kernel/rcu/tree_exp.h:962
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xeee/0xf30 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4621 Comm: kworker/1:8 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: xfs-buf/loop2 xfs_buf_ioend_work
RIP: 0010:io_serial_out+0x78/0xb0 drivers/tty/serial/8250/8250_port.c:468
Code: 78 09 fd 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 30 a7 59 fd 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d c3 44 89 f9 80 e1 07 38 c1 7c aa 4c 89 ff
RSP: 0018:ffffc90005e572f0 EFLAGS: 00000002
RAX: 000000000000005b RBX: 000000000000005b RCX: 0000000000000000
RDX: 00000000000003f8 RSI: 0000000000000000 RDI: 0000000000000020
RBP: 00000000000003f8 R08: dffffc0000000000 R09: ffffed10047ba047
R10: ffffed10047ba047 R11: 1ffff110047ba046 R12: dffffc0000000000
R13: ffffffff96c2be01 R14: ffffffff96f704c0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f0d1eeda38 CR3: 000000000c88e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
serial_out drivers/tty/serial/8250/8250.h:122 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:-1 [inline]
serial8250_console_write+0x10fa/0x17a0 drivers/tty/serial/8250/8250_port.c:3473
call_console_driver kernel/printk/printk.c:1977 [inline]
console_emit_next_record+0x947/0xc90 kernel/printk/printk.c:2777
console_flush_all kernel/printk/printk.c:-1 [inline]
console_unlock+0x223/0x630 kernel/printk/printk.c:2906
vprintk_emit+0x489/0x680 kernel/printk/printk.c:2303
_printk+0xcc/0x110 kernel/printk/printk.c:2328
print_hex_dump+0x1a5/0x260 lib/hexdump.c:285
xfs_hex_dump+0x39/0x50 fs/xfs/xfs_message.c:110
xfs_buf_verifier_error+0x1c8/0x290 fs/xfs/xfs_error.c:441
xfs_allocbt_read_verify+0x53/0xd0 fs/xfs/libxfs/xfs_alloc_btree.c:-1
xfs_buf_ioend+0x27a/0x780 fs/xfs/xfs_buf.c:1303
process_one_work+0x898/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295