INFO: task syz-executor:13586 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-executor state:D stack:20368 pid:13586 tgid:13586 ppid:1 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5352 [inline]
__schedule+0x1665/0x5590 kernel/sched/core.c:6964
__schedule_loop kernel/sched/core.c:7047 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7062
wb_wait_for_completion+0x3e8/0x790 fs/fs-writeback.c:227
sync_inodes_sb+0x1de/0xbd0 fs/fs-writeback.c:2924
sync_filesystem+0x17a/0x230 fs/sync.c:64
generic_shutdown_super+0x77/0x2d0 fs/super.c:625
kill_block_super+0x44/0x90 fs/super.c:1725
xfs_kill_sb+0x15/0x50 fs/xfs/xfs_super.c:2284
deactivate_locked_super+0xbc/0x130 fs/super.c:476
cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312
task_work_run+0x1d9/0x270 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3ac719d9d7
RSP: 002b:00007ffff2e5ee78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f3ac7232050 RCX: 00007f3ac719d9d7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffff2e5ef30
RBP: 00007ffff2e5ef30 R08: 00007ffff2e5ff30 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffff2e5ffc0
R13: 00007f3ac7232050 R14: 00000000000f9b0f R15: 00007ffff2e60000
Showing all locks held in the system:
3 locks held by kworker/1:0/24:
#0: ffff88801ee81548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x894/0x1780 kernel/workqueue.c:3261
#1: ffffc900001e7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1780 kernel/workqueue.c:3262
#2: ffff88802b10d198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:941 [inline]
#2: ffff88802b10d198 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899
1 lock held by khungtaskd/31:
#0: ffffffff8e75f420 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e75f420 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e75f420 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5589:
#0: ffff8880379220a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211
2 locks held by syz-executor/13586:
#0: ffff88807f0b40e0 (&type->s_umount_key#61){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88807f0b40e0 (&type->s_umount_key#61){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88807f0b40e0 (&type->s_umount_key#61){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508
#1: ffff888026d88820 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:396 [inline]
#1: ffff888026d88820 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x1c2/0xbd0 fs/fs-writeback.c:2922
4 locks held by kworker/u8:46/15080:
1 lock held by syz-executor/18659:
#0: ffffffff8e7656b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#0: ffffffff8e7656b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
2 locks held by syz.7.3318/19817:
#0: ffffffff9aefc098 (nfnl_subsys_ipset){+.+.}-{4:4}, at: call_ad+0x292/0xb60 net/netfilter/ipset/ip_set_core.c:1746
#1: ffffffff8e7656b8 (rcu_state.exp_mutex){+.+.}-{4:4}
, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961
=============================================
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 02/27/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:162 [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:353 [inline]
watchdog+0x1002/0x1060 kernel/hung_task.c:561
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
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: 15080 Comm: kworker/u8:46 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026
Workqueue: writeback wb_workfn (flush-7:6)
RIP: 0010:io_serial_out+0x7c/0xc0 drivers/tty/serial/8250/8250_port.c:407
Code: 51 83 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 cc af ec fc 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d e9 57 19 73 06 cc 44 89 f9 80 e1 07 38 c1
RSP: 0018:ffffc900051857b0 EFLAGS: 00000002
RAX: 0000000000000020 RBX: 0000000000000020 RCX: 0000000000000000
RDX: 00000000000003f8 RSI: 0000000000000000 RDI: 0000000000000020
RBP: 00000000000003f8 R08: ffff888026590237 R09: 1ffff11004cb2046
R10: dffffc0000000000 R11: ffffffff85435200 R12: dffffc0000000000
R13: ffffffff9a2d9950 R14: ffffffff9a5f1e80 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88812543d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff80d3e92f8 CR3: 00000000758d4000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000001800
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
serial_port_out include/linux/serial_core.h:811 [inline]
serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3192 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:-1 [inline]
serial8250_console_write+0x140c/0x1ba0 drivers/tty/serial/8250/8250_port.c:3342
console_emit_next_record kernel/printk/printk.c:3183 [inline]
console_flush_one_record kernel/printk/printk.c:3269 [inline]
console_flush_all+0x718/0xb20 kernel/printk/printk.c:3343
__console_flush_and_unlock kernel/printk/printk.c:3373 [inline]
console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3413
vprintk_emit+0x485/0x560 kernel/printk/printk.c:2479
_printk+0xdd/0x130 kernel/printk/printk.c:2504
print_hex_dump+0x1d2/0x2b0 lib/hexdump.c:286
xfs_hex_dump+0x3d/0x50 fs/xfs/xfs_message.c:110
xfs_buf_verifier_error+0x1cc/0x2a0 fs/xfs/xfs_error.c:330
xfs_allocbt_read_verify+0x5f/0xe0 fs/xfs/libxfs/xfs_alloc_btree.c:-1
__xfs_buf_ioend+0x332/0x710 fs/xfs/xfs_buf.c:1174
xfs_buf_iowait+0x167/0x4d0 fs/xfs/xfs_buf.c:1381
_xfs_buf_read fs/xfs/xfs_buf.c:643 [inline]
xfs_buf_read_map+0x324/0xa80 fs/xfs/xfs_buf.c:709
xfs_trans_read_buf_map+0x1db/0x950 fs/xfs/xfs_trans_buf.c:304
xfs_trans_read_buf fs/xfs/xfs_trans.h:212 [inline]
xfs_btree_read_buf_block+0x2b0/0x490 fs/xfs/libxfs/xfs_btree.c:1402
xfs_btree_lookup_get_block+0x297/0x510 fs/xfs/libxfs/xfs_btree.c:1907
xfs_btree_lookup+0x45a/0x1350 fs/xfs/libxfs/xfs_btree.c:2018
xfs_alloc_lookup fs/xfs/libxfs/xfs_alloc.c:166 [inline]
xfs_alloc_lookup_eq fs/xfs/libxfs/xfs_alloc.c:184 [inline]
xfs_alloc_fixup_trees+0x219/0xd30 fs/xfs/libxfs/xfs_alloc.c:626
xfs_alloc_cur_finish+0xd5/0x4d0 fs/xfs/libxfs/xfs_alloc.c:1117
xfs_alloc_ag_vextent_near+0xd63/0x12a0 fs/xfs/libxfs/xfs_alloc.c:1776
xfs_alloc_vextent_iterate_ags+0x66f/0x9a0 fs/xfs/libxfs/xfs_alloc.c:3764
xfs_alloc_vextent_start_ag+0x378/0x880 fs/xfs/libxfs/xfs_alloc.c:3839
xfs_bmap_btalloc_best_length fs/xfs/libxfs/xfs_bmap.c:3619 [inline]
xfs_bmap_btalloc fs/xfs/libxfs/xfs_bmap.c:3663 [inline]
xfs_bmapi_allocate+0x17c1/0x2da0 fs/xfs/libxfs/xfs_bmap.c:3938
xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4447 [inline]
xfs_bmapi_convert_delalloc+0x87a/0x1520 fs/xfs/libxfs/xfs_bmap.c:4503
xfs_map_blocks fs/xfs/xfs_aops.c:450 [inline]
xfs_writeback_range+0x69e/0xff0 fs/xfs/xfs_aops.c:494
iomap_writeback_range fs/iomap/buffered-io.c:1776 [inline]
iomap_writeback_folio+0x15f2/0x2770 fs/iomap/buffered-io.c:1895
iomap_writepages+0x167/0x2e0 fs/iomap/buffered-io.c:1958
xfs_vm_writepages+0x2fa/0x3e0 fs/xfs/xfs_aops.c:708
do_writepages+0x32e/0x550 mm/page-writeback.c:2554
__writeback_single_inode+0x133/0x11a0 fs/fs-writeback.c:1750
writeback_sb_inodes+0x992/0x1a20 fs/fs-writeback.c:2042
wb_writeback+0x456/0xb70 fs/fs-writeback.c:2227
wb_do_writeback fs/fs-writeback.c:2374 [inline]
wb_workfn+0x414/0xf50 fs/fs-writeback.c:2414
process_one_work+0x9ab/0x1780 kernel/workqueue.c:3289
process_scheduled_works kernel/workqueue.c:3380 [inline]
worker_thread+0xb49/0x1140 kernel/workqueue.c:3461
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245