INFO: task kworker/0:6:5915 blocked for more than 144 seconds.
Not tainted 6.15.0-next-20250606-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:6 state:D stack:20064 pid:5915 tgid:5915 ppid:2 task_flags:0x4208060 flags:0x00004000
Workqueue: xfs-sync/loop4 xfs_flush_inodes_worker
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
__schedule_loop kernel/sched/core.c:6863 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6878
wb_wait_for_completion+0x15f/0x260 fs/fs-writeback.c:216
sync_inodes_sb+0x1bb/0xa10 fs/fs-writeback.c:2833
xfs_flush_inodes_worker+0x61/0x80 fs/xfs/xfs_super.c:652
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
INFO: task syz.4.1642:18605 blocked for more than 145 seconds.
Not tainted 6.15.0-next-20250606-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.1642 state:D
stack:22264 pid:18605 tgid:18604 ppid:17839 task_flags:0x400740 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
__schedule_loop kernel/sched/core.c:6863 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6878
schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:95 [inline]
__wait_for_common kernel/sched/completion.c:116 [inline]
wait_for_common kernel/sched/completion.c:127 [inline]
wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:148
__flush_work+0x9b9/0xbc0 kernel/workqueue.c:4246
xfs_file_buffered_write+0x25e/0x890 fs/xfs/xfs_file.c:1003
__kernel_write_iter+0x393/0x860 fs/read_write.c:619
dump_emit_page fs/coredump.c:1112 [inline]
dump_user_range+0x873/0xc70 fs/coredump.c:1186
elf_core_dump+0x32ed/0x3900 fs/binfmt_elf.c:2075
do_coredump+0x2806/0x3440 fs/coredump.c:950
get_signal+0x1109/0x1340 kernel/signal.c:3019
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:111
exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f668444f830
RSP: 002b:00007f6685318a78 EFLAGS: 00000246
ORIG_RAX: 0000000000000009
RAX: 0000000000000000 RBX: 00007f66847b5fa0 RCX: 00007f668458e929
RDX: 00007f6685318a80 RSI: 00007f6685318bb0 RDI: 000000000000000b
RBP: 00007f6684610b39 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000028011 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f66847b5fa0 R15: 00007ffd4c704398
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by getty/5601:
#0: ffff888034bc80a0 (
&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+0x43e/0x1400 drivers/tty/n_tty.c:2222
4 locks held by kworker/0:6/5915:
#0: ffff88807bfd6148 ((wq_completion)xfs-sync/loop4
){+.+.}-{0:0}
, at: process_one_work kernel/workqueue.c:3213 [inline]
, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
#1:
ffffc9000487fbc0
((work_completion)(&mp->m_flush_inodes_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
((work_completion)(&mp->m_flush_inodes_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
#2: ffff88806b30e0e0 (&type->s_umount_key#61){++++}-{4:4}, at: xfs_flush_inodes_worker+0x45/0x80 fs/xfs/xfs_super.c:651
#3: ffff8881433167d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
#3: ffff8881433167d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831
6 locks held by kworker/u8:11/6204:
2 locks held by syz.4.1642/18605:
#0:
ffff88806b30e428
(
sb_writers
#30
){++++}-{0:0}, at: do_coredump+0x27cb/0x3440 fs/coredump.c:949
#1:
ffff8880488331b0 (&sb->s_type->i_mutex_key#34){++++}-{4:4}, at: xfs_ilock+0xfe/0x390 fs/xfs/xfs_inode.c:149
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-next-20250606-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:470
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6204 Comm: kworker/u8:11 Not tainted 6.15.0-next-20250606-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: writeback wb_workfn (flush-7:4)
RIP: 0010:io_serial_out+0x7c/0xc0 drivers/tty/serial/8250/8250_port.c:416
Code: 93 78 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 fc 0a dc fc 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d e9 07 ce 21 06 cc 44 89 f9 80 e1 07 38 c1
RSP: 0018:ffffc900058358f0 EFLAGS: 00000002
RAX: 0000000000000037 RBX: 0000000000000037 RCX: 0000000000000000
RDX: 00000000000003f8 RSI: 0000000000000000 RDI: 0000000000000020
RBP: 00000000000003f8 R08: ffff888024928237 R09: 1ffff11004925046
R10: dffffc0000000000 R11: ffffffff8547cb50 R12: dffffc0000000000
R13: ffffffff99ac88c6 R14: ffffffff99dcd740 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125d4d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc601b80ab8 CR3: 000000007f0e8000 CR4: 00000000003526f0
Call Trace:
serial_port_out include/linux/serial_core.h:798 [inline]
serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3306 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:-1 [inline]
serial8250_console_write+0x1410/0x1ba0 drivers/tty/serial/8250/8250_port.c:3456
console_emit_next_record kernel/printk/printk.c:3138 [inline]
console_flush_all+0x725/0xc40 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
_printk+0xcf/0x120 kernel/printk/printk.c:2475
print_hex_dump+0x1a8/0x260 lib/hexdump.c:285
xfs_hex_dump+0x3d/0x50 fs/xfs/xfs_message.c:110
xfs_buf_verifier_error+0x1cc/0x2a0 fs/xfs/xfs_error.c:466
xfs_agfl_read_verify+0x165/0x1f0 fs/xfs/libxfs/xfs_alloc.c:-1
__xfs_buf_ioend+0x33f/0x6f0 fs/xfs/xfs_buf.c:1177
xfs_buf_iowait+0x167/0x480 fs/xfs/xfs_buf.c:1384
_xfs_buf_read fs/xfs/xfs_buf.c:646 [inline]
xfs_buf_read_map+0x335/0xa50 fs/xfs/xfs_buf.c:712
xfs_trans_read_buf_map+0x1d7/0x8e0 fs/xfs/xfs_trans_buf.c:304
xfs_trans_read_buf fs/xfs/xfs_trans.h:212 [inline]
xfs_alloc_read_agfl+0x202/0x410 fs/xfs/libxfs/xfs_alloc.c:885
xfs_alloc_fix_freelist+0xb93/0x1300 fs/xfs/libxfs/xfs_alloc.c:2961
xfs_alloc_vextent_prepare_ag+0xdb/0x610 fs/xfs/libxfs/xfs_alloc.c:3541
xfs_alloc_vextent_iterate_ags+0x140/0x940 fs/xfs/libxfs/xfs_alloc.c:3725
xfs_alloc_vextent_start_ag+0x388/0x850 fs/xfs/libxfs/xfs_alloc.c:3814
xfs_bmap_btalloc_best_length fs/xfs/libxfs/xfs_bmap.c:3627 [inline]
xfs_bmap_btalloc fs/xfs/libxfs/xfs_bmap.c:3672 [inline]
xfs_bmapi_allocate+0x188e/0x2e00 fs/xfs/libxfs/xfs_bmap.c:3947
xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4456 [inline]
xfs_bmapi_convert_delalloc+0x7e2/0x1430 fs/xfs/libxfs/xfs_bmap.c:4512
xfs_map_blocks+0x667/0xe80 fs/xfs/xfs_aops.c:405
iomap_writepage_map_blocks fs/iomap/buffered-io.c:1773 [inline]
iomap_writepage_map fs/iomap/buffered-io.c:1923 [inline]
iomap_writepages+0x10df/0x3240 fs/iomap/buffered-io.c:1977
xfs_vm_writepages+0x235/0x2b0 fs/xfs/xfs_aops.c:650
do_writepages+0x32b/0x550 mm/page-writeback.c:2636
__writeback_single_inode+0x145/0xff0 fs/fs-writeback.c:1680
writeback_sb_inodes+0x6b5/0x1000 fs/fs-writeback.c:1976
wb_writeback+0x43b/0xaf0 fs/fs-writeback.c:2156
wb_do_writeback fs/fs-writeback.c:2303 [inline]
wb_workfn+0x409/0xef0 fs/fs-writeback.c:2343
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245