INFO: task kworker/0:7:6341 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:7 state:D stack:22880 pid:6341 tgid:6341 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: xfs-sync/loop8 xfs_flush_inodes_worker
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
wb_wait_for_completion+0x360/0x680 fs/fs-writeback.c:226
sync_inodes_sb+0x1c9/0xb40 fs/fs-writeback.c:2894
xfs_flush_inodes_worker+0x61/0x80 fs/xfs/xfs_super.c:662
process_one_work+0x93a/0x15a0 kernel/workqueue.c:3279
process_scheduled_works kernel/workqueue.c:3362 [inline]
worker_thread+0x9b0/0xee0 kernel/workqueue.c:3443
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
INFO: task syz.8.46:6507 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.46 state:D stack:19096 pid:6507 tgid:6507 ppid:6082 task_flags:0x400640 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common kernel/sched/completion.c:121 [inline]
wait_for_common kernel/sched/completion.c:132 [inline]
wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153
__flush_work+0x9b9/0xbc0 kernel/workqueue.c:4331
xfs_file_buffered_write+0x266/0x8a0 fs/xfs/xfs_file.c:1000
__kernel_write_iter+0x428/0x910 fs/read_write.c:619
dump_emit_page fs/coredump.c:1298 [inline]
dump_user_range+0x8a0/0xc90 fs/coredump.c:1372
elf_core_dump+0x3369/0x3960 fs/binfmt_elf.c:2111
coredump_write+0x1121/0x18b0 fs/coredump.c:1049
do_coredump fs/coredump.c:1126 [inline]
vfs_coredump+0x3321/0x3e60 fs/coredump.c:1200
get_signal+0x1108/0x1340 kernel/signal.c:3019
arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop kernel/entry/common.c:75 [inline]
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline]
irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline]
irqentry_exit+0x177/0x660 kernel/entry/common.c:196
exc_page_fault+0xab/0x100 arch/x86/mm/fault.c:1535
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f9d3818f751
RSP: 002b:0000000000000050 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f9d383e6450 RCX: 00007f9d3818f749
RDX: 0000000000000000 RSI: 0000000000000050 RDI: 0000000000000000
RBP: 00007f9d38213f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9d383e64e8 R14: 00007f9d383e6450 R15: 00007fffa1e28e98
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8df41a60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8df41a60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8df41a60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
7 locks held by kworker/u8:12/3531:
2 locks held by getty/5581:
#0: ffff88814e75d0a0 (&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+0x449/0x1460 drivers/tty/n_tty.c:2211
4 locks held by kworker/0:7/6341:
#0: ffff88805618dd48 ((wq_completion)xfs-sync/loop8){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254
#1: ffffc9000216fb80 ((work_completion)(&mp->m_flush_inodes_work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255
#2: ffff88814d05c0e0 (&type->s_umount_key#66){++++}-{4:4}, at: xfs_flush_inodes_worker+0x45/0x80 fs/xfs/xfs_super.c:661
#3: ffff888024fe8820 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:397 [inline]
#3: ffff888024fe8820 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x1ad/0xb40 fs/fs-writeback.c:2892
2 locks held by syz.8.46/6507:
#0: ffff88814d05c420 (sb_writers#19){.+.+}-{0:0}, at: do_coredump fs/coredump.c:1126 [inline]
#0: ffff88814d05c420 (sb_writers#19){.+.+}-{0:0}, at: vfs_coredump+0x3321/0x3e60 fs/coredump.c:1200
#1: ffff8880486d64b0 (&sb->s_type->i_mutex_key#29){++++}-{4:4}, at: xfs_ilock+0xee/0x370 fs/xfs/xfs_inode.c:149
=============================================
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 10/25/2025
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]
__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:346 [inline]
watchdog+0xf95/0xfe0 kernel/hung_task.c:515
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 3531 Comm: kworker/u8:12 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: writeback wb_workfn (flush-7:8)
RIP: 0010:io_serial_out+0x7c/0xc0 drivers/tty/serial/8250/8250_port.c:407
Code: 55 a6 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 0c b8 0c fd 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d c3 cc cc cc cc cc 44 89 f9 80 e1 07 38 c1
RSP: 0018:ffffc9000c895ab0 EFLAGS: 00000002
RAX: 0000000000000037 RBX: 0000000000000037 RCX: 0000000000000000
RDX: 00000000000003f8 RSI: 0000000000000000 RDI: 0000000000000020
RBP: 00000000000003f8 R08: ffff888141790237 R09: 1ffff110282f2046
R10: dffffc0000000000 R11: ffffffff851b61a0 R12: dffffc0000000000
R13: ffffffff998e39ec R14: ffffffff99bf8280 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125e31000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa958bb7198 CR3: 0000000076a9e000 CR4: 00000000003526f0
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+0x1410/0x1ba0 drivers/tty/serial/8250/8250_port.c:3342
console_emit_next_record kernel/printk/printk.c:3129 [inline]
console_flush_one_record kernel/printk/printk.c:3215 [inline]
console_flush_all+0x745/0xb60 kernel/printk/printk.c:3289
__console_flush_and_unlock kernel/printk/printk.c:3319 [inline]
console_unlock+0xbb/0x190 kernel/printk/printk.c:3359
vprintk_emit+0x4f8/0x5f0 kernel/printk/printk.c:2426
_printk+0xcf/0x120 kernel/printk/printk.c:2451
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:310
xfs_agf_read_verify+0x16e/0x1f0 fs/xfs/libxfs/xfs_alloc.c:-1
__xfs_buf_ioend+0x332/0x6d0 fs/xfs/xfs_buf.c:1174
xfs_buf_iowait+0x143/0x440 fs/xfs/xfs_buf.c:1381
_xfs_buf_read fs/xfs/xfs_buf.c:643 [inline]
xfs_buf_read_map+0x325/0xa30 fs/xfs/xfs_buf.c:709
xfs_trans_read_buf_map+0x1d7/0x8a0 fs/xfs/xfs_trans_buf.c:304
xfs_trans_read_buf fs/xfs/xfs_trans.h:212 [inline]
xfs_read_agf+0x271/0x5a0 fs/xfs/libxfs/xfs_alloc.c:3376
xfs_alloc_read_agf+0x16f/0xb50 fs/xfs/libxfs/xfs_alloc.c:3411
xfs_bmap_longest_free_extent+0x77/0x150 fs/xfs/libxfs/xfs_bmap.c:3158
xfs_filestream_pick_ag fs/xfs/xfs_filestream.c:81 [inline]
xfs_filestream_create_association fs/xfs/xfs_filestream.c:297 [inline]
xfs_filestream_select_ag+0x80b/0x1ab0 fs/xfs/xfs_filestream.c:360
xfs_bmap_btalloc_filestreams fs/xfs/libxfs/xfs_bmap.c:3544 [inline]
xfs_bmap_btalloc fs/xfs/libxfs/xfs_bmap.c:3661 [inline]
xfs_bmapi_allocate+0x1651/0x2e00 fs/xfs/libxfs/xfs_bmap.c:3938
xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4447 [inline]
xfs_bmapi_convert_delalloc+0x7e2/0x1430 fs/xfs/libxfs/xfs_bmap.c:4503
xfs_map_blocks fs/xfs/xfs_aops.c:445 [inline]
xfs_writeback_range+0x674/0xf30 fs/xfs/xfs_aops.c:489
iomap_writeback_range fs/iomap/buffered-io.c:1724 [inline]
iomap_writeback_folio+0x1408/0x23f0 fs/iomap/buffered-io.c:1842
iomap_writepages+0x162/0x2d0 fs/iomap/buffered-io.c:1902
xfs_vm_writepages+0x296/0x310 fs/xfs/xfs_aops.c:701
do_writepages+0x32e/0x550 mm/page-writeback.c:2598
__writeback_single_inode+0x133/0x1240 fs/fs-writeback.c:1737
writeback_sb_inodes+0x93a/0x1870 fs/fs-writeback.c:2030
wb_writeback+0x42b/0xaa0 fs/fs-writeback.c:2216
wb_do_writeback fs/fs-writeback.c:2363 [inline]
wb_workfn+0x3f9/0xed0 fs/fs-writeback.c:2403
process_one_work+0x93a/0x15a0 kernel/workqueue.c:3279
process_scheduled_works kernel/workqueue.c:3362 [inline]
worker_thread+0x9b0/0xee0 kernel/workqueue.c:3443
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246