INFO: task kworker/0:4:5963 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:4 state:D stack:20712 pid:5963 tgid:5963 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: xfs-sync/loop0 xfs_flush_inodes_worker
Call Trace:
context_switch kernel/sched/core.c:5360 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6964
__schedule_loop kernel/sched/core.c:7046 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7061
wb_wait_for_completion+0x15f/0x260 fs/fs-writeback.c:216
sync_inodes_sb+0x1bb/0xa10 fs/fs-writeback.c:2873
xfs_flush_inodes_worker+0x61/0x80 fs/xfs/xfs_super.c:648
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
INFO: task syz.0.2291:17987 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.2291 state:D stack:21224 pid:17987 tgid:17985 ppid:12265 task_flags:0x400740 flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5360 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6964
__schedule_loop kernel/sched/core.c:7046 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7061
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:4273
xfs_file_buffered_write+0x266/0x8a0 fs/xfs/xfs_file.c:997
__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+0x116c/0x1900 fs/coredump.c:1049
vfs_coredump+0x1db5/0x2a60 fs/coredump.c:1170
get_signal+0x1108/0x1340 kernel/signal.c:3019
arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x72/0x130 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f557af8eec9
RSP: 002b:00007f557be520e8 EFLAGS: 00000246
ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f557b1e5fa8 RCX: 00007f557af8eec9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f557b1e5fac
RBP: 00007f557b1e5fa0 R08: 7fffffffffffffff R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f557b1e6038 R14: 00007ffcef38e860 R15: 00007ffcef38e948
Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
#0:
ffffffff8e342df8
(
rcu_state.exp_mutex
){+.+.}-{4:4}
, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957
1 lock held by khungtaskd/31:
#0: ffffffff8e33d360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e33d360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e33d360 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5627:
#0:
ffff888030c300a0
(
&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
4 locks held by kworker/0:4/5963:
#0: ffff8880514f4948 ((wq_completion)xfs-sync/loop0){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff8880514f4948 ((wq_completion)xfs-sync/loop0){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc900044cfba0 ((work_completion)(&mp->m_flush_inodes_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc900044cfba0 ((work_completion)(&mp->m_flush_inodes_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffff88807bb220e0 (&type->s_umount_key#93){++++}-{4:4}, at: xfs_flush_inodes_worker+0x45/0x80 fs/xfs/xfs_super.c:647
#3: ffff888051db2820 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
#3: ffff888051db2820 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2871
2 locks held by kworker/u8:10/6216:
#0: ffff8880203aa148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff8880203aa148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc9000b007ba0 (
(work_completion)(&ctx->exit_work)
){+.+.}-{0:0}
, at: process_one_work kernel/workqueue.c:3239 [inline]
, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
9 locks held by kworker/u8:8/9855:
2 locks held by syz.0.2291/17987:
#0:
ffff88807bb22420
(
sb_writers#32){.+.+}-{0:0}, at: vfs_coredump+0x1db5/0x2a60 fs/coredump.c:1170
#1:
ffff88804dd33f30
(&sb->s_type->i_mutex_key#40){++++}-{4:4}, at: xfs_ilock+0xfe/0x390 fs/xfs/xfs_inode.c:149
1 lock held by syz.2.2605/19344:
#0:
ffffffff8e342cc0
(
rcu_state.barrier_mutex
){+.+.}-{4:4}
, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3820
=============================================
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 08/18/2025
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]
check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
watchdog+0xf60/0xfa0 kernel/hung_task.c:495
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 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: 9855 Comm: kworker/u8:8 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: writeback wb_workfn (flush-7:0)
RIP: 0010:vsnprintf+0x34f/0xf00 lib/vsprintf.c:2876
Code: 0f b6 04 18 84 c0 0f 85 ba 09 00 00 41 c6 45 00 25 e9 7a 04 00 00 48 89 eb 4c 29 fb 4c 63 e3 4c 3b 6c 24 20 0f 83 e3 01 00 00 2c 19 46 f6 4c 89 74 24 08 4c 8b 74 24 20 4d 29 ee 4c 89 e7 4c
RSP: 0018:ffffc9000b405570 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000001
RDX: ffffffff8b7a3b68 RSI: ffffffff8faa4100 RDI: 0000000000000000
RBP: ffffffff8bab9201 R08: ffff8880309f9e40 R09: 0000000000000008
R10: 0000000000000007 R11: 0000000000000000 R12: 0000000000000001
R13: ffffc9000b405840 R14: 0000000000000000 R15: ffffffff8bab9200
FS: 0000000000000000(0000) GS:ffff888125a03000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe4eb7af88 CR3: 00000000421a2000 CR4: 00000000003526f0
Call Trace:
sprintf+0xd9/0x120 lib/vsprintf.c:3089
print_time kernel/printk/printk.c:1354 [inline]
info_print_prefix+0x155/0x310 kernel/printk/printk.c:1380
record_print_text+0x154/0x420 kernel/printk/printk.c:1429
printk_get_next_message+0x26d/0x7b0 kernel/printk/printk.c:2997
console_emit_next_record kernel/printk/printk.c:3065 [inline]
console_flush_all+0x4ca/0xb10 kernel/printk/printk.c:3199
__console_flush_and_unlock kernel/printk/printk.c:3258 [inline]
console_unlock+0xbb/0x190 kernel/printk/printk.c:3298
vprintk_emit+0x4c5/0x590 kernel/printk/printk.c:2423
_printk+0xcf/0x120 kernel/printk/printk.c:2448
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_agfl_read_verify+0x165/0x1f0 fs/xfs/libxfs/xfs_alloc.c:-1
__xfs_buf_ioend+0x342/0x6f0 fs/xfs/xfs_buf.c:1174
xfs_buf_iowait+0x167/0x480 fs/xfs/xfs_buf.c:1381
_xfs_buf_read fs/xfs/xfs_buf.c:643 [inline]
xfs_buf_read_map+0x335/0xa50 fs/xfs/xfs_buf.c:709
xfs_trans_read_buf_map+0x1d7/0x8e0 fs/xfs/xfs_trans_buf.c:304
xfs_trans_read_buf fs/xfs/xfs_trans.h:210 [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:3566
xfs_alloc_vextent_iterate_ags+0x140/0x940 fs/xfs/libxfs/xfs_alloc.c:3750
xfs_alloc_vextent_start_ag+0x388/0x850 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+0x188e/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+0x674/0xf70 fs/xfs/xfs_aops.c:489
iomap_writeback_range fs/iomap/buffered-io.c:1593 [inline]
iomap_writeback_folio+0xe75/0x1c80 fs/iomap/buffered-io.c:1718
iomap_writepages+0x162/0x2d0 fs/iomap/buffered-io.c:1770
xfs_vm_writepages+0x296/0x310 fs/xfs/xfs_aops.c:701
do_writepages+0x32e/0x550 mm/page-writeback.c:2604
__writeback_single_inode+0x145/0xff0 fs/fs-writeback.c:1719
writeback_sb_inodes+0x6c7/0x1010 fs/fs-writeback.c:2015
wb_writeback+0x43b/0xaf0 fs/fs-writeback.c:2195
wb_do_writeback fs/fs-writeback.c:2342 [inline]
wb_workfn+0x409/0xef0 fs/fs-writeback.c:2382
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245