INFO: task syz-executor:5817 blocked for more than 143 seconds.
Not tainted 6.15.0-rc5-syzkaller-00300-g3ce9925823c7 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:17576 pid:5817 tgid:5817 ppid:1 task_flags:0x400140 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x168f/0x4c70 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6860
wb_wait_for_completion+0x15f/0x260 fs/fs-writeback.c:216
__writeback_inodes_sb_nr+0x1f6/0x250 fs/fs-writeback.c:2747
sync_filesystem+0xa3/0x230 fs/sync.c:54
generic_shutdown_super+0x6f/0x2c0 fs/super.c:621
bch2_kill_sb+0x41/0x50 fs/bcachefs/fs.c:2620
deactivate_locked_super+0xb9/0x130 fs/super.c:473
cleanup_mnt+0x425/0x4c0 fs/namespace.c:1431
task_work_run+0x1d1/0x260 kernel/task_work.c:227
resume_user_mode_work+0x5e/0x80 include/linux/resume_user_mode.h:50
exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x9a/0x120 kernel/entry/common.c:218
do_syscall_64+0x103/0x210 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1558d8fc97
RSP: 002b:00007ffe864ca438 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f1558e1089d RCX: 00007f1558d8fc97
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe864ca4f0
RBP: 00007ffe864ca4f0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe864cb580
R13: 00007f1558e1089d R14: 00000000000246ec R15: 00007ffe864cb5c0
Showing all locks held in the system:
3 locks held by kworker/u8:1/13:
#0: ffff8880b88399d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:605
#1: ffff8880b8823b08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39e/0x6d0 kernel/sched/psi.c:987
#2: ffff8880b8825558 (&base->lock){-.-.}-{2:2}, at: lock_timer_base kernel/time/timer.c:1046 [inline]
#2: ffff8880b8825558 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x1ae/0xf30 kernel/time/timer.c:1127
1 lock held by khungtaskd/31:
#0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764
2 locks held by kworker/u8:2/36:
#0: ffff8881412eb148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff8881412eb148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
#1: ffffc90000ad7c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc90000ad7c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
2 locks held by getty/5580:
#0: ffff8880350aa0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900033532f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by syz-executor/5817:
#0: ffff8880244440e0 (&type->s_umount_key#70){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline]
#0: ffff8880244440e0 (&type->s_umount_key#70){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff8880244440e0 (&type->s_umount_key#70){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
1 lock held by udevd/6440:
2 locks held by syz.9.329/12001:
1 lock held by syz.0.326/12007:
2 locks held by syz.6.330/12014:
1 lock held by syz.6.330/12041:
2 locks held by syz.8.332/12033:
2 locks held by syz.5.331/12025:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc5-syzkaller-00300-g3ce9925823c7 #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:274 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:437
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
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: 12014 Comm: syz.6.330 Not tainted 6.15.0-rc5-syzkaller-00300-g3ce9925823c7 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:rdtsc_ordered arch/x86/include/asm/msr.h:217 [inline]
RIP: 0010:delay_tsc+0x21/0xc0 arch/x86/lib/delay.c:70
Code: 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 53 48 89 fb bf 01 00 00 00 e8 b9 e4 42 f6 e8 34 39 01 00 89 c5 0f 01 f9 <66> 90 49 89 d6 49 c1 e6 20 49 09 c6 0f 01 f9 66 90 49 89 d7 49 c1
RSP: 0018:ffffc9001d1f7170 EFLAGS: 00000086
RAX: 000000009ff2c169 RBX: 0000000000000899 RCX: 0000000000000001
RDX: 0000000000000099 RSI: ffffffff8bc0ff80 RDI: ffffffff8bc0ff40
RBP: 0000000000000001 R08: ffff8880244c8237 R09: 1ffff11004899046
R10: dffffc0000000000 R11: ffffffff8b4de840 R12: 1ffffffff3362f8a
R13: 00000000ffffffff R14: dffffc0000000000 R15: 00000000000007a8
FS: 00007f6b76d2a6c0(0000) GS:ffff888126200000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1557dd4000 CR3: 000000002943a000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
udelay include/asm-generic/delay.h:62 [inline]
wait_for_lsr+0x160/0x2f0 drivers/tty/serial/8250/8250_port.c:2104
fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3348 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3371 [inline]
serial8250_console_write+0x134c/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
ovl_make_workdir fs/overlayfs/super.c:710 [inline]
ovl_get_workdir+0xf65/0x1700 fs/overlayfs/super.c:827
ovl_fill_super+0x1386/0x35d0 fs/overlayfs/super.c:1406
vfs_get_super fs/super.c:1280 [inline]
get_tree_nodev+0xb8/0x150 fs/super.c:1299
vfs_get_tree+0x8f/0x2b0 fs/super.c:1759
do_new_mount+0x24a/0xa40 fs/namespace.c:3881
do_mount fs/namespace.c:4221 [inline]
__do_sys_mount fs/namespace.c:4432 [inline]
__se_sys_mount+0x317/0x410 fs/namespace.c:4409
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6b75f8e969
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6b76d2a038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f6b761b5fa0 RCX: 00007f6b75f8e969
RDX: 0000200000000d40 RSI: 0000200000000080 RDI: 0000000000000000
RBP: 00007f6b76010ab1 R08: 00002000000001c0 R09: 0000000000000000
R10: 0000000000010000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f6b761b5fa0 R15: 00007fff3795d4b8