INFO: task syz-executor:5764 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:21704 pid:5764 ppid:1 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x1553/0x45a0 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
wb_wait_for_completion+0x173/0x2a0 fs/fs-writeback.c:192
sync_inodes_sb+0x1c9/0xa10 fs/fs-writeback.c:2772
sync_filesystem+0x171/0x220 fs/sync.c:64
generic_shutdown_super+0x6f/0x2b0 fs/super.c:666
kill_block_super+0x44/0x90 fs/super.c:1660
deactivate_locked_super+0x97/0x100 fs/super.c:481
cleanup_mnt+0x43b/0x4d0 fs/namespace.c:1259
task_work_run+0x1d4/0x260 kernel/task_work.c:245
exit_task_work include/linux/task_work.h:43 [inline]
do_exit+0x95a/0x2460 kernel/exit.c:883
do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
__do_sys_exit_group kernel/exit.c:1035 [inline]
__se_sys_exit_group kernel/exit.c:1033 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fc56759aeb9
RSP: 002b:00007ffdeb39b1f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fc5676047ae RCX: 00007fc56759aeb9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 000000000000000c R08: 0000000000000000 R09: 00007fc56760471f
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdeb39c4b0
R13: 00007fc56760471f R14: 000055555ada14e8 R15: 00007ffdeb39d580
Showing all locks held in the system:
1 lock held by khungtaskd/28:
#0: ffffffff8d131fe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8d131fe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8d131fe0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by kworker/u4:5/79:
2 locks held by getty/5523:
#0: ffff8880319ea0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217
2 locks held by syz-executor/5764:
#0: ffff8880268380e0 (&type->s_umount_key#68){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline]
#0: ffff8880268380e0 (&type->s_umount_key#68){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff8880268380e0 (&type->s_umount_key#68){++++}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513
#1: ffff888140b8a7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
#1: ffff888140b8a7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1ad/0xa10 fs/fs-writeback.c:2770
1 lock held by segctord/6047:
1 lock held by syz.6.431/8079:
#0: ffff8880268380e0 (&type->s_umount_key#68){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
#0: ffff8880268380e0 (&type->s_umount_key#68){++++}-{3:3}, at: super_lock+0x17f/0x3a0 fs/super.c:117
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf3d/0xf80 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 6047 Comm: segctord Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:lockdep_hardirqs_off+0x7f/0x100 kernel/locking/lockdep.c:4461
Code: 65 8b 05 0c 49 7e 75 85 c0 74 56 65 4c 8b 35 08 78 7f 75 48 c7 c7 00 c9 ca 8a e8 2c 14 00 00 65 c7 05 e9 48 7e 75 00 00 00 00 <49> 89 9e 88 0a 00 00 41 8b 86 78 0a 00 00 ff c0 41 89 86 78 0a 00
RSP: 0018:ffffc90004eef288 EFLAGS: 00000086
RAX: 0000000000000000 RBX: ffffffff8a8de26f RCX: 3881bd1541501b00
RDX: dffffc0000000000 RSI: ffffffff8acac900 RDI: ffffffff8b1c81e0
RBP: ffffc90004eef340 R08: ffffffff8e8adfaf R09: 1ffffffff1d15bf5
R10: dffffc0000000000 R11: fffffbfff1d15bf6 R12: dffffc0000000000
R13: ffff8880594e8000 R14: ffff888021673c00 R15: 1ffff920009dde58
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdeaf1e0ad8 CR3: 000000000cf32000 CR4: 00000000003506f0
DR0: 000000000000afe8 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
trace_hardirqs_off+0x12/0x40 kernel/trace/trace_preemptirq.c:87
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline]
_raw_spin_lock_irqsave+0x8f/0x100 kernel/locking/spinlock.c:162
__debug_check_no_obj_freed lib/debugobjects.c:979 [inline]
debug_check_no_obj_freed+0x13a/0x540 lib/debugobjects.c:1020
free_pages_prepare mm/page_alloc.c:1187 [inline]
free_unref_page_prepare+0x1da/0x8c0 mm/page_alloc.c:2365
free_unref_page+0x32/0x2e0 mm/page_alloc.c:2458
discard_slab mm/slub.c:2127 [inline]
__unfreeze_partials+0x1cf/0x210 mm/slub.c:2667
put_cpu_partial+0x17c/0x250 mm/slub.c:2743
__slab_free+0x319/0x400 mm/slub.c:3700
qlink_free mm/kasan/quarantine.c:166 [inline]
qlist_free_all+0x75/0xd0 mm/kasan/quarantine.c:185
kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:306
kasan_slab_alloc include/linux/kasan.h:188 [inline]
slab_post_alloc_hook+0x6e/0x4b0 mm/slab.h:767
slab_alloc_node mm/slub.c:3495 [inline]
slab_alloc mm/slub.c:3503 [inline]
__kmem_cache_alloc_lru mm/slub.c:3510 [inline]
kmem_cache_alloc+0x11a/0x2d0 mm/slub.c:3519
nilfs_segbuf_new+0x4c/0x250 fs/nilfs2/segbuf.c:38
nilfs_segctor_begin_construction fs/nilfs2/segment.c:1321 [inline]
nilfs_segctor_do_construct+0xafd/0x68a0 fs/nilfs2/segment.c:2084
nilfs_segctor_construct+0x17b/0x690 fs/nilfs2/segment.c:2454
nilfs_segctor_thread_construct fs/nilfs2/segment.c:2562 [inline]
nilfs_segctor_thread+0x536/0x10d0 fs/nilfs2/segment.c:2646
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293