INFO: task syz.3.64:6419 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.64 state:D stack:25592 pid:6419 tgid:6418 ppid:5796 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1480/0x50a0 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7241
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked+0x1dfe/0x25e0 kernel/locking/rtmutex.c:1760
__rwbase_read_lock+0xbc/0x180 kernel/locking/rwbase_rt.c:114
rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline]
__down_read kernel/locking/rwsem.c:1466 [inline]
down_read+0x127/0x1f0 kernel/locking/rwsem.c:1539
__super_lock fs/super.c:59 [inline]
super_lock+0x2a9/0x3b0 fs/super.c:121
__iterate_supers+0x126/0x290 fs/super.c:923
quota_sync_all fs/quota/quota.c:69 [inline]
__do_sys_quotactl fs/quota/quota.c:938 [inline]
__se_sys_quotactl+0x353/0x950 fs/quota/quota.c:917
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0600d2f749
RSP: 002b:00007f05fef8e038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f0600f85fa0 RCX: 00007f0600d2f749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000101
RBP: 00007f0600db3f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0600f86038 R14: 00007f0600f85fa0 R15: 00007fff912fd7c8
Showing all locks held in the system:
1 lock held by khungtaskd/38:
#0: ffffffff8d5ae8c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d5ae8c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8d5ae8c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:5/69:
8 locks held by kworker/u8:8/998:
2 locks held by kworker/u8:9/1179:
#0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc90004e57b80 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc90004e57b80 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
2 locks held by kworker/u8:10/1210:
4 locks held by kworker/u8:15/3552:
1 lock held by udevd/5167:
2 locks held by getty/5558:
#0: ffff888034fe20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x44f/0x1460 drivers/tty/n_tty.c:2211
3 locks held by syz-executor/5797:
7 locks held by kworker/u8:18/6190:
1 lock held by syz.3.64/6419:
#0: ffff88804ec900d0 (&type->s_umount_key#64){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
#0: ffff88804ec900d0 (&type->s_umount_key#64){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
2 locks held by syz-executor/6434:
#0: ffff88803a3240d0 (&type->s_umount_key#56){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88803a3240d0 (&type->s_umount_key#56){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88803a3240d0 (&type->s_umount_key#56){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
#1: ffff888026f808c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:397 [inline]
#1: ffff888026f808c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x1af/0xb80 fs/fs-writeback.c:2892
2 locks held by udevd/6717:
10 locks held by kworker/u8:23/6847:
2 locks held by kworker/u8:24/6905:
#0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc90004447b80 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc90004447b80 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
2 locks held by kworker/u8:25/7030:
1 lock held by udevd/7162:
7 locks held by kworker/u8:26/7218:
4 locks held by syz.8.228/8017:
2 locks held by syz.9.232/8031:
#0: ffff88802ee2c0d0 (&type->s_umount_key#52/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xab0 fs/super.c:344
#1: ffffffff8d456998 (wq_pool_mutex){+.+.}-{4:4}, at: apply_wqattrs_lock kernel/workqueue.c:5215 [inline]
#1: ffffffff8d456998 (wq_pool_mutex){+.+.}-{4:4}, at: __alloc_workqueue+0xa07/0x1b80 kernel/workqueue.c:5768
2 locks held by syz.5.230/8035:
1 lock held by udevadm/8038:
2 locks held by syz.6.233/8040:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 7218 Comm: kworker/u8:26 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: btrfs-endio-meta simple_end_io_work
RIP: 0010:__bfs kernel/locking/lockdep.c:1815 [inline]
RIP: 0010:__bfs_backwards kernel/locking/lockdep.c:1860 [inline]
RIP: 0010:check_irq_usage kernel/locking/lockdep.c:2796 [inline]
RIP: 0010:check_prev_add kernel/locking/lockdep.c:3169 [inline]
RIP: 0010:check_prevs_add kernel/locking/lockdep.c:3284 [inline]
RIP: 0010:validate_chain kernel/locking/lockdep.c:3908 [inline]
RIP: 0010:__lock_acquire+0x197c/0x2cf0 kernel/locking/lockdep.c:5237
Code: 13 25 ff 0f 00 00 39 05 ce 73 1c 11 73 06 89 05 c6 73 1c 11 48 8b 02 48 89 df 4c 39 e8 0f 84 2c fe ff ff 4c 89 60 30 48 8b 00 <4c> 39 e8 75 f4 48 89 df e9 18 fe ff ff 48 89 fb 48 c7 c7 50 e0 47
RSP: 0018:ffffc90007d873b8 EFLAGS: 00000002
RAX: ffffffff95447308 RBX: 00000000000003cd RCX: 000000000000043d
RDX: ffffffff953ee758 RSI: ffff88802d968ca8 RDI: 00000000000003cd
RBP: 16185892f32628aa R08: ffffc90007d87380 R09: 0000000000000020
R10: dffffc0000000000 R11: ffffffff819d78c0 R12: ffffffff953ee988
R13: ffffffff925c0160 R14: ffff88802d968000 R15: 000000000000043c
FS: 0000000000000000(0000) GS:ffff888126e01000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6706795000 CR3: 000000003c83e000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0x117/0x340 kernel/locking/lockdep.c:5868
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162
debug_object_activate+0x72/0x4e0 lib/debugobjects.c:818
debug_timer_activate kernel/time/timer.c:793 [inline]
__mod_timer+0xa73/0xf60 kernel/time/timer.c:1124
queue_delayed_work_on+0x18b/0x280 kernel/workqueue.c:2555
queue_delayed_work include/linux/workqueue.h:684 [inline]
wb_inode_writeback_end mm/page-writeback.c:2975 [inline]
__folio_end_writeback+0x50f/0x760 mm/page-writeback.c:2999
folio_end_writeback_no_dropbehind+0x151/0x290 mm/filemap.c:1661
folio_end_writeback+0xea/0x220 mm/filemap.c:1687
end_bbio_meta_write+0x2ee/0x4f0 fs/btrfs/extent_io.c:2178
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
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