INFO: task syz.4.540:10268 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.540 state:D stack:26688 pid:10268 tgid:10267 ppid:7634 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x1553/0x5240 kernel/sched/core.c:6908
__schedule_loop kernel/sched/core.c:6990 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7286
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760
__rwbase_read_lock+0xc3/0x180 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+0x132/0x200 kernel/locking/rwsem.c:1539
__super_lock fs/super.c:60 [inline]
super_lock+0x2d6/0x3d0 fs/super.c:122
__iterate_supers+0x126/0x290 fs/super.c:926
quota_sync_all fs/quota/quota.c:69 [inline]
__do_sys_quotactl fs/quota/quota.c:938 [inline]
__se_sys_quotactl+0x3a7/0x9e0 fs/quota/quota.c:917
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc86cefc799
RSP: 002b:00007fc86b14e028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007fc86d175fa0 RCX: 00007fc86cefc799
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000101
RBP: 00007fc86cf92c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc86d176038 R14: 00007fc86d175fa0 R15: 00007ffe415382b8
Showing all locks held in the system:
5 locks held by kworker/u8:0/12:
8 locks held by kworker/u8:1/13:
1 lock held by khungtaskd/37:
#0: ffffffff8ddcb880 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8ddcb880 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8ddcb880 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:5/82:
#0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358
#1: ffffc9000159fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc9000159fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358
#2: ffffffff8f15a7b8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313
3 locks held by kworker/u8:9/4142:
#0: ffff888034962138 ((wq_completion)loop0){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff888034962138 ((wq_completion)loop0){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358
#1: ffffc9000f2b7c40 ((work_completion)(&worker->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc9000f2b7c40 ((work_completion)(&worker->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358
#2: ffff888025f69160 (&lo->lo_work_lock){+.+.}-{3:3}, at: spin_lock_irq include/linux/spinlock_rt.h:96 [inline]
#2: ffff888025f69160 (&lo->lo_work_lock){+.+.}-{3:3}, at: loop_process_work+0x125/0x11b0 drivers/block/loop.c:1953
5 locks held by kworker/u8:11/4538:
11 locks held by kworker/u9:1/5111:
2 locks held by getty/5556:
#0: ffff888037c0d0a0 (&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+0x462/0x13c0 drivers/tty/n_tty.c:2211
2 locks held by syz-executor/8570:
1 lock held by syz.4.540/10268:
#0: ffff888033d360d0 (&type->s_umount_key#60){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff888033d360d0 (&type->s_umount_key#60){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
1 lock held by syz.5.543/10282:
#0: ffff888033d360d0 (&type->s_umount_key#60){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff888033d360d0 (&type->s_umount_key#60){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
1 lock held by udevd/10564:
1 lock held by syz.7.656/11412:
#0: ffff888033d360d0 (&type->s_umount_key#60){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff888033d360d0 (&type->s_umount_key#60){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
3 locks held by kworker/0:8/11640:
#0: ffff88803273c538 ((wq_completion)mld){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff88803273c538 ((wq_completion)mld){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358
#1: ffffc9000589fc40 ((work_completion)(&(&idev->mc_ifc_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc9000589fc40 ((work_completion)(&(&idev->mc_ifc_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358
#2: ffff888025186628 (&idev->mc_lock){+.+.}-{4:4}, at: mld_ifc_work+0x2d/0xe70 net/ipv6/mcast.c:2692
1 lock held by syz.2.725/11960:
#0: ffff888033d360d0 (&type->s_umount_key#60){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff888033d360d0 (&type->s_umount_key#60){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
12 locks held by syz.0.736/12053:
2 locks held by syz.5.739/12071:
1 lock held by cmp/12073:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [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+0xfd9/0x1030 kernel/hung_task.c:515
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
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: 8570 Comm: syz-executor Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline]
RIP: 0010:check_preemption_disabled+0x29/0xe0 lib/smp_processor_id.c:19
Code: 90 55 41 57 41 56 53 65 8b 05 47 73 2b 07 65 8b 0d 3c 73 2b 07 f7 c1 ff ff ff 7f 74 0c 5b 41 5e 41 5f 5d e9 99 a5 03 00 cc 9c <59> f7 c1 00 02 00 00 74 ea 65 4c 8b 3d ee 72 2b 07 41 f6 47 2f 04
RSP: 0000:ffffc90006adf340 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000202 RCX: 0000000080000000
RDX: 0000000000000001 RSI: ffffffff8d7bcc1e RDI: ffffffff8ba66500
RBP: ffff888028ee0be0 R08: ffffc90006adfdd0 R09: 0000000000000000
R10: ffffc90006adf4f8 R11: fffff52000d5bea1 R12: 0000000000000001
R13: 0000000000000001 R14: ffffffff8ddcb880 R15: ffff888028ee0000
FS: 0000555594435500(0000) GS:ffff88812643c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb56e8b3810 CR3: 000000004f1ca000 CR4: 00000000003526f0
Call Trace:
lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline]
lock_release+0x259/0x3d0 kernel/locking/lockdep.c:5891
rcu_lock_release include/linux/rcupdate.h:322 [inline]
rcu_read_unlock include/linux/rcupdate.h:881 [inline]
class_rcu_destructor include/linux/rcupdate.h:1193 [inline]
unwind_next_frame+0x1aaa/0x23c0 arch/x86/kernel/unwind_orc.c:695
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4542 [inline]
slab_alloc_node mm/slub.c:4869 [inline]
kmem_cache_alloc_noprof+0x33b/0x680 mm/slub.c:4876
__xfs_trans_alloc+0x26/0x410 fs/xfs/xfs_trans.c:220
xfs_trans_alloc+0xd7/0x9b0 fs/xfs/xfs_trans.c:254
xfs_vn_sync_lazytime+0xaf/0x150 fs/xfs/xfs_iops.c:1238
sync_lazytime+0x12d/0x2d0 fs/fs-writeback.c:1721
iput+0x230/0xe80 fs/inode.c:1997
__dentry_kill+0x1a2/0x5e0 fs/dcache.c:670
shrink_kill+0xa9/0x2c0 fs/dcache.c:1147
shrink_dentry_list+0x2e3/0x5e0 fs/dcache.c:1174
shrink_dcache_tree+0xcf/0x310 fs/dcache.c:-1
do_one_tree fs/dcache.c:1654 [inline]
shrink_dcache_for_umount+0xa8/0x1f0 fs/dcache.c:1671
generic_shutdown_super+0x6f/0x2d0 fs/super.c:624
kill_block_super+0x44/0x90 fs/super.c:1725
xfs_kill_sb+0x15/0x50 fs/xfs/xfs_super.c:2284
deactivate_locked_super+0xbc/0x130 fs/super.c:476
cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312
task_work_run+0x1d9/0x270 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa6b316d9d7
Code: a2 c7 05 1c fd 24 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffd6fc5f7e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fa6b3202050 RCX: 00007fa6b316d9d7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd6fc5f8a0
RBP: 00007ffd6fc5f8a0 R08: 00007ffd6fc608a0 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd6fc60930
R13: 00007fa6b3202050 R14: 000000000004febe R15: 00007ffd6fc60970