INFO: task syz.3.848:13616 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.848 state:D stack:24328 pid:13616 tgid:13615 ppid:5603 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x16dc/0x5500 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7607 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1670 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1747 [inline] __rt_mutex_slowlock_locked+0x1f84/0x25b0 kernel/locking/rtmutex.c:1787 __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:1502 [inline] down_read+0x132/0x200 kernel/locking/rwsem.c:1576 __super_lock fs/super.c:60 [inline] super_lock+0x2d6/0x3d0 fs/super.c:122 __iterate_supers+0x120/0x240 fs/super.c:866 quota_sync_all fs/quota/quota.c:69 [inline] __do_sys_quotactl fs/quota/quota.c:938 [inline] __se_sys_quotactl+0x3a0/0x9a0 fs/quota/quota.c:917 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd38718de59 RSP: 002b:00007fd3853e6028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007fd387415fa0 RCX: 00007fd38718de59 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000101 RBP: 00007fd387223e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd387416038 R14: 00007fd387415fa0 R15: 00007ffea9b5a6a8 Showing all locks held in the system: 1 lock held by khungtaskd/38: #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:11/1413: #0: ffff888032990938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff888032990938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc90006ab7c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc90006ab7c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff8f5b0fb8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f5b0fb8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x123/0x16e0 net/ipv6/addrconf.c:4229 3 locks held by kworker/u8:14/3330: #0: ffff88801aea0938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88801aea0938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc9000f20fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc9000f20fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff8f5a2400 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:673 2 locks held by kworker/u8:15/3356: #0: ffff88813ff5c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88813ff5c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc9000f1afc40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc9000f1afc40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 3 locks held by dhcpcd/5260: 2 locks held by getty/5351: #0: ffff8880365040a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cc62e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211 2 locks held by syz-executor/5601: 3 locks held by kworker/1:5/5729: #0: ffff88813ff1b938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88813ff1b938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc90004f3fc40 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc90004f3fc40 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff8e1c91b0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857 3 locks held by kworker/1:2/10781: #0: ffff88813ff1b938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88813ff1b938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc900044cfc40 (netdev_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc900044cfc40 (netdev_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff8f5b0fb8 (rtnl_mutex){+.+.}-{4:4}, at: netdev_work_proc+0x72/0x7f0 net/core/netdev_work.c:116 1 lock held by syz.3.848/13616: #0: ffff8880254e20d0 (&type->s_umount_key#74){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880254e20d0 (&type->s_umount_key#74){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 5 locks held by kworker/u8:9/13948: 1 lock held by syz.2.877/14165: #0: ffff8880254e20d0 (&type->s_umount_key#74){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880254e20d0 (&type->s_umount_key#74){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 7 locks held by syz-executor/14412: 1 lock held by syz.7.927/14615: #0: ffff888061e1c0d0 (&type->s_umount_key#55){++++}-{4:4}, at: do_remount fs/namespace.c:3404 [inline] #0: ffff888061e1c0d0 (&type->s_umount_key#55){++++}-{4:4}, at: path_mount+0xd04/0x1040 fs/namespace.c:4153 2 locks held by udevadm/14662: 1 lock held by modprobe/14663: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65 trigger_all_cpu_backtrace include/linux/nmi.h:162 [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:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 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: 11 Comm: kworker/0:0H Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: xfs-log/loop7 xlog_ioend_work RIP: 0010:_find_first_zero_bit+0x9a/0xb0 lib/find_bit.c:149 Code: 45 31 e4 4d 89 f5 eb 12 49 8b 45 00 49 83 c6 08 49 83 c5 08 48 83 f8 ff 75 ba 49 83 c4 40 49 39 dc 73 c7 4c 89 f0 48 c1 e8 03 <42> 80 3c 38 00 74 d7 4c 89 f7 e8 17 b3 6d fd eb cd 0f 1f 44 00 00 RSP: 0000:ffffc90000107578 EFLAGS: 00000802 RAX: 1ffffffff26bf267 RBX: 0000000000100000 RCX: 0000000000000001 RDX: 00000000ed71b578 RSI: 0000000000100000 RDI: ffffffff935f24d0 RBP: afd5e8d172a2196b R08: ffffffff8b4467c6 R09: 0000000000080000 R10: 0000000000000000 R11: ffff88801ca8a9f8 R12: 0000000000037340 R13: ffffffff935f9338 R14: ffffffff935f9338 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888125c49000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055558907da68 CR3: 0000000040a70000 CR4: 00000000003526f0 Call Trace: find_first_zero_bit include/linux/find.h:391 [inline] alloc_lock_chain kernel/locking/lockdep.c:3714 [inline] add_chain_cache kernel/locking/lockdep.c:3746 [inline] lookup_chain_cache_add kernel/locking/lockdep.c:3855 [inline] validate_chain kernel/locking/lockdep.c:3876 [inline] __lock_acquire+0xb46/0x2ce0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:158 mark_wakeup_next_waiter kernel/locking/rtmutex.c:1331 [inline] rt_mutex_slowunlock+0x1d6/0xa20 kernel/locking/rtmutex.c:1480 rt_spin_unlock+0x10d/0x200 kernel/locking/spinlock_rt.c:84 spin_unlock_irqrestore include/linux/spinlock_rt.h:129 [inline] __wake_up_common_lock+0x190/0x1f0 kernel/sched/wait.c:127 xlog_state_clean_iclog+0x5a5/0x880 fs/xfs/xfs_log.c:2302 xlog_state_do_iclog_callbacks fs/xfs/xfs_log.c:2418 [inline] xlog_state_do_callback+0x603/0xd80 fs/xfs/xfs_log.c:2438 xlog_ioend_work+0xc6/0x100 fs/xfs/xfs_log.c:1208 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245