INFO: task syz.2.999:13496 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.999 state:D stack:26688 pid:13496 tgid:13495 ppid:12643 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289 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 user_get_super+0xc8/0x120 fs/super.c:1001 quotactl_block fs/quota/quota.c:889 [inline] __do_sys_quotactl fs/quota/quota.c:955 [inline] __se_sys_quotactl+0x540/0x9e0 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: 0033:0x7f865ecac819 RSP: 002b:00007f865cf06028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f865ef25fa0 RCX: 00007f865ecac819 RDX: 000000000000ee00 RSI: 00002000000000c0 RDI: ffffffff80000600 RBP: 00007f865ed42c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000200000000100 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f865ef26038 R14: 00007f865ef25fa0 R15: 00007ffdd169f898 Showing all locks held in the system: 3 locks held by kworker/u8:0/12: 1 lock held by khungtaskd/38: #0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5552: #0: ffff88823be6c0a0 (&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 4 locks held by syz-executor/5795: 1 lock held by udevd/8981: #0: ffff888032c661a0 (&group->mark_mutex){+.+.}-{4:4}, at: fsnotify_group_lock include/linux/fsnotify_backend.h:289 [inline] #0: ffff888032c661a0 (&group->mark_mutex){+.+.}-{4:4}, at: fsnotify_destroy_mark+0x3b/0x290 fs/notify/mark.c:599 1 lock held by udevd/9005: 1 lock held by udevd/11196: #0: ffff888032c661a0 (&group->mark_mutex){+.+.}-{4:4}, at: fsnotify_group_lock include/linux/fsnotify_backend.h:289 [inline] #0: ffff888032c661a0 (&group->mark_mutex){+.+.}-{4:4}, at: fsnotify_destroy_mark+0x3b/0x290 fs/notify/mark.c:599 1 lock held by syz.2.999/13496: #0: ffff888021fde0d0 (&type->s_umount_key#74){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff888021fde0d0 (&type->s_umount_key#74){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz.9.1366/15852: 2 locks held by syz.7.1371/15896: 4 locks held by syz.5.1373/15897: 2 locks held by sed/15901: ============================================= 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 03/18/2026 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 12 Comm: kworker/u8:0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: bat_events batadv_tt_purge RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline] RIP: 0010:lock_release+0x25e/0x3d0 kernel/locking/lockdep.c:5891 Code: 89 c5 7f d0 4c 89 ff 4c 89 f6 48 8b 54 24 18 e8 38 2f 00 00 48 8b 5c 24 08 48 c7 c7 68 20 7c 8d e8 27 e3 83 09 b8 ff ff ff ff <65> 0f c1 05 fa bb ae 10 83 f8 01 75 2e 9c 58 a9 00 02 00 00 75 42 RSP: 0018:ffffc90000117840 EFLAGS: 00000002 RAX: 00000000ffffffff RBX: 0000000000000002 RCX: 0000000080000001 RDX: 0000000000000004 RSI: ffffffff8d7c2068 RDI: ffffffff8ba67a00 RBP: ffff88801c6b8c58 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000022f04 R12: 0000000000000004 R13: 0000000000000004 R14: ffff88809006ce18 R15: ffff88801c6b8000 FS: 0000000000000000(0000) GS:ffff888126332000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6b939ca000 CR3: 00000000629a4000 CR4: 00000000003526f0 Call Trace: __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:176 [inline] _raw_spin_unlock_irqrestore+0x1b/0x80 kernel/locking/spinlock.c:194 unlock_rt_mutex_safe kernel/locking/rtmutex.c:344 [inline] rt_mutex_slowunlock+0x4a7/0x8b0 kernel/locking/rtmutex.c:1454 spin_unlock_bh include/linux/spinlock_rt.h:115 [inline] batadv_tt_local_purge+0x2ed/0x380 net/batman-adv/translation-table.c:1315 batadv_tt_purge+0x35/0xa10 net/batman-adv/translation-table.c:3509 process_one_work kernel/workqueue.c:3276 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440 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