INFO: task syz.5.254:7145 blocked for more than 143 seconds. Not tainted 6.16.0-next-20250731-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.254 state:D stack:25592 pid:7145 tgid:7143 ppid:6148 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 rwsem_down_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1086 __down_read_common kernel/locking/rwsem.c:1261 [inline] __down_read kernel/locking/rwsem.c:1274 [inline] down_read+0x98/0x2e0 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/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc50c18e9a9 RSP: 002b:00007fc50bff7038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007fc50c3b5fa0 RCX: 00007fc50c18e9a9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000101 RBP: 00007fc50c210d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fc50c3b5fa0 R15: 00007ffeac6daa88 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:3/49: 2 locks held by getty/5605: #0: ffff8880300220a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 3 locks held by syz-executor/6245: 1 lock held by syz.5.254/7145: #0: ffff888029f800e0 (&type->s_umount_key#61){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff888029f800e0 (&type->s_umount_key#61){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 1 lock held by syz-executor/7253: #0: ffffffff8e13f9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #0: ffffffff8e13f9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957 3 locks held by syz.6.745/9538: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-next-20250731-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 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] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 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: 13 Comm: kworker/u8:1 Not tainted 6.16.0-next-20250731-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: 0x0 (bat_events) 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+0x58/0x120 lib/smp_processor_id.c:19 Code: 48 8b 0d 1b 8e 26 07 48 3b 4c 24 08 0f 85 cc 00 00 00 48 83 c4 10 5b 41 5e 41 5f 5d e9 81 ca 02 00 cc 48 c7 04 24 00 00 00 00 <9c> 8f 04 24 f7 04 24 00 02 00 00 74 c8 65 4c 8b 3c 25 08 d0 9d 92 RSP: 0018:ffffc90000127b70 EFLAGS: 00000046 RAX: 0000000000000001 RBX: ffffffff8b79bd9d RCX: 0000000080000000 RDX: 0000000000000000 RSI: ffffffff8d9dccd2 RDI: ffffffff8be34100 RBP: ffffc90000127c70 R08: ffffffff8fa21837 R09: 1ffffffff1f44306 R10: dffffc0000000000 R11: fffffbfff1f44307 R12: ffff88801a4a0060 R13: dffffc0000000000 R14: 1ffff92000024f7c R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888125d43000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd07ea5fc8 CR3: 000000007826e000 CR4: 00000000003526f0 DR0: 0000000000000007 DR1: 0000000000000002 DR2: 0000000000000008 DR3: 1000000100000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: lockdep_hardirqs_off+0xab/0x110 kernel/locking/lockdep.c:4495 trace_hardirqs_off+0x12/0x40 kernel/trace/trace_preemptirq.c:104 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:117 [inline] _raw_spin_lock_irq+0x7d/0xf0 kernel/locking/spinlock.c:170 worker_thread+0xa8a/0xda0 kernel/workqueue.c:3353 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245