INFO: task syz.8.804:13087 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.804 state:D stack:26688 pid:13087 tgid:13086 ppid:12367 task_flags:0x400140 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: 0033:0x7fcd0f40c799 RSP: 002b:00007fcd0d65e028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007fcd0f685fa0 RCX: 00007fcd0f40c799 RDX: 000000003a736e6f RSI: 00002000000001c0 RDI: ffffffff80000700 RBP: 00007fcd0f4a2c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fcd0f686038 R14: 00007fcd0f685fa0 R15: 00007fff0ef3a678 Showing all locks held in the system: 1 lock held by khungtaskd/39: #0: ffffffff8ddcba80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcba80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcba80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5562: #0: ffff8880369180a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e832e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 4 locks held by syz-executor/7768: 2 locks held by syz-executor/12275: #0: ffff8880630600d0 (&type->s_umount_key#76){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880630600d0 (&type->s_umount_key#76){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff8880630600d0 (&type->s_umount_key#76){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffff888019c4f238 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_remove_by_name_ns+0x3d/0x130 fs/kernfs/dir.c:1717 1 lock held by syz.8.804/13087: #0: ffff88805d9b20d0 (&type->s_umount_key#86){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff88805d9b20d0 (&type->s_umount_key#86){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 2 locks held by syz.5.961/14918: 3 locks held by syz.0.960/14922: 3 locks held by syz.4.963/14925: 3 locks held by syz.2.962/14953: 1 lock held by udevadm/14954: 1 lock held by sed/14957: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 39 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 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: 14957 Comm: sed Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:mark_held_locks kernel/locking/lockdep.c:4317 [inline] RIP: 0010:__trace_hardirqs_on_caller kernel/locking/lockdep.c:4343 [inline] RIP: 0010:lockdep_hardirqs_on_prepare+0xfd/0x260 kernel/locking/lockdep.c:4410 Code: 48 63 83 b0 0b 00 00 49 83 c4 28 49 39 c7 7d 44 49 83 ff 31 73 2d 41 8b 44 24 20 a9 00 00 04 00 74 db 25 00 00 03 00 83 f8 01 03 00 00 00 83 da 00 48 89 df 4c 89 e6 e8 60 62 00 00 85 c0 75 RSP: 0000:ffffc9000ee37978 EFLAGS: 00000016 RAX: 0000000000010000 RBX: ffff888031875b80 RCX: 0000000080000002 RDX: 0000000000000000 RSI: ffffffff8d57bfef RDI: ffffffff8ba67200 RBP: ffffc9000ee37a78 R08: ffffffff8f6a5db7 R09: 1ffffffff1ed4bb6 R10: dffffc0000000000 R11: fffffbfff1ed4bb7 R12: ffff888031876738 R13: 0000000000000246 R14: ffff888031876738 R15: 0000000000000000 FS: 00007f4b6f760c80(0000) GS:ffff888126439000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4b6fac70f0 CR3: 000000005225e000 CR4: 00000000003526f0 Call Trace: trace_hardirqs_on+0x28/0x40 kernel/trace/trace_preemptirq.c:78 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:178 [inline] _raw_spin_unlock_irqrestore+0x30/0x80 kernel/locking/spinlock.c:194 raw_spin_unlock_irqrestore_wake include/linux/sched/wake_q.h:97 [inline] rtlock_slowlock kernel/locking/rtmutex.c:1896 [inline] rtlock_lock kernel/locking/spinlock_rt.c:43 [inline] __rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline] rt_spin_lock+0x17a/0x400 kernel/locking/spinlock_rt.c:57 spin_lock include/linux/spinlock_rt.h:45 [inline] pte_offset_map_lock+0x13d/0x210 mm/pgtable-generic.c:402 wp_page_copy mm/memory.c:3816 [inline] do_wp_page+0x1a41/0x49d0 mm/memory.c:4241 handle_pte_fault mm/memory.c:6333 [inline] __handle_mm_fault mm/memory.c:6455 [inline] handle_mm_fault+0x9f5/0x13c0 mm/memory.c:6624 do_user_addr_fault+0xa73/0x1340 arch/x86/mm/fault.c:1334 handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7f4b6fae28ec Code: 1f 80 00 00 00 00 48 8b 31 8b 51 08 4c 01 fe 48 83 fa 26 74 0a 48 83 fa 08 0f 85 ef 3c ff ff 48 8b 51 10 48 83 c1 18 4c 01 fa <48> 89 16 48 39 d9 72 d4 4d 8b 9a 08 02 00 00 4d 85 db 0f 84 ec 0b RSP: 002b:00007fff938e5500 EFLAGS: 00010206 RAX: 00007f4b6fa0acd0 RBX: 00007f4b6fa14280 RCX: 00007f4b6fa10d40 RDX: 00007f4b6fa1aa00 RSI: 00007f4b6fac70f0 RDI: 00007f4b6fa184c8 RBP: 00007fff938e5620 R08: 00007f4b6fa15f90 R09: 00007f4b6fa184c8 R10: 00007f4b6facb0c0 R11: 0000000000000000 R12: 00007fff938e55b0 R13: 00007fff938e55b0 R14: 00007f4b6facb0c0 R15: 00007f4b6fa09000