INFO: task syz.2.280:8301 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.280 state:D stack:25760 pid:8301 tgid:8300 ppid:8097 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x1472/0x4fe0 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7245 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:59 [inline] super_lock+0x2d6/0x3d0 fs/super.c:121 user_get_super+0xc8/0x120 fs/super.c:998 quotactl_block fs/quota/quota.c:890 [inline] __do_sys_quotactl fs/quota/quota.c:955 [inline] __se_sys_quotactl+0x516/0x990 fs/quota/quota.c:917 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4066baaeb9 RSP: 002b:00007f4064e06028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f4066e25fa0 RCX: 00007f4066baaeb9 RDX: 0000000000000000 RSI: 00002000000000c0 RDI: ffffffff80000802 RBP: 00007f4066c18c1f R08: 0000000000000000 R09: 0000000000000000 R10: 00002000000002c0 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4066e26038 R14: 00007f4066e25fa0 R15: 00007fff6e7702f8 Showing all locks held in the system: 1 lock held by khungtaskd/38: #0: ffffffff8dbc77c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8dbc77c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8dbc77c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:3/58: 4 locks held by kworker/u8:4/59: 2 locks held by getty/5559: #0: ffff88814dfba0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e7e2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 2 locks held by syz-executor/5797: 1 lock held by syz.2.280/8301: #0: ffff88803fc700d0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff88803fc700d0 (&type->s_umount_key#55){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:121 1 lock held by udevd/8905: 1 lock held by udevd/8931: 3 locks held by syz.6.368/9798: 1 lock held by syz.5.369/9805: 1 lock held by syz.4.371/9827: 4 locks held by syz.3.372/9848: 1 lock held by syz.1.373/9853: #0: ffff88803fc700d0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff88803fc700d0 (&type->s_umount_key#55){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:121 1 lock held by syz.1.373/9854: #0: ffff88803fc700d0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff88803fc700d0 (&type->s_umount_key#55){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:121 1 lock held by syz.1.373/9855: #0: ffff88803fc700d0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff88803fc700d0 (&type->s_umount_key#55){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:121 1 lock held by syz.1.373/9856: #0: ffff88803fc700d0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff88803fc700d0 (&type->s_umount_key#55){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:121 1 lock held by syz.1.373/9859: #0: ffff88803fc700d0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff88803fc700d0 (&type->s_umount_key#55){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:121 1 lock held by syz.1.373/9860: #0: ffff88803fc700d0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff88803fc700d0 (&type->s_umount_key#55){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:121 1 lock held by syz.1.373/9862: #0: ffff88803fc700d0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff88803fc700d0 (&type->s_umount_key#55){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:121 1 lock held by syz.1.373/9863: #0: ffff88803fc700d0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff88803fc700d0 (&type->s_umount_key#55){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:121 1 lock held by udevadm/9857: ============================================= 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 01/24/2026 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+0xf90/0xfe0 kernel/hung_task.c:515 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 8882 Comm: syz-executor Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 RIP: 0033:0x7f6807716070 Code: 06 00 00 ff ff ff ff f0 83 88 08 03 00 00 10 64 48 8b 3c 25 00 03 00 00 e8 1d 50 06 00 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 <53> 49 89 ca 64 48 8b 1c 25 10 00 00 00 8b 83 08 03 00 00 80 3d ce RSP: 002b:00007ffeab22de28 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 0000000000000024 RCX: 0000000000000000 RDX: 0000000040000001 RSI: 00007ffeab22deac RDI: ffffffffffffffff RBP: 00007ffeab22deac R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000001388 R13: 00000000000927c0 R14: 0000000000089332 R15: 00007ffeab22df00 FS: 000055556ad15500 GS: 0000000000000000