INFO: task syz.0.77:6435 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.77 state:D stack:28952 pid:6435 tgid:6429 ppid:5801 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x145f/0x5070 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 percpu_rwsem_wait+0x2e6/0x330 kernel/locking/percpu-rwsem.c:164 __percpu_down_read+0xfc/0x140 kernel/locking/percpu-rwsem.c:180 percpu_down_read_internal include/linux/percpu-rwsem.h:67 [inline] percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] __sb_start_write include/linux/fs/super.h:19 [inline] sb_start_write include/linux/fs/super.h:125 [inline] quotactl_block fs/quota/quota.c:899 [inline] __do_sys_quotactl fs/quota/quota.c:955 [inline] __se_sys_quotactl+0x83c/0x950 fs/quota/quota.c:917 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff9317df749 RSP: 002b:00007ff92f5d9038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007ff931a36270 RCX: 00007ff9317df749 RDX: 0000000000000000 RSI: 0000200000000000 RDI: ffffffff80000801 RBP: 00007ff931863f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff931a36308 R14: 00007ff931a36270 R15: 00007ffc52a1c8f8 Showing all locks held in the system: 1 lock held by khungtaskd/38: #0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:11/1379: 2 locks held by getty/5557: #0: ffff8880346050a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e762e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x44f/0x1460 drivers/tty/n_tty.c:2211 3 locks held by syz-executor/5803: 1 lock held by udevd/5924: 1 lock held by syz.0.77/6435: #0: ffff888039fdc480 (sb_writers#22){++++}-{0:0}, at: do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] #0: ffff888039fdc480 (sb_writers#22){++++}-{0:0}, at: do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 3 locks held by syz-executor/6461: 1 lock held by syz-executor/6644: 1 lock held by syz.4.342/8255: 4 locks held by syz.3.343/8266: 1 lock held by udevadm/8286: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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:160 [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+0xf95/0xfe0 kernel/hung_task.c:515 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 8286 Comm: udevadm Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:hlock_class kernel/locking/lockdep.c:234 [inline] RIP: 0010:reacquire_held_locks+0x71/0x190 kernel/locking/lockdep.c:5386 Code: 45 31 ff eb 10 41 ff cf 49 83 c6 28 44 39 fd 0f 84 f4 00 00 00 49 8b 7e ec 41 8b 46 fc 25 ff 1f 00 00 48 0f a3 05 ef d2 1d 11 <73> 10 48 69 c0 c8 00 00 00 48 8d 80 90 b3 5b 92 eb 3c 83 3d f6 62 RSP: 0018:ffffc90011ae7c68 EFLAGS: 00000003 RAX: 000000000000000b RBX: ffffc90011ae7cbc RCX: ffffc90011ae7cbc RDX: 0000000000000002 RSI: 0000000000000003 RDI: ffffffff8d5ae940 RBP: 00000000ffffffff R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff1db668f R12: 0000000000000002 R13: 0000000000000002 R14: ffff88802e870c04 R15: 0000000000000000 FS: 00007f42d0b75880(0000) GS:ffff888126def000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000056431ffee5f8 CR3: 0000000019736000 CR4: 00000000003526f0 Call Trace: __lock_release kernel/locking/lockdep.c:5574 [inline] lock_release+0x19a/0x3b0 kernel/locking/lockdep.c:5889 rt_spin_unlock+0x29/0x200 kernel/locking/spinlock_rt.c:80 spin_unlock include/linux/spinlock_rt.h:105 [inline] fast_dput+0x233/0x430 fs/dcache.c:-1 dput+0xe8/0x1a0 fs/dcache.c:924 __fput+0x69d/0xa80 fs/file_table.c:476 fput_close_sync+0x113/0x220 fs/file_table.c:573 __do_sys_close fs/open.c:1573 [inline] __se_sys_close fs/open.c:1558 [inline] __x64_sys_close+0x7f/0x110 fs/open.c:1558 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f42d0cd1a67 Code: 44 00 00 48 83 ec 10 48 63 ff 45 31 c9 45 31 c0 6a 01 31 c9 e8 ca 19 f9 ff 48 83 c4 18 c3 0f 1f 44 00 00 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 61 b3 0d 00 f7 d8 64 89 02 b8 RSP: 002b:00007ffde0149cb8 EFLAGS: 00000297 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 000056431ffdb2a0 RCX: 00007f42d0cd1a67 RDX: 00007f42d0dabea0 RSI: 000056431ffecae0 RDI: 0000000000000005 RBP: 00007f42d0dabff0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000297 R12: 0000000000000000 R13: 3d45505954564544 R14: 3d5845444e494649 R15: 3d454d414e564544