INFO: task syz.2.435:8325 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.435       state:D stack:26792 pid:8325  tgid:8324  ppid:5804   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5387 [inline]
 __schedule+0x1681/0x54c0 kernel/sched/core.c:7188
 __schedule_loop kernel/sched/core.c:7267 [inline]
 rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7563
 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1659 [inline]
 __rt_mutex_slowlock kernel/locking/rtmutex.c:1736 [inline]
 __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1776
 __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:1496 [inline]
 down_read+0x132/0x200 kernel/locking/rwsem.c:1570
 __super_lock fs/super.c:60 [inline]
 super_lock+0x2d6/0x3d0 fs/super.c:122
 __iterate_supers+0x126/0x250 fs/super.c:926
 ksys_sync fs/sync.c:102 [inline]
 __ia32_sys_sync+0xa0/0x120 fs/sync.c:111
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd4c81cc819
RSP: 002b:00007fd4c6426028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fd4c8445fa0 RCX: 00007fd4c81cc819
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fd4c8445fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd4c8446038 R14: 00007fd4c8445fa0 R15: 00007ffdb5b90668
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/38:
 #0: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
6 locks held by dhcpcd/5468:
2 locks held by getty/5557:
 #0: ffff888037c350a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90003cbe2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211
5 locks held by syz-executor/5805:
3 locks held by udevd/6003:
1 lock held by syz.2.435/8325:
 #0: ffff888061b800d0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
 #0: ffff888061b800d0 (&type->s_umount_key#71){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
1 lock held by syz.3.661/10997:
3 locks held by syz.1.662/11007:
2 locks held by syz.5.663/11011:
2 locks held by syz.7.665/11017:

=============================================

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 03/18/2026
Call Trace:
 <TASK>
 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:162 [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:353 [inline]
 watchdog+0xfd3/0x1030 kernel/hung_task.c:561
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 11017 Comm: syz.7.665 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:_raw_spin_unlock_irqrestore+0x6/0x80 kernel/locking/spinlock.c:197
Code: 3f 05 f6 5b c3 cc cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 56 <53> 48 89 f3 49 89 fe 48 83 c7 18 48 8b 74 24 10 e8 15 70 72 f6 4c
RSP: 0000:ffffc9001da57710 EFLAGS: 00000002
RAX: 0000000000000002 RBX: ffffc9001da57768 RCX: ffffffff997cc303
RDX: 0000000000000001 RSI: 0000000000000246 RDI: ffff888063ab9ad0
RBP: ffffc9001da577d0 R08: ffff888063ab9b27 R09: 1ffff1100c757364
R10: dffffc0000000000 R11: ffffed100c757365 R12: 1ffff92003b4aeed
R13: 0000000000000246 R14: ffff888063ab9ad0 R15: ffffc9001da57760
FS:  00007fa70c5ae6c0(0000) GS:ffff888126209000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa1ecd69000 CR3: 000000006e814000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 raw_spin_unlock_irqrestore_wake include/linux/sched/wake_q.h:97 [inline]
 rtlock_slowlock kernel/locking/rtmutex.c:1912 [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_irq include/linux/spinlock_rt.h:96 [inline]
 shmem_add_to_page_cache+0x74a/0xbf0 mm/shmem.c:904
 shmem_alloc_and_add_folio mm/shmem.c:2001 [inline]
 shmem_get_folio_gfp+0x7e9/0x1a80 mm/shmem.c:2564
 shmem_get_folio mm/shmem.c:2670 [inline]
 shmem_write_begin+0x166/0x320 mm/shmem.c:3323
 generic_perform_write+0x2af/0x8b0 mm/filemap.c:4324
 shmem_file_write_iter+0xfb/0x120 mm/shmem.c:3498
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x629/0xba0 fs/read_write.c:688
 ksys_write+0x156/0x270 fs/read_write.c:740
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa70e31d04e
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007fa70c5adda8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fa70c5ae6c0 RCX: 00007fa70e31d04e
RDX: 0000000001000000 RSI: 00007fa70418e000 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004
R13: 00007fa70c5adee0 R14: 00007fa70c5adea0 R15: 00007fa70418e000
 </TASK>