syzbot

INFO: task syz-executor862:21862 blocked for more than 143 seconds.
      Not tainted 5.15.103-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor862 state:D stack:28032 pid:21862 ppid:  3658 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5023 [inline]
 __schedule+0x1348/0x4610 kernel/sched/core.c:6369
 schedule+0x11b/0x1f0 kernel/sched/core.c:6452
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6511
 rwsem_down_read_slowpath+0x605/0xb40 kernel/locking/rwsem.c:1047
 __down_read_common+0x61/0x2c0 kernel/locking/rwsem.c:1231
 iterate_supers+0xac/0x1e0 fs/super.c:694
 ksys_sync+0xb9/0x1c0 fs/sync.c:102
 __do_sys_sync+0xa/0x10 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f4efe5e5db9
RSP: 002b:00007f4efdd73208 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f4efe675298 RCX: 00007f4efe5e5db9
RDX: 00007f4efe5e5db9 RSI: 00007f4efe63c1b4 RDI: 0000000000000081
RBP: 00007f4efe675290 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4efe67529c
R13: 00007ffca4092d0f R14: 00007f4efdd73300 R15: 0000000000022000
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c91c320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
1 lock held by klogd/2949:
 #0: ffff8880b9b39698 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
2 locks held by getty/3270:
 #0: ffff8880241fc098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002bb32e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1da0 drivers/tty/n_tty.c:2147
1 lock held by syz-executor862/21861:
 #0: ffff88801bd7c0e0 (&type->s_umount_key#44/1){+.+.}-{3:3}, at: alloc_super+0x210/0x940 fs/super.c:229
1 lock held by syz-executor862/21862:
 #0: ffff88801bd7c0e0 (&type->s_umount_key#67){.+.+}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:694

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.103-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xf54/0xfa0 kernel/hung_task.c:295
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:109 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:570