syzbot

INFO: task syz-executor105:3541 blocked for more than 143 seconds.
      Not tainted 5.15.154-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor105 state:D stack:24096 pid: 3541 ppid:  3539 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1f0 kernel/sched/core.c:6459
 bit_wait+0xe/0xc0 kernel/sched/wait_bit.c:199
 __wait_on_bit+0xb9/0x180 kernel/sched/wait_bit.c:49
 out_of_line_wait_on_bit+0x1d0/0x250 kernel/sched/wait_bit.c:64
 wait_on_bit include/linux/wait_bit.h:76 [inline]
 gfs2_glock_wait+0xda/0x1c0 fs/gfs2/glock.c:1280
 gfs2_glock_nq_init fs/gfs2/glock.h:246 [inline]
 __gfs2_lookup+0x113/0x270 fs/gfs2/inode.c:882
 __lookup_slow+0x275/0x3d0 fs/namei.c:1663
 lookup_slow+0x53/0x70 fs/namei.c:1680
 walk_component+0x48c/0x610 fs/namei.c:1976
 lookup_last fs/namei.c:2431 [inline]
 path_lookupat+0x16f/0x450 fs/namei.c:2455
 filename_lookup+0x230/0x5c0 fs/namei.c:2484
 user_path_at_empty+0x40/0x180 fs/namei.c:2883
 user_path_at include/linux/namei.h:57 [inline]
 ksys_umount fs/namespace.c:1779 [inline]
 __do_sys_umount fs/namespace.c:1787 [inline]
 __se_sys_umount fs/namespace.c:1785 [inline]
 __x64_sys_umount+0xf0/0x170 fs/namespace.c:1785
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f043b8545c7
RSP: 002b:00007ffc4723d2b8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f043b8545c7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc4723d370
RBP: 00007ffc4723d370 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000206 R12: 00007ffc4723e460
R13: 0000555556fae740 R14: 0000555556f9d338 R15: 00007ffc472405e0
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c91fae0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3265:
 #0: ffff88814abe3098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002bab2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158
1 lock held by syz-executor105/3541:
 #0: ffff8880725095a8 (&type->i_mutex_dir_key#6){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:799 [inline]
 #0: ffff8880725095a8 (&type->i_mutex_dir_key#6){.+.+}-{3:3}, at: lookup_slow+0x45/0x70 fs/namei.c:1679

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.154-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 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+0xe72/0xeb0 kernel/hung_task.c:295
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:109 [inline]
NMI backtrace for cpu 0 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:570