syzbot

INFO: task syz-executor214:4185 blocked for more than 143 seconds.
      Not tainted 5.15.180-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor214 state:D stack:25176 pid: 4185 ppid:  4183 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
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914
 gfs2_gl_hash_clear+0x1a1/0x310 fs/gfs2/glock.c:2183
 gfs2_put_super+0x752/0x7c0 fs/gfs2/super.c:624
 generic_shutdown_super+0x130/0x310 fs/super.c:475
 kill_block_super+0x7a/0xe0 fs/super.c:1427
 deactivate_locked_super+0xa0/0x110 fs/super.c:335
 cleanup_mnt+0x44e/0x500 fs/namespace.c:1143
 task_work_run+0x129/0x1a0 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0x106/0x130 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f68bfd92c07
RSP: 002b:00007ffc7fa1ada8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f68bfd92c07
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc7fa1ae60
RBP: 00007ffc7fa1ae60 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000202 R12: 00007ffc7fa1bed0
R13: 00005555717d27c0 R14: 431bde82d7b634db R15: 00007ffc7fa1bef0
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8cb1f560 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3925:
 #0: ffff88814d0c1098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc900025c62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158
1 lock held by syz-executor214/4185:
 #0: ffff88807cd540e0 (&type->s_umount_key#43){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:365

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.180-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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:212 [inline]
 watchdog+0xe72/0xeb0 kernel/hung_task.c:369
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </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 default_idle+0xb/0x10 arch/x86/kernel/process.c:722