syzbot

INFO: task syz-executor359:5091 blocked for more than 143 seconds.
      Not tainted 6.9.0-rc3-next-20240411-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor359 state:D stack:24984 pid:5091  tgid:5091  ppid:5088   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5409 [inline]
 __schedule+0x17e8/0x4a50 kernel/sched/core.c:6746
 __schedule_loop kernel/sched/core.c:6823 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6838
 bit_wait+0x12/0xd0 kernel/sched/wait_bit.c:199
 __wait_on_bit+0xb0/0x2f0 kernel/sched/wait_bit.c:49
 out_of_line_wait_on_bit+0x1d5/0x260 kernel/sched/wait_bit.c:64
 wait_on_bit include/linux/wait_bit.h:76 [inline]
 gfs2_glock_wait+0xc7/0x2b0 fs/gfs2/glock.c:1344
 gfs2_glock_nq_init fs/gfs2/glock.h:238 [inline]
 __gfs2_lookup+0x11b/0x280 fs/gfs2/inode.c:905
 __lookup_slow+0x28c/0x3f0 fs/namei.c:1692
 lookup_slow+0x53/0x70 fs/namei.c:1709
 walk_component+0x2e1/0x410 fs/namei.c:2004
 lookup_last fs/namei.c:2461 [inline]
 path_lookupat+0x16f/0x450 fs/namei.c:2485
 filename_lookup+0x256/0x610 fs/namei.c:2514
 user_path_at_empty+0x42/0x60 fs/namei.c:2921
 user_path_at include/linux/namei.h:57 [inline]
 ksys_umount fs/namespace.c:1916 [inline]
 __do_sys_umount fs/namespace.c:1924 [inline]
 __se_sys_umount fs/namespace.c:1922 [inline]
 __x64_sys_umount+0xf4/0x170 fs/namespace.c:1922
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f83e9183587
RSP: 002b:00007fffdb5f1f68 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f83e9183587
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fffdb5f2020
RBP: 00007fffdb5f2020 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000202 R12: 00007fffdb5f3110
R13: 0000555562dbd740 R14: 0000555562dac338 R15: 00007fffdb5f5290
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/30:
 #0: ffffffff8e335ca0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
 #0: ffffffff8e335ca0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e335ca0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614
2 locks held by getty/4849:
 #0: ffff88802ad660a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002f162f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2201
1 lock held by syz-executor359/5091:
 #0: ffff888068e3d1f0 (&type->i_mutex_dir_key#6){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:801 [inline]
 #0: ffff888068e3d1f0 (&type->i_mutex_dir_key#6){.+.+}-{3:3}, at: lookup_slow+0x45/0x70 fs/namei.c:1708

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

NMI backtrace for cpu 1
CPU: 1 PID: 30 Comm: khungtaskd Not tainted 6.9.0-rc3-next-20240411-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+0x241/0x360 lib/dump_stack.c:114
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xfde/0x1020 kernel/hung_task.c:380
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4529 Comm: klogd Not tainted 6.9.0-rc3-next-20240411-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:__rb_insert_augmented+0x9/0x6b0 lib/rbtree.c:458
Code: c3 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 <41> 55 41 54 53 48 83 ec 38 48 89 54 24 08 48 89 74 24 10 48 89 fd
RSP: 0018:ffffc90004a4f518 EFLAGS: 00000086
RAX: 000000052ae920a0 RBX: ffff8880b943e6c0 RCX: dffffc0000000000
RDX: ffffffff816bbee0 RSI: ffff8880b943e710 RDI: ffff88807d890090
RBP: 1ffff1100fb12019 R08: ffff88807d8900a7 R09: 0000000000000000
R10: ffff88807d890098 R11: ffffed100fb12015 R12: ffff88802e575b18
R13: dffffc0000000000 R14: ffff88807d890080 R15: ffff88807d8900c8
FS:  00007ff2573a4380(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005617143a8600 CR3: 000000002be1e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 put_prev_entity+0x62/0x210 kernel/sched/fair.c:5493
 pick_next_task_fair+0x363/0xde0 kernel/sched/fair.c:8535
 __pick_next_task+0xb0/0x2c0 kernel/sched/core.c:6030
 pick_next_task kernel/sched/core.c:6120 [inline]
 __schedule+0x729/0x4a50 kernel/sched/core.c:6702
 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6925
 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6949
 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
 _raw_spin_unlock_irqrestore+0x130/0x140 kernel/locking/spinlock.c:194
 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
 __wake_up_common_lock+0x18c/0x1e0 kernel/sched/wait.c:108
 sock_def_readable+0x20f/0x5b0 net/core/sock.c:3353
 unix_dgram_sendmsg+0x148e/0x1f80 net/unix/af_unix.c:2113
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x221/0x270 net/socket.c:745
 __sys_sendto+0x3a4/0x4f0 net/socket.c:2191
 __do_sys_sendto net/socket.c:2203 [inline]
 __se_sys_sendto net/socket.c:2199 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2199
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff2575069b5
Code: 8b 44 24 08 48 83 c4 28 48 98 c3 48 98 c3 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 26 45 31 c9 45 31 c0 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 7a 48 8b 15 44 c4 0c 00 f7 d8 64 89 02 48 83
RSP: 002b:00007fff461d0318 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007ff2575069b5
RDX: 000000000000004e RSI: 0000556259833d70 RDI: 0000000000000003
RBP: 000055625982f910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000246 R12: 0000000000000013
R13: 00007ff257694212 R14: 00007fff461d0418 R15: 0000000000000000
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.937 msecs