syzbot

INFO: task syz-executor:5994 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:21800 pid:5994  tgid:5994  ppid:1      task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 bit_wait+0x11/0xd0 kernel/sched/wait_bit.c:240
 __wait_on_bit+0xb9/0x310 kernel/sched/wait_bit.c:52
 out_of_line_wait_on_bit+0x123/0x170 kernel/sched/wait_bit.c:67
 wait_on_bit include/linux/wait_bit.h:77 [inline]
 gfs2_glock_wait+0xbd/0x2a0 fs/gfs2/glock.c:1350
 gfs2_glock_nq_init fs/gfs2/glock.h:248 [inline]
 __gfs2_lookup+0x117/0x270 fs/gfs2/inode.c:984
 __lookup_slow+0x297/0x3d0 fs/namei.c:1808
 lookup_slow+0x53/0x70 fs/namei.c:1825
 walk_component+0x2d2/0x400 fs/namei.c:2129
 lookup_last fs/namei.c:2630 [inline]
 path_lookupat+0x163/0x430 fs/namei.c:2654
 filename_lookup+0x212/0x570 fs/namei.c:2683
 user_path_at+0x3a/0x60 fs/namei.c:3127
 ksys_umount fs/namespace.c:2112 [inline]
 __do_sys_umount fs/namespace.c:2120 [inline]
 __se_sys_umount fs/namespace.c:2118 [inline]
 __x64_sys_umount+0xee/0x160 fs/namespace.c:2118
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff27f78fed7
RSP: 002b:00007ffd173f7958 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: ffffffffffffffda RBX: 00007ff27f811c05 RCX: 00007ff27f78fed7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd173f7a10
RBP: 00007ffd173f7a10 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd173f8b00
R13: 00007ff27f811c05 R14: 0000555569db84a8 R15: 00007ffd173facc0
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5625:
 #0: ffff88814dc7e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by syz-executor/5994:
 #0: ffff88805e6d22b8 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:885 [inline]
 #0: ffff88805e6d22b8 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1824
2 locks held by syz.1.174/6716:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
 watchdog+0xf93/0xfe0 kernel/hung_task.c:491
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148
 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: 6061 Comm: udevd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:next_tid mm/slub.c:3044 [inline]
RIP: 0010:__update_cpu_freelist_fast mm/slub.c:3641 [inline]
RIP: 0010:__slab_alloc_node mm/slub.c:4085 [inline]
RIP: 0010:slab_alloc_node mm/slub.c:4228 [inline]
RIP: 0010:kmem_cache_alloc_noprof+0xef/0x3c0 mm/slub.c:4247
Code: 00 00 41 83 fc ff 74 1a 48 8b 03 48 83 f8 ff 0f 84 d3 02 00 00 48 c1 e8 3a 41 39 c4 0f 85 5d 01 00 00 41 8b 46 28 4a 8b 1c 28 <49> 8d 4f 08 49 8b 36 4c 89 e8 4c 89 fa 65 48 0f c7 0e 74 5c eb 95
RSP: 0018:ffffc900038bfe30 EFLAGS: 00000246
RAX: 0000000000000800 RBX: ffff88807b38d500 RCX: ffffffff92a2b930
RDX: 0000000000000000 RSI: 0000000000001000 RDI: ffffffff8e2596e0
RBP: 0000000000000cc0 R08: 0000000000000000 R09: ffffffff8215dcad
R10: dffffc0000000000 R11: fffffbfff1f474a7 R12: 00000000ffffffff
R13: ffff88807b38e600 R14: ffff88801b698640 R15: 00000000000d5921
FS:  00007fa137748880(0000) GS:ffff888125d15000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa137744000 CR3: 0000000077ea0000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 getname_flags+0xb8/0x540 fs/namei.c:146
 getname include/linux/fs.h:2919 [inline]
 __do_sys_rename fs/namei.c:5325 [inline]
 __se_sys_rename fs/namei.c:5323 [inline]
 __x64_sys_rename+0x5d/0x90 fs/namei.c:5323
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa13707acc7
Code: e8 5e a7 09 00 f7 d8 19 c0 5b c3 0f 1f 84 00 00 00 00 00 b8 ff ff ff ff 5b c3 66 0f 1f 84 00 00 00 00 00 b8 52 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 01 61 17 00 f7 d8 64 89 02 b8
RSP: 002b:00007ffce63fe4d8 EFLAGS: 00000206 ORIG_RAX: 0000000000000052
RAX: ffffffffffffffda RBX: 0000555e0ab2ff60 RCX: 00007fa13707acc7
RDX: 0000555e0ab0f010 RSI: 00007ffce63fe4f0 RDI: 00007ffce63fe8f0
RBP: 0000555e0ab27e00 R08: 00000000000001e0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 00007ffce63fe4f0
R13: 00007ffce63fe8f0 R14: 0000000000000000 R15: 0000555df1adf9dd
 </TASK>