syzbot

INFO: task syz-executor403:4193 blocked for more than 143 seconds.
      Not tainted 5.15.182-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor403 state:D
 stack:26784 pid: 4193 ppid:  4190 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1e0 kernel/sched/core.c:6459
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
 gfs2_gl_hash_clear+0x1a4/0x2f0 fs/gfs2/glock.c:2183
 gfs2_put_super+0x769/0x7d0 fs/gfs2/super.c:624
 generic_shutdown_super+0x130/0x300 fs/super.c:475
 kill_block_super+0x7c/0xe0 fs/super.c:1427
 deactivate_locked_super+0x93/0xf0 fs/super.c:335
 cleanup_mnt+0x418/0x4d0 fs/namespace.c:1143
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0x10f/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+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fd53f7485b7
RSP: 002b:00007fffda1ad2f8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000020723 RCX: 00007fd53f7485b7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fffda1ad3b0
RBP: 00007fffda1ad3b0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000202 R12: 00007fffda1ae420
R13: 000055557f56d6c0 R14: 431bde82d7b634db R15: 00007fffda1ae440
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c11bea0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3938:
 #0: ffff88802c1b4098 (&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+0x5ba/0x1a30 drivers/tty/n_tty.c:2158
1 lock held by syz-executor403/4192:
 #0: ffff88802091a118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x157/0xa60 block/bdev.c:820
1 lock held by syz-executor403/4193:
 #0: ffff888072c640e0 (&type->s_umount_key#43){++++}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
2 locks held by udevd/4203:
 #0: ffff88802091a118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915
 #1: ffff888147557468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xaa/0xb90 drivers/block/loop.c:1366
3 locks held by kworker/1:4/4284:
 #0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc9000311fd00 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
 #2: ffffffff8c120928 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #2: ffffffff8c120928 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x347/0x6b0 kernel/rcu/tree_exp.h:845
1 lock held by syz-executor403/4532:
 #0: ffff888147575468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xaa/0xb90 drivers/block/loop.c:1366
1 lock held by syz-executor403/4533:
 #0: ffff888147554468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xaa/0xb90 drivers/block/loop.c:1366
1 lock held by syz-executor403/4534:

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.182-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 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+0xe0f/0xe50 kernel/hung_task.c:369
 kthread+0x436/0x520 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
CPU: 0 PID: 4534 Comm: syz-executor403 Not tainted 5.15.182-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
RIP: 0010:asm_exc_page_fault+0x0/0x30 arch/x86/include/asm/idtentry.h:605
Code: 74 24 28 ff 74 24 28 ff 74 24 28 ff 74 24 28 e8 a6 05 00 00 48 89 c4 48 89 e7 e8 bb fb e0 ff e9 86 06 00 00 90 90 90 90 90 90 <0f> 01 ca fc e8 87 05 00 00 48 89 c4 48 89 e7 48 8b 74 24 78 48 c7
RSP: 0000:fffffe0000002fd0 EFLAGS: 00000006
RAX: 0000000000acb001 RBX: 00007fffda1ad980 RCX: 00000000000000ed
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00007fffda1ada20
RBP: 0000000000000102 R08: 00007fd537308000 R09: 0000000000acb000
R10: 0000000000000000 R11: 00007fffda1ad990 R12: 0000000000000001
R13: 00007fd53f7a28c0 R14: 0000000000000000 R15: 00007fffda1ada20
FS:  000055557f56c380(0000) GS:ffff8880b9000000(0000) knlGS:ffff8880b9000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd537dd3000 CR3: 000000001f4cd000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <ENTRY_TRAMPOLINE>
RIP: 0033:0x7fd53f711b86
RSP: 002b:00007fffda1ad8e0 EFLAGS: 00010206
 </ENTRY_TRAMPOLINE>