syzbot

INFO: task kworker/0:0:9 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:0     state:D stack:25400 pid:9     tgid:9     ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: gfs2_recovery gfs2_recover_func
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5298 [inline]
 __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911
 __schedule_loop kernel/sched/core.c:6993 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7008
 io_schedule+0x7f/0xd0 kernel/sched/core.c:7835
 folio_wait_bit_common+0x6d8/0xbc0 mm/filemap.c:1323
 folio_wait_locked include/linux/pagemap.h:1234 [inline]
 gfs2_jhead_process_page+0x175/0x670 fs/gfs2/lops.c:470
 gfs2_find_jhead+0xbd2/0xd30 fs/gfs2/lops.c:586
 gfs2_recover_func+0x6cf/0x1f60 fs/gfs2/recovery.c:459
 process_one_work kernel/workqueue.c:3276 [inline]
 process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
INFO: task syz.0.17:6054 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17        state:D stack:24952 pid:6054  tgid:6054  ppid:5980   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5298 [inline]
 __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911
 __schedule_loop kernel/sched/core.c:6993 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7008
 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+0x13b/0x190 kernel/sched/wait_bit.c:67
 wait_on_bit include/linux/wait_bit.h:77 [inline]
 gfs2_recover_journal+0xda/0x140 fs/gfs2/recovery.c:579
 init_journal+0x16ad/0x22b0 fs/gfs2/ops_fstype.c:794
 init_inodes+0xdb/0x320 fs/gfs2/ops_fstype.c:844
 gfs2_fill_super+0x1a38/0x21d0 fs/gfs2/ops_fstype.c:1250
 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694
 gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1332
 vfs_get_tree+0x92/0x2a0 fs/super.c:1754
 fc_mount fs/namespace.c:1193 [inline]
 do_new_mount_fc fs/namespace.c:3763 [inline]
 do_new_mount+0x341/0xd30 fs/namespace.c:3839
 do_mount fs/namespace.c:4172 [inline]
 __do_sys_mount fs/namespace.c:4361 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4338
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f931079da8a
RSP: 002b:00007fff9bf1d5d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fff9bf1d660 RCX: 00007f931079da8a
RDX: 00002000000003c0 RSI: 0000200000037f80 RDI: 00007fff9bf1d620
RBP: 00002000000003c0 R08: 00007fff9bf1d660 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000037f80
R13: 00007fff9bf1d620 R14: 0000000000037fa5 R15: 0000200000000000
 </TASK>

Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
 #0: ffffffff8e7648b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
 #0: ffffffff8e7648b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
2 locks held by kworker/0:0/9:
 #0: ffff88801e3d8548 ((wq_completion)gfs2_recovery){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
 #0: ffff88801e3d8548 ((wq_completion)gfs2_recovery){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
 #1: ffffc900000e7c40 ((work_completion)(&jd->jd_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
 #1: ffffc900000e7c40 ((work_completion)(&jd->jd_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359
1 lock held by khungtaskd/32:
 #0: ffffffff8e75e5a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 #0: ffffffff8e75e5a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
 #0: ffffffff8e75e5a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5575:
 #0: ffff8880329400a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000331e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211
1 lock held by syz.0.17/6054:
 #0: ffff88807dcba0e0 (&type->s_umount_key#53/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xab0 fs/super.c:345
4 locks held by syz.1.175/6608:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 32 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
 watchdog+0xfd9/0x1030 kernel/hung_task.c:515
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 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: 6608 Comm: syz.1.175 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:401
Code: e8 0e 59 84 fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 3f ab ee fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 f5 d9 ce fb cc 44 89 f9 80 e1 07
RSP: 0018:ffffc900054070d0 EFLAGS: 00000002
RAX: 1ffffffff34bb500 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020
RBP: ffffffff9a5db150 R08: ffff888025cc8237 R09: 1ffff11004b99046
R10: dffffc0000000000 R11: ffffffff85416690 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff9a5daec0 R15: 0000000000000000
FS:  0000555581875500(0000) GS:ffff888125554000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff901d70000 CR3: 000000001b3cc000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 serial_in drivers/tty/serial/8250/8250.h:128 [inline]
 serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline]
 wait_for_lsr+0x1a1/0x2f0 drivers/tty/serial/8250/8250_port.c:1970
 serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3207 [inline]
 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3272 [inline]
 serial8250_console_write+0x1348/0x1ba0 drivers/tty/serial/8250/8250_port.c:3357
 console_emit_next_record kernel/printk/printk.c:3183 [inline]
 console_flush_one_record kernel/printk/printk.c:3269 [inline]
 console_flush_all+0x718/0xb20 kernel/printk/printk.c:3343
 __console_flush_and_unlock kernel/printk/printk.c:3373 [inline]
 console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3413
 vprintk_emit+0x485/0x560 kernel/printk/printk.c:2479
 _printk+0xdd/0x130 kernel/printk/printk.c:2504
 sysfs_warn_dup fs/sysfs/dir.c:29 [inline]
 sysfs_create_dir_ns+0x26c/0x2a0 fs/sysfs/dir.c:63
 create_dir lib/kobject.c:73 [inline]
 kobject_add_internal+0x62b/0xd00 lib/kobject.c:240
 kobject_add_varg lib/kobject.c:374 [inline]
 kobject_init_and_add+0x12b/0x1a0 lib/kobject.c:457
 gfs2_sys_fs_add+0x257/0x480 fs/gfs2/sys.c:725
 gfs2_fill_super+0x13a7/0x21d0 fs/gfs2/ops_fstype.c:1201
 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694
 gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1332
 vfs_get_tree+0x92/0x2a0 fs/super.c:1754
 fc_mount fs/namespace.c:1193 [inline]
 do_new_mount_fc fs/namespace.c:3763 [inline]
 do_new_mount+0x341/0xd30 fs/namespace.c:3839
 do_mount fs/namespace.c:4172 [inline]
 __do_sys_mount fs/namespace.c:4361 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4338
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa910f9da8a
Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffcadaff9a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffcadaffa30 RCX: 00007fa910f9da8a
RDX: 00002000000003c0 RSI: 0000200000037f80 RDI: 00007ffcadaff9f0
RBP: 00002000000003c0 R08: 00007ffcadaffa30 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000037f80
R13: 00007ffcadaff9f0 R14: 0000000000037fa5 R15: 0000200000000000
 </TASK>