syzbot

INFO: task kworker/1:1:44 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:1     state:D stack:22864 pid:44    tgid:44    ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: gfs2_recovery gfs2_recover_func
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
 io_schedule+0x80/0xd0 kernel/sched/core.c:7903
 folio_wait_bit_common+0x6b0/0xb90 mm/filemap.c:1317
 folio_lock include/linux/pagemap.h:1139 [inline]
 truncate_inode_pages_range+0xa77/0xda0 mm/truncate.c:433
 gfs2_find_jhead+0xd5c/0xe10 fs/gfs2/lops.c:594
 gfs2_recover_func+0x646/0x1d90 fs/gfs2/recovery.c:457
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
INFO: task syz.5.248:7349 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.248       state:D stack:24776 pid:7349  tgid:7343  ppid:6697   task_flags:0x400140 flags:0x00004006
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+0xb6/0x310 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_recover_journal+0xda/0x140 fs/gfs2/recovery.c:577
 init_journal+0x17cc/0x2260 fs/gfs2/ops_fstype.c:798
 init_inodes+0xdb/0x320 fs/gfs2/ops_fstype.c:851
 gfs2_fill_super+0x1923/0x20d0 fs/gfs2/ops_fstype.c:1253
 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1692
 gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1335
 vfs_get_tree+0x92/0x2b0 fs/super.c:1752
 do_new_mount+0x2a2/0xa30 fs/namespace.c:3810
 do_mount fs/namespace.c:4138 [inline]
 __do_sys_mount fs/namespace.c:4349 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4326
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fef3db9038a
RSP: 002b:00007fef3bdf5e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fef3bdf5ef0 RCX: 00007fef3db9038a
RDX: 000020000001f680 RSI: 0000200000000080 RDI: 00007fef3bdf5eb0
RBP: 000020000001f680 R08: 00007fef3bdf5ef0 R09: 0000000000000084
R10: 0000000000000084 R11: 0000000000000246 R12: 0000200000000080
R13: 00007fef3bdf5eb0 R14: 000000000001f81f R15: 00002000000001c0
 </TASK>
INFO: lockdep is turned off.
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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:332 [inline]
 watchdog+0xf60/0xfa0 kernel/hung_task.c:495
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 7191 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:400
Code: e8 1e 6e 6d 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 cf 17 d1 fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 cc cc cc cc cc 44 89 f9 80 e1 07
RSP: 0018:ffffc9000dce7538 EFLAGS: 00000006
RAX: 1ffffffff3401505 RBX: 00000000000003f9 RCX: 0000000000000000
RDX: 00000000000003f9 RSI: 0000000000000000 RDI: 0000000000000020
RBP: ffffc9000dce7710 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: ffffffff85532060 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffffffff9a00af20 R15: 0000000000000000
FS:  000055556baf2500(0000) GS:ffff8881259ff000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000000f000 CR3: 000000007b800000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 serial_port_in include/linux/serial_core.h:806 [inline]
 serial8250_console_write+0x581/0x1ba0 drivers/tty/serial/8250/8250_port.c:3306
 console_emit_next_record kernel/printk/printk.c:3138 [inline]
 console_flush_all+0x725/0xc40 kernel/printk/printk.c:3226
 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
 console_unlock+0xc4/0x270 kernel/printk/printk.c:3325
 vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450
 _printk+0xcf/0x120 kernel/printk/printk.c:2475
 __ext4_msg+0x293/0x2a0 fs/ext4/super.c:981
 ext4_put_super+0xb8/0xc40 fs/ext4/super.c:1286
 generic_shutdown_super+0x135/0x2c0 fs/super.c:643
 kill_block_super+0x44/0x90 fs/super.c:1723
 ext4_kill_sb+0x68/0xb0 fs/ext4/super.c:7395
 deactivate_locked_super+0xb9/0x130 fs/super.c:474
 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1375
 task_work_run+0x1d4/0x260 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xec/0x130 kernel/entry/common.c:43
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f716818ff17
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffc8f6a2d78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f7168211c05 RCX: 00007f716818ff17
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc8f6a2e30
RBP: 00007ffc8f6a2e30 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc8f6a3ec0
R13: 00007f7168211c05 R14: 0000000000046dbb R15: 00007ffc8f6a3f00
 </TASK>