syzbot

INFO: task syz-executor352:4168 blocked for more than 143 seconds.
      Not tainted 5.15.184-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor352 state:D stack:26048 pid: 4168 ppid:  4166 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_preempt_disabled+0xf/0x20 kernel/sched/core.c:6518
 __mutex_lock_common+0xc71/0x2390 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 lmLogClose+0xb0/0x520 fs/jfs/jfs_logmgr.c:1452
 jfs_umount+0x28f/0x360 fs/jfs/jfs_umount.c:116
 jfs_put_super+0x88/0x190 fs/jfs/super.c:194
 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: 0033:0x7f6931b6a837
RSP: 002b:00007ffc5939de58 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 000000000000f4af RCX: 00007f6931b6a837
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc5939df10
RBP: 00007ffc5939df10 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000202 R12: 00007ffc5939ef80
R13: 000055556585e6c0 R14: 431bde82d7b634db R15: 00007ffc5939efa0
 </TASK>
INFO: task syz-executor352:4169 blocked for more than 143 seconds.
      Not tainted 5.15.184-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor352 state:D stack:25056 pid: 4169 ppid:  4166 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_preempt_disabled+0xf/0x20 kernel/sched/core.c:6518
 __mutex_lock_common+0xc71/0x2390 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 lmLogClose+0xb0/0x520 fs/jfs/jfs_logmgr.c:1452
 jfs_umount+0x28f/0x360 fs/jfs/jfs_umount.c:116
 jfs_put_super+0x88/0x190 fs/jfs/super.c:194
 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: 0033:0x7f6931b6a837
RSP: 002b:00007ffc5939de58 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 000000000000f4a6 RCX: 00007f6931b6a837
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc5939df10
RBP: 00007ffc5939df10 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000202 R12: 00007ffc5939ef80
R13: 000055556585e6c0 R14: 431bde82d7b634db R15: 00007ffc5939efa0
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c11c060 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3936:
 #0: ffff88814cb17098 (&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
2 locks held by syz-executor352/4168:
 #0: ffff88807a4320e0 (&type->s_umount_key#43){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
 #1: ffffffff8c4c40a8 (jfs_log_mutex){+.+.}-{3:3}, at: lmLogClose+0xb0/0x520 fs/jfs/jfs_logmgr.c:1452
2 locks held by syz-executor352/4169:
 #0: ffff888019dcc0e0 (&type->s_umount_key#43){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
 #1: ffffffff8c4c40a8 (jfs_log_mutex){+.+.}-{3:3}, at: lmLogClose+0xb0/0x520 fs/jfs/jfs_logmgr.c:1452
2 locks held by syz-executor352/4170:
 #0: ffff88801eaa20e0 (&type->s_umount_key#43){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
 #1: ffffffff8c4c40a8 (jfs_log_mutex){+.+.}-{3:3}, at: lmLogClose+0xb0/0x520 fs/jfs/jfs_logmgr.c:1452
2 locks held by syz-executor352/4171:
 #0: ffff88807e0a60e0 (&type->s_umount_key#43){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
 #1: ffffffff8c4c40a8 (jfs_log_mutex){+.+.}-{3:3}, at: lmLogClose+0xb0/0x520 fs/jfs/jfs_logmgr.c:1452
1 lock held by syz-executor352/4172:
 #0: ffff88807634a0e0 (&type->s_umount_key#43){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.184-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 0 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:722