syzbot

INFO: task syz-executor:5964 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:21672 pid:5964  tgid:5964  ppid:1      task_flags:0x400140 flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7026
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
 lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443
 jfs_umount+0x2ef/0x3c0 fs/jfs/jfs_umount.c:114
 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194
 generic_shutdown_super+0x135/0x2c0 fs/super.c:642
 kill_block_super+0x44/0x90 fs/super.c:1729
 deactivate_locked_super+0xbc/0x130 fs/super.c:473
 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1318
 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+0xe9/0x130 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: 0033:0x7fd4b1390a77
RSP: 002b:00007ffe63d38d68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fd4b1413d7d RCX: 00007fd4b1390a77
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe63d38e20
RBP: 00007ffe63d38e20 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe63d39eb0
R13: 00007fd4b1413d7d R14: 0000000000036901 R15: 00007ffe63d39ef0
 </TASK>
INFO: task syz-executor:5966 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:21752 pid:5966  tgid:5966  ppid:1      task_flags:0x400140 flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7026
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
 lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443
 jfs_umount+0x2ef/0x3c0 fs/jfs/jfs_umount.c:114
 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194
 generic_shutdown_super+0x135/0x2c0 fs/super.c:642
 kill_block_super+0x44/0x90 fs/super.c:1729
 deactivate_locked_super+0xbc/0x130 fs/super.c:473
 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1318
 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+0xe9/0x130 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: 0033:0x7f06e7390a77
RSP: 002b:00007ffff8baf6c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f06e7413d7d RCX: 00007f06e7390a77
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffff8baf780
RBP: 00007ffff8baf780 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffff8bb0810
R13: 00007f06e7413d7d R14: 0000000000036e2d R15: 00007ffff8bb0850
 </TASK>
INFO: task syz-executor:5983 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:21608 pid:5983  tgid:5983  ppid:1      task_flags:0x400140 flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7026
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
 lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443
 jfs_umount+0x2ef/0x3c0 fs/jfs/jfs_umount.c:114
 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194
 generic_shutdown_super+0x135/0x2c0 fs/super.c:642
 kill_block_super+0x44/0x90 fs/super.c:1729
 deactivate_locked_super+0xbc/0x130 fs/super.c:473
 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1318
 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+0xe9/0x130 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: 0033:0x7fe5e2390a77
RSP: 002b:00007ffe03d6df08 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fe5e2413d7d RCX: 00007fe5e2390a77
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe03d6dfc0
RBP: 00007ffe03d6dfc0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe03d6f050
R13: 00007fe5e2413d7d R14: 0000000000036d1f R15: 00007ffe03d6f090
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8df3d6e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8df3d6e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8df3d6e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5582:
 #0: ffff88814d6cd0a0 (&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
2 locks held by syz-executor/5964:
 #0: ffff888027e480e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff888027e480e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff888027e480e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
 #1: ffffffff8e37c368 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443
2 locks held by syz-executor/5966:
 #0: ffff88802a4100e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff88802a4100e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff88802a4100e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
 #1: ffffffff8e37c368 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443
2 locks held by syz-executor/5971:
 #0: ffff88804be900e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff88804be900e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff88804be900e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
 #1: ffffffff8e37c368 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443
2 locks held by syz-executor/5983:
 #0: ffff88804ac5e0e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff88804ac5e0e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff88804ac5e0e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
 #1: ffffffff8e37c368 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443
2 locks held by syz-executor/6138:
 #0: ffff88805bf200e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff88805bf200e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff88805bf200e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
 #1: ffffffff8e37c368 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443
2 locks held by syz-executor/6154:
 #0: ffff88807eb640e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff88807eb640e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff88807eb640e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
 #1: ffffffff8e37c368 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443
2 locks held by syz-executor/6174:
 #0: ffff88807846e0e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff88807846e0e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff88807846e0e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
 #1: ffffffff8e37c368 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443
2 locks held by syz-executor/6179:
 #0: ffff88805892a0e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff88805892a0e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff88805892a0e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
 #1: ffffffff8e37c368 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443
2 locks held by syz-executor/6181:
 #0: ffff8880511700e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff8880511700e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff8880511700e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
 #1: ffffffff8e37c368 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443
1 lock held by syz-executor/6365:
 #0: ffff888033f820e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff888033f820e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff888033f820e0 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
2 locks held by syz.7.648/7066:
2 locks held by syz.0.650/7068:
2 locks held by syz.1.651/7069:
2 locks held by syz.2.652/7070:
2 locks held by syz.6.653/7071:

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

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 10/25/2025
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+0x4bc/0x870 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: 23 Comm: ksoftirqd/1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline]
RIP: 0010:lock_release+0x27f/0x3e0 kernel/locking/lockdep.c:5891
Code: 89 c5 7f d0 4c 89 ff 4c 89 f6 48 8b 54 24 18 e8 57 30 00 00 48 8b 5c 24 08 48 c7 c7 f0 61 8f 8d e8 66 67 a9 09 b8 ff ff ff ff <65> 0f c1 05 69 5b d1 10 83 f8 01 75 51 48 c7 44 24 20 00 00 00 00
RSP: 0018:ffffc900001d7390 EFLAGS: 00000082
RAX: 00000000ffffffff RBX: 0000000000000202 RCX: cd488cf44554d000
RDX: 0000000000000001 RSI: ffffffff8d8f61f0 RDI: ffffffff8bbf0960
RBP: ffff88801ca8e618 R08: ffffc900001d7527 R09: ffffc900001d7518
R10: dffffc0000000000 R11: fffff5200003aea5 R12: 0000000000000001
R13: 0000000000000001 R14: ffffffff8df3d6e0 R15: ffff88801ca8dac0
FS:  0000000000000000(0000) GS:ffff888126238000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055558fb08808 CR3: 000000005901e000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 rcu_lock_release include/linux/rcupdate.h:341 [inline]
 rcu_read_unlock include/linux/rcupdate.h:897 [inline]
 class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
 unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 __kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587
 kasan_save_free_info mm/kasan/kasan.h:406 [inline]
 poison_slab_object mm/kasan/common.c:252 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284
 kasan_slab_free include/linux/kasan.h:234 [inline]
 slab_free_hook mm/slub.c:2543 [inline]
 slab_free mm/slub.c:6642 [inline]
 kmem_cache_free+0x19b/0x690 mm/slub.c:6752
 rcu_do_batch kernel/rcu/tree.c:2605 [inline]
 rcu_core+0xcab/0x1770 kernel/rcu/tree.c:2861
 handle_softirqs+0x286/0x870 kernel/softirq.c:622
 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:1063
 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>