syzbot

INFO: task syz-executor:5949 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:21160 pid:5949  tgid:5949  ppid:1      task_flags:0x400140 flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7307
 rt_mutex_slowlock_block+0x5ba/0x6d0 kernel/locking/rtmutex.c:1647
 __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
 __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline]
 rt_mutex_slowlock+0x2b1/0x6e0 kernel/locking/rtmutex.c:1800
 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
 __mutex_lock_common kernel/locking/rtmutex_api.c:536 [inline]
 mutex_lock_nested+0x16a/0x1d0 kernel/locking/rtmutex_api.c:547
 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+0x132/0x2c0 fs/super.c:642
 kill_block_super+0x44/0x90 fs/super.c:1722
 deactivate_locked_super+0xbc/0x130 fs/super.c:473
 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1327
 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: 0033:0x7fd044b901f7
RSP: 002b:00007ffc7c6ca068 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fd044c11d7d RCX: 00007fd044b901f7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc7c6ca120
RBP: 00007ffc7c6ca120 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc7c6cb1b0
R13: 00007fd044c11d7d R14: 000000000003f832 R15: 00007ffc7c6cb1f0
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/38:
 #0: ffffffff8d7aa500 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8d7aa500 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8d7aa500 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
5 locks held by kworker/u8:3/57:
2 locks held by getty/5557:
 #0: ffff88823bf248a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90003e932e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1400 drivers/tty/n_tty.c:2222
2 locks held by syz-executor/5947:
 #0: ffff888054b680d0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff888054b680d0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff888054b680d0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
 #1: ffffffff8dbe1d78 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443
1 lock held by syz-executor/5948:
 #0: ffffffff8ea77b78 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
 #0: ffffffff8ea77b78 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3436
2 locks held by syz-executor/5949:
 #0: ffff88805a6c60d0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff88805a6c60d0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff88805a6c60d0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
 #1: ffffffff8dbe1d78 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443
2 locks held by syz-executor/6127:
 #0: ffff888036cda0d0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff888036cda0d0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff888036cda0d0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
 #1: ffffffff8dbe1d78 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443
2 locks held by syz-executor/6138:
 #0: ffff88802406e0d0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff88802406e0d0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff88802406e0d0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
 #1: ffffffff8dbe1d78 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443
2 locks held by syz-executor/6146:
 #0: ffff888059a8a0d0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff888059a8a0d0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff888059a8a0d0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
 #1: ffffffff8dbe1d78 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443
2 locks held by syz-executor/6148:
 #0: ffff8880318980d0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff8880318980d0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff8880318980d0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
 #1: ffffffff8dbe1d78 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443
2 locks held by syz-executor/6149:
 #0: ffff888039e000d0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff888039e000d0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff888039e000d0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
 #1: ffffffff8dbe1d78 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443
2 locks held by syz-executor/6263:
 #0: ffff88805b5400d0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff88805b5400d0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff88805b5400d0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
 #1: ffffffff8dbe1d78 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443
1 lock held by syz-executor/6275:
 #0: ffff888068d700d0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff888068d700d0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff888068d700d0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
1 lock held by syz.6.507/6926:
3 locks held by syz.4.509/6927:
3 locks held by syz.5.508/6928:

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
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+0x4b9/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6925 Comm: syz.3.506 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x4b/0xb0 kernel/rcu/tree.c:751
Code: 00 00 fc ff df 4c 8d 34 dd d0 5d 07 8d 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 2c 71 7b 00 48 c7 c3 d8 84 c6 91 <49> 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 75 34 8b 03 65
RSP: 0018:ffffc90005bc7098 EFLAGS: 00000246
RAX: 1ffffffff1a0ebba RBX: ffffffff91c684d8 RCX: 360e58d1458c0600
RDX: 0000000000000000 RSI: ffffffff8b3f4d40 RDI: ffffffff8b3f4d00
RBP: ffffffff81730cf5 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90005bc7278 R11: ffffffff81aa6b20 R12: 0000000000000002
R13: ffffffff8d7aa500 R14: ffffffff8d075dd0 R15: dffffc0000000000
FS:  0000555556ff8500(0000) GS:ffff888126bcb000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555ccc7fd718 CR3: 0000000023bd6000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 trace_lock_acquire include/trace/events/lock.h:24 [inline]
 lock_acquire+0x5f/0x360 kernel/locking/lockdep.c:5831
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:867 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
 unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 save_stack+0xf7/0x1f0 mm/page_owner.c:156
 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:308
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1394 [inline]
 free_unref_folios+0xc22/0x1860 mm/page_alloc.c:2963
 folios_put_refs+0x569/0x670 mm/swap.c:1002
 folio_batch_release include/linux/pagevec.h:101 [inline]
 shmem_undo_range+0x49e/0x14b0 mm/shmem.c:1120
 shmem_truncate_range mm/shmem.c:1232 [inline]
 shmem_evict_inode+0x272/0xa70 mm/shmem.c:1360
 evict+0x504/0x9c0 fs/inode.c:810
 __dentry_kill+0x209/0x660 fs/dcache.c:669
 dput+0x19f/0x2b0 fs/dcache.c:911
 __fput+0x69d/0xa80 fs/file_table.c:476
 fput_close_sync+0x119/0x200 fs/file_table.c:573
 __do_sys_close fs/open.c:1589 [inline]
 __se_sys_close fs/open.c:1574 [inline]
 __x64_sys_close+0x7f/0x110 fs/open.c:1574
 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: 0033:0x7fbbdd30db2a
Code: 48 3d 00 f0 ff ff 77 48 c3 0f 1f 80 00 00 00 00 48 83 ec 18 89 7c 24 0c e8 43 91 02 00 8b 7c 24 0c 89 c2 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 36 89 d7 89 44 24 0c e8 a3 91 02 00 8b 44 24
RSP: 002b:00007ffee543d690 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 00007fbbdd30db2a
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000000010 R08: 0000000000000000 R09: 000000000000620d
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 00007ffee543d780 R14: 00007ffee543d740 R15: 00007fbbd4577000
 </TASK>