syzbot

INFO: task syz-executor:5795 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:22320 pid:5795  tgid:5795  ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x1821/0x5740 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7283
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7f7/0x1550 kernel/locking/mutex.c:820
 lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1441
 jfs_umount+0x2fb/0x3d0 fs/jfs/jfs_umount.c:124
 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194
 generic_shutdown_super+0x13d/0x2d0 fs/super.c:646
 kill_block_super+0x44/0x90 fs/super.c:1725
 deactivate_locked_super+0xbc/0x130 fs/super.c:476
 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
 exit_to_user_mode_loop+0x193/0x680 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
 do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff60c59e097
RSP: 002b:00007ffed7e52a68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007ff60c6321ca RCX: 00007ff60c59e097
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffed7e52b20
RBP: 00007ffed7e52b20 R08: 00007ffed7e53b20 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffed7e53bb0
R13: 00007ff60c6321ca R14: 000000000003b818 R15: 00007ffed7e53bf0
 </TASK>
INFO: task syz-executor:5798 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:21944 pid:5798  tgid:5798  ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x1821/0x5740 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7283
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7f7/0x1550 kernel/locking/mutex.c:820
 lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1441
 jfs_umount+0x2fb/0x3d0 fs/jfs/jfs_umount.c:124
 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194
 generic_shutdown_super+0x13d/0x2d0 fs/super.c:646
 kill_block_super+0x44/0x90 fs/super.c:1725
 deactivate_locked_super+0xbc/0x130 fs/super.c:476
 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
 exit_to_user_mode_loop+0x193/0x680 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
 do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f64cbd9e097
RSP: 002b:00007ffde4fc56b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f64cbe321ca RCX: 00007f64cbd9e097
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffde4fc5770
RBP: 00007ffde4fc5770 R08: 00007ffde4fc6770 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffde4fc6800
R13: 00007f64cbe321ca R14: 000000000003b931 R15: 00007ffde4fc6840
 </TASK>
INFO: task syz-executor:5807 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:22352 pid:5807  tgid:5807  ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x1821/0x5740 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7283
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7f7/0x1550 kernel/locking/mutex.c:820
 lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1441
 jfs_umount+0x2fb/0x3d0 fs/jfs/jfs_umount.c:124
 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194
 generic_shutdown_super+0x13d/0x2d0 fs/super.c:646
 kill_block_super+0x44/0x90 fs/super.c:1725
 deactivate_locked_super+0xbc/0x130 fs/super.c:476
 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
 exit_to_user_mode_loop+0x193/0x680 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
 do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb0be19e097
RSP: 002b:00007ffe65f686f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fb0be2321ca RCX: 00007fb0be19e097
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe65f687b0
RBP: 00007ffe65f687b0 R08: 00007ffe65f697b0 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe65f69840
R13: 00007fb0be2321ca R14: 000000000003b9ee R15: 00007ffe65f69880
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5383:
 #0: ffff888036fc70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211
2 locks held by syz-executor/5793:
 #0: ffff88807c03e0d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff88807c03e0d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
 #0: ffff88807c03e0d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508
 #1: ffffffff8edfa020 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1441
2 locks held by syz-executor/5795:
 #0: ffff8880772c60d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff8880772c60d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
 #0: ffff8880772c60d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508
 #1: ffffffff8edfa020 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1441
2 locks held by syz-executor/5798:
 #0: ffff8880787a20d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff8880787a20d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
 #0: ffff8880787a20d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508
 #1: ffffffff8edfa020 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1441
2 locks held by syz-executor/5807:
 #0: ffff888078b6a0d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff888078b6a0d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
 #0: ffff888078b6a0d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508
 #1: ffffffff8edfa020 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1441
2 locks held by syz-executor/6110:
 #0: ffff888033d120d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff888033d120d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
 #0: ffff888033d120d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508
 #1: ffffffff8edfa020 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1441
2 locks held by syz-executor/6111:
 #0: ffff88807cf440d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff88807cf440d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
 #0: ffff88807cf440d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508
 #1: ffffffff8edfa020 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1441
2 locks held by syz-executor/6147:
 #0: ffff88805a86a0d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff88805a86a0d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
 #0: ffff88805a86a0d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508
 #1: ffffffff8edfa020 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1441
2 locks held by syz-executor/6160:
 #0: ffff8880788e60d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff8880788e60d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
 #0: ffff8880788e60d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508
 #1: ffffffff8edfa020 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1441
2 locks held by syz-executor/6163:
 #0: ffff88804623c0d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff88804623c0d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
 #0: ffff88804623c0d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508
 #1: ffffffff8edfa020 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1441
1 lock held by syz-executor/6167:
 #0: ffff88805549c0d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff88805549c0d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
 #0: ffff88805549c0d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508
2 locks held by syz.1.703/7277:
2 locks held by syz.0.704/7278:
3 locks held by syz.5.705/7279:
3 locks held by syz.3.706/7280:
3 locks held by syz.6.707/7281:
2 locks held by syz.7.708/7282:

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

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 05/09/2026
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:162 [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:353 [inline]
 watchdog+0xfd3/0x1030 kernel/hung_task.c:561
 kthread+0x389/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 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: 7281 Comm: syz.6.707 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:rcu_rdp_cpu_online kernel/rcu/tree.c:4007 [inline]
RIP: 0010:rcu_lockdep_current_cpu_online+0x82/0x120 kernel/rcu/tree.c:4048
Code: c1 e8 03 42 80 3c 30 00 74 08 48 89 df e8 06 fa 85 00 48 8b 03 48 8d 98 c0 de 39 93 48 8d b8 e8 de 39 93 48 89 f8 48 c1 e8 03 <42> 80 3c 30 00 74 05 e8 e2 f9 85 00 4c 8b 7b 28 48 83 c3 20 48 89
RSP: 0018:ffffc900026377d8 EFLAGS: 00000216
RAX: 1ffff110170c77dd RBX: ffff8880b863bec0 RCX: 0000000080000001
RDX: 00000000ac4ac242 RSI: ffffffff8c28b740 RDI: ffff8880b863bee8
RBP: 1ffff1100fe058f6 R08: ffffffff8238cac8 R09: ffffffff8e95cce0
R10: dffffc0000000000 R11: fffff9400020e2b1 R12: ffffea0001071588
R13: dffffc0000000000 R14: dffffc0000000000 R15: dffffc0000000000
FS:  000055555db2e500(0000) GS:ffff88812529e000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8db5dff000 CR3: 000000007a3f5000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 rcu_read_lock_held_common kernel/rcu/update.c:113 [inline]
 rcu_read_lock_sched_held+0x1e/0x70 kernel/rcu/update.c:124
 task_css include/linux/cgroup.h:522 [inline]
 mem_cgroup_from_task+0x4d/0x120 mm/memcontrol.c:1089
 get_mem_cgroup_from_mm+0xd6/0x290 mm/memcontrol.c:1142
 __mem_cgroup_charge+0x15/0x80 mm/memcontrol.c:5037
 mem_cgroup_charge include/linux/memcontrol.h:644 [inline]
 shmem_alloc_and_add_folio+0x7cd/0xf80 mm/shmem.c:1985
 shmem_get_folio_gfp+0x5a9/0x1670 mm/shmem.c:2564
 shmem_get_folio mm/shmem.c:2670 [inline]
 shmem_write_begin+0x16c/0x330 mm/shmem.c:3303
 generic_perform_write+0x2e2/0x8f0 mm/filemap.c:4325
 shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3478
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x61d/0xb90 fs/read_write.c:688
 ksys_write+0x150/0x270 fs/read_write.c:740
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6af615d68e
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007fff67e43fc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000055555db2e500 RCX: 00007f6af615d68e
RDX: 0000000001000000 RSI: 00007f6aed200000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007fff67e44100 R14: 00007fff67e440c0 R15: 00007f6aed200000
 </TASK>