syzbot

INFO: task syz-executor:4309 blocked for more than 143 seconds.
      Not tainted 5.15.188-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:21768 pid: 4309 ppid:     1 flags:0x00004004
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
 io_schedule+0x7c/0xd0 kernel/sched/core.c:8484
 wait_on_page_bit_common+0x815/0xe00 mm/filemap.c:1356
 lock_page include/linux/pagemap.h:625 [inline]
 truncate_inode_pages_range+0x97f/0xef0 mm/truncate.c:394
 evict+0x498/0x870 fs/inode.c:649
 dispose_list fs/inode.c:680 [inline]
 evict_inodes+0x604/0x690 fs/inode.c:734
 generic_shutdown_super+0x93/0x300 fs/super.c:454
 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:1139
 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: 0033:0x7f63b95e6c57
RSP: 002b:00007ffe31f2f328 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f63b9667a8d RCX: 00007f63b95e6c57
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe31f2f3e0
RBP: 00007ffe31f2f3e0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe31f30470
R13: 00007f63b9667a8d R14: 00000000000228e1 R15: 00007ffe31f304b0
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c11c360 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by kworker/u4:5/3093:
 #0: ffff8880b903a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
 #1: ffff8880b9027848 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x4d6/0x810 kernel/sched/psi.c:891
2 locks held by getty/3948:
 #0: ffff88802c1de098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002cf62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158
1 lock held by syz-executor/4309:
 #0: ffff88802bbe80e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
1 lock held by syz-executor/4329:
 #0: ffff8880199da0e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
1 lock held by syz-executor/4355:
 #0: ffff8880233160e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
1 lock held by syz-executor/4377:
 #0: ffff88807bed40e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
1 lock held by syz-executor/4398:
 #0: ffff8880226100e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
1 lock held by syz-executor/4431:
 #0: ffff88805acc40e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
1 lock held by syz-executor/4459:
 #0: ffff88805be100e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
1 lock held by syz-executor/4487:
 #0: ffff88805bba80e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.188-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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 154 Comm: kworker/u4:2 Not tainted 5.15.188-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue:  0x0 (phy12)
RIP: 0010:__list_add_valid+0x0/0xe0 lib/list_debug.c:22
Code: ff 44 89 e1 80 e1 07 80 c1 03 38 c1 0f 8c 10 ff ff ff 4c 89 e7 e8 c0 7b dd fd e9 03 ff ff ff e8 56 02 98 fd 0f 0b 00 00 cc cc <41> 57 41 56 41 55 41 54 53 48 85 f6 0f 84 8a 00 00 00 48 89 d3 48
RSP: 0018:ffffc90001fc7d70 EFLAGS: 00000046
RAX: 1ffff11003acd00c RBX: 1ffff11003acd000 RCX: dffffc0000000000
RDX: ffff888023849500 RSI: ffff888016879870 RDI: ffff88801d668000
RBP: ffff888016879800 R08: dffffc0000000000 R09: ffff88801d668010
R10: ffffed1003acd005 R11: 1ffff11003acd002 R12: ffff888016879870
R13: ffff888023849500 R14: 1ffff11002d0f30e R15: ffff88801d668000
FS:  0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffe11f1e48 CR3: 0000000022f2d000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __list_add include/linux/list.h:67 [inline]
 list_add include/linux/list.h:86 [inline]
 worker_enter_idle+0x1a6/0x570 kernel/workqueue.c:1821
 worker_thread+0xf06/0x12a0 kernel/workqueue.c:2475
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>