syzbot

INFO: task syz-executor:4298 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:21824 pid: 4298 ppid:     1 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 io_schedule+0x7c/0xd0 kernel/sched/core.c:8503
 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:1148
 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+0xee/0x180 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: 0033:0x7ff29b47f2f7
RSP: 002b:00007ffdc7c02908 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007ff29b47f2f7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffdc7c029c0
RBP: 00007ffdc7c029c0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffdc7c03a50
R13: 00007ff29b500d7d R14: 0000000000014829 R15: 00007ffdc7c03a90
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c11c760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by kworker/u4:3/589:
 #0: ffff8880b903a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
 #1: ffff8880b9027888 (&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/3953:
 #0: ffff88802b195098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc900025ce2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158
1 lock held by syz-executor/4298:
 #0: ffff88807bfc60e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
1 lock held by syz-executor/4356:
 #0: ffff88801ea2a0e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
1 lock held by syz-executor/4385:
 #0: ffff88807d2680e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
1 lock held by syz-executor/4405:
 #0: ffff8880244200e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
1 lock held by syz-executor/4426:
 #0: ffff88805bbc60e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
1 lock held by syz-executor/4459:
 #0: ffff88805796e0e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
1 lock held by syz-executor/4487:
 #0: ffff888058e040e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
1 lock held by syz-executor/4514:
 #0: ffff888058e3c0e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
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
CPU: 0 PID: 1236 Comm: kworker/u4:4 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:35 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:106 [inline]
RIP: 0010:lock_release+0x13c/0x870 kernel/locking/lockdep.c:5639
Code: c0 0f 85 28 05 00 00 41 83 3e 00 0f 85 58 04 00 00 48 89 5c 24 18 48 c7 84 24 a0 00 00 00 00 00 00 00 9c 8f 84 24 a0 00 00 00 <48> 8b 84 24 a0 00 00 00 48 89 44 24 50 fa 48 c7 c7 60 2a 0b 8a e8
RSP: 0018:ffffc90004d7fa00 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff88802135bb80 RCX: 2612be134418c100
RDX: 0000000000000000 RSI: ffffffff8a59e560 RDI: ffffffff8a59e520
RBP: ffffc90004d7fb20 R08: dffffc0000000000 R09: fffffbfff1ad33a6
R10: fffffbfff1ad33a6 R11: 1ffffffff1ad33a5 R12: ffff88805997f0d8
R13: dffffc0000000000 R14: ffff88802135c66c R15: 1ffff920009aff4c
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000557a079e1660 CR3: 000000007e18e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:174 [inline]
 _raw_spin_unlock_bh+0x17/0x30 kernel/locking/spinlock.c:210
 spin_unlock_bh include/linux/spinlock.h:409 [inline]
 batadv_nc_purge_paths+0x316/0x3b0 net/batman-adv/network-coding.c:475
 batadv_nc_worker+0x2e7/0x5c0 net/batman-adv/network-coding.c:724
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>