syzbot

INFO: task syz.4.2202:14605 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc3-syzkaller-00306-gaaf724ed6926 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.2202      state:D stack:25512 pid:14605 tgid:14603 ppid:13492  task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
 __schedule_loop kernel/sched/core.c:6863 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6878
 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
 ___down_common kernel/locking/semaphore.c:268 [inline]
 __down_common+0x319/0x6a0 kernel/locking/semaphore.c:293
 down+0x80/0xd0 kernel/locking/semaphore.c:100
 xfs_buf_lock+0x15d/0x4d0 fs/xfs/xfs_buf.c:996
 xfs_buf_item_unpin+0x1ce/0x6c0 fs/xfs/xfs_buf_item.c:487
 xlog_cil_ail_insert fs/xfs/xfs_log_cil.c:-1 [inline]
 xlog_cil_committed+0x7c3/0xe70 fs/xfs/xfs_log_cil.c:902
 xlog_cil_process_committed+0x15c/0x1b0 fs/xfs/xfs_log_cil.c:932
 xlog_state_shutdown_callbacks+0x269/0x360 fs/xfs/xfs_log.c:488
 xlog_force_shutdown+0x332/0x400 fs/xfs/xfs_log.c:3520
 xfs_do_force_shutdown+0x283/0x640 fs/xfs/xfs_fsops.c:517
 xfs_fs_goingdown+0x71/0x150 fs/xfs/xfs_fsops.c:-1
 xfs_file_ioctl+0x113e/0x1870 fs/xfs/xfs_ioctl.c:1378
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f29e2f8e929
RSP: 002b:00007f29e3dbb038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f29e31b5fa0 RCX: 00007f29e2f8e929
RDX: 0000200000000140 RSI: 000000008004587d RDI: 0000000000000005
RBP: 00007f29e3010b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f29e31b5fa0 R15: 00007ffc7eb795f8
 </TASK>
INFO: task syz.4.2202:14635 blocked for more than 144 seconds.
      Not tainted 6.16.0-rc3-syzkaller-00306-gaaf724ed6926 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.2202      state:D stack:26856 pid:14635 tgid:14603 ppid:13492  task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
 __schedule_loop kernel/sched/core.c:6863 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6878
 xlog_wait fs/xfs/xfs_log_priv.h:588 [inline]
 xlog_wait_on_iclog+0x4ac/0x6f0 fs/xfs/xfs_log.c:841
 xlog_force_lsn+0x4d7/0x960 fs/xfs/xfs_log.c:3045
 xfs_log_force_seq+0x1c9/0x440 fs/xfs/xfs_log.c:3082
 __xfs_trans_commit+0x7d2/0xbd0 fs/xfs/xfs_trans.c:905
 xfs_trans_commit+0x13e/0x1c0 fs/xfs/xfs_trans.c:954
 xfs_sync_sb_buf+0x134/0x230 fs/xfs/libxfs/xfs_sb.c:1474
 xfs_ioc_setlabel fs/xfs/xfs_ioctl.c:1046 [inline]
 xfs_file_ioctl+0x1536/0x1870 fs/xfs/xfs_ioctl.c:1203
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f29e2f8e929
RSP: 002b:00007f29e3d9a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f29e31b6080 RCX: 00007f29e2f8e929
RDX: 00002000000001c0 RSI: 0000000041009432 RDI: 0000000000000004
RBP: 00007f29e3010b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f29e31b6080 R15: 00007ffc7eb795f8
 </TASK>

Showing all locks held in the system:
2 locks held by kworker/0:1/10:
 #0: ffff88801a478d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff88801a478d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
 #1: ffffc900000f7bc0 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc900000f7bc0 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
1 lock held by khungtaskd/31:
 #0: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by getty/5587:
 #0: ffff8880305790a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
3 locks held by kworker/1:3/5817:
 #0: ffff88801a478d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff88801a478d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
 #1: ffffc90003cbfbc0 (key_gc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc90003cbfbc0 (key_gc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
 #2: ffffffff8e144978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline]
 #2: ffffffff8e144978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:998
5 locks held by kworker/u8:3/11749:
1 lock held by syz-executor/14601:
1 lock held by syz.4.2202/14635:
 #0: ffff888011406428 (sb_writers#22){.+.+}-{0:0}, at: mnt_want_write_file+0x60/0x200 fs/namespace.c:601
1 lock held by syz-executor/15622:
4 locks held by syz.3.2541/15926:
 #0: ffff888034b68dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:499 [inline]
 #0: ffff888034b68dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x510 net/bluetooth/hci_core.c:2717
 #1: ffff888034b680b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330 net/bluetooth/hci_sync.c:5238
 #2: ffffffff8f6777e8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2068 [inline]
 #2: ffffffff8f6777e8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x230 net/bluetooth/hci_conn.c:2560
 #3: ffff888054514338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x70/0x680 net/bluetooth/l2cap_core.c:1762

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc3-syzkaller-00306-gaaf724ed6926 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
 watchdog+0xfee/0x1030 kernel/hung_task.c:470
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 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: 0 Comm: swapper/0 Not tainted 6.16.0-rc3-syzkaller-00306-gaaf724ed6926 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 8e 4c a9 f5 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d e3 35 21 00 f3 0f 1e fa fb f4 <e9> 63 4c a9 f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8de07d80 EFLAGS: 00000286
RAX: 51beaf2993791100 RBX: ffffffff81974d58 RCX: 51beaf2993791100
RDX: 0000000000000001 RSI: ffffffff8d98204b RDI: ffffffff8be28d40
RBP: ffffffff8de07ea8 R08: ffff8880b8632f5b R09: 1ffff110170c65eb
R10: dffffc0000000000 R11: ffffed10170c65ec R12: ffffffff8fa104f0
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1bd2a50
FS:  0000000000000000(0000) GS:ffff888125c50000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000005d000 CR3: 000000000df38000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:749
 default_idle_call+0x74/0xb0 kernel/sched/idle.c:117
 cpuidle_idle_call kernel/sched/idle.c:185 [inline]
 do_idle+0x1e8/0x510 kernel/sched/idle.c:325
 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:423
 rest_init+0x2de/0x300 init/main.c:745
 start_kernel+0x47d/0x500 init/main.c:1102
 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:307
 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:288
 common_startup_64+0x13e/0x147
 </TASK>