INFO: task syz.1.2745:15859 blocked for more than 143 seconds.
Not tainted 6.16.0-rc5-next-20250711-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.2745 state:D stack:27368 pid:15859 tgid:15858 ppid:13708 task_flags:0x400140 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5314 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6697
__schedule_loop kernel/sched/core.c:6775 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6790
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6847
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x724/0xe80 kernel/locking/mutex.c:747
sync_bdevs+0x1ac/0x340 block/bdev.c:1288
ksys_sync+0xb9/0x150 fs/sync.c:105
__ia32_sys_sync+0xe/0x20 fs/sync.c:113
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: 0033:0x7f876cb8e929
RSP: 002b:00007f876dad7038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f876cdb5fa0 RCX: 00007f876cb8e929
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f876cdb5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f876cdb5fa0 R15: 00007fff08d8f9b8
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e53c5a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e53c5a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e53c5a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by dhcpcd/5519:
2 locks held by getty/5615:
#0: ffff88814d9890a0 (&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
1 lock held by udevd/10307:
#0: ffff88802552e358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945
5 locks held by kworker/1:9/13246:
#0: ffff888144a8cd48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#0: ffff888144a8cd48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3322
#1: ffffc90004267bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3215 [inline]
#1: ffffc90004267bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3322
#2: ffff888028532198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
#2: ffff888028532198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a00 drivers/usb/core/hub.c:5894
#3: ffff888028535518 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3251 [inline]
#3: ffff888028535518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5463 [inline]
#3: ffff888028535518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5706 [inline]
#3: ffff888028535518 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5866 [inline]
#3: ffff888028535518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x21a3/0x4a00 drivers/usb/core/hub.c:5948
#4: ffff8880284a9868 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline]
#4: ffff8880284a9868 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5706 [inline]
#4: ffff8880284a9868 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5866 [inline]
#4: ffff8880284a9868 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x21cb/0x4a00 drivers/usb/core/hub.c:5948
1 lock held by syz.1.2745/15859:
#0: ffff88802552e358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ac/0x340 block/bdev.c:1288
1 lock held by syz.4.3480/18358:
#0: ffff88802552e358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ac/0x340 block/bdev.c:1288
2 locks held by dhcpcd/19043:
#0: ffff88805e750258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1667 [inline]
#0: ffff88805e750258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcd0 net/packet/af_packet.c:3252
#1: ffffffff8e5420f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#1: ffffffff8e5420f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:967
2 locks held by sed/19048:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc5-next-20250711-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
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:328 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:491
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 19053 Comm: dhcpcd-run-hook Not tainted 6.16.0-rc5-next-20250711-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:473 [inline]
RIP: 0010:lock_is_held_type+0x10b/0x190 kernel/locking/lockdep.c:5944
Code: 0f 95 c0 31 db 39 c5 0f 94 c3 eb 05 bb 01 00 00 00 48 c7 c7 4c 03 e8 8d e8 92 16 00 00 b8 ff ff ff ff 65 0f c1 05 85 e7 67 07 <83> f8 01 75 44 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02
RSP: 0000:ffffc90003af7938 EFLAGS: 00000057
RAX: 0000000000000001 RBX: 0000000000000000 RCX: c7b1fa83a02e0b00
RDX: ffff88804fb9bc00 RSI: ffffffff8de8034c RDI: ffffffff8c04d240
RBP: 00000000ffffffff R08: ffffea00003859c7 R09: 1ffffd4000070b38
R10: dffffc0000000000 R11: fffff94000070b39 R12: 0000000000000246
R13: ffff88804fb9bc00 R14: ffff88803392ab18 R15: 0000000000000005
FS: 00007f34c3c69c80(0000) GS:ffff88812578f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f34c3dc22a0 CR3: 000000006a428000 CR4: 00000000003526f0
DR0: 0000000000000004 DR1: 0000000000000cb8 DR2: 0000000000000000
DR3: 0000000000000003 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
lock_is_held include/linux/lockdep.h:249 [inline]
xa_entry include/linux/xarray.h:1226 [inline]
xas_reload+0xfc/0x470 include/linux/xarray.h:1630
next_uptodate_folio+0x15f/0x5d0 mm/filemap.c:3610
filemap_map_pages+0x102b/0x1740 mm/filemap.c:3789
do_fault_around mm/memory.c:5544 [inline]
do_read_fault mm/memory.c:5577 [inline]
do_fault mm/memory.c:5720 [inline]
do_pte_missing mm/memory.c:4247 [inline]
handle_pte_fault mm/memory.c:6065 [inline]
__handle_mm_fault+0x34a9/0x5440 mm/memory.c:6208
handle_mm_fault+0x40a/0x8e0 mm/memory.c:6377
do_user_addr_fault+0xa81/0x1390 arch/x86/mm/fault.c:1336
handle_page_fault arch/x86/mm/fault.c:1476 [inline]
exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x7f34c3dc22a0
Code: 40 00 85 c9 74 04 a8 01 75 d0 b8 10 00 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 c7 47 08 01 00 00 00 eb cd 0f 1f 80 00 00 00 00 <55> 49 89 f8 53 48 83 ec 08 8b 57 18 64 8b 04 25 d0 02 00 00 39 c2
RSP: 002b:00007ffd817d7158 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00007ffd817d7178 RCX: 00007f34c3e03670
RDX: 0000000000000000 RSI: 0000000000000018 RDI: 00007f34c3f04b60
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 00007f34c3c69f50 R11: 0000000000000246 R12: 000055679a1e5f70
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000