INFO: task syz.1.970:9772 blocked for more than 143 seconds.
Not tainted 6.14.0-rc3-next-20250218-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.970 state:D stack:25504 pid:9772 tgid:9769 ppid:5842 task_flags:0x400040 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5373 [inline]
__schedule+0x190e/0x4c90 kernel/sched/core.c:6760
__schedule_loop kernel/sched/core.c:6837 [inline]
schedule+0x14b/0x320 kernel/sched/core.c:6852
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6909
__mutex_lock_common kernel/locking/mutex.c:662 [inline]
__mutex_lock+0x817/0x1010 kernel/locking/mutex.c:730
sync_bdevs+0x1ae/0x340 block/bdev.c:1246
ksys_sync+0xe2/0x1c0 fs/sync.c:105
__do_sys_sync+0xe/0x20 fs/sync.c:113
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fae2d38d169
RSP: 002b:00007fae2e28e038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fae2d5a6080 RCX: 00007fae2d38d169
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fae2d5a6080 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fae2d5a6080 R15: 00007ffc3bbd1f88
Showing all locks held in the system:
1 lock held by khungtaskd/30:
#0: ffffffff8eb3b3a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8eb3b3a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8eb3b3a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746
3 locks held by kworker/u8:2/35:
3 locks held by kworker/u8:7/1163:
#0: ffff88801b089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801b089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319
#1: ffffc90003eefc60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc90003eefc60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319
#2: ffffffff8fee0408 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:285
5 locks held by kworker/u8:9/3028:
#0: ffff88801bef5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801bef5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319
#1: ffffc9000be87c60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc9000be87c60 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319
#2: ffffffff8fed3c90 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x17a/0xd60 net/core/net_namespace.c:606
#3: ffffffff8fee0408 (rtnl_mutex){+.+.}-{4:4}, at: cleanup_net+0x6bf/0xd60 net/core/net_namespace.c:642
#4: ffffffff8eb408b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline]
#4: ffffffff8eb408b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x820 kernel/rcu/tree_exp.h:998
2 locks held by getty/5585:
#0: ffff8880361a20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000331b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x616/0x1770 drivers/tty/n_tty.c:2211
3 locks held by kworker/0:3/5847:
#0: ffff88801b080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801b080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319
#1: ffffc90004e3fc60 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc90004e3fc60 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319
#2: ffffffff8eb408b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline]
#2: ffffffff8eb408b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x820 kernel/rcu/tree_exp.h:998
3 locks held by kworker/1:4/5887:
#0: ffff88801b080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801b080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319
#1: ffffc900041efc60 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc900041efc60 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319
#2: ffffffff8fee0408 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
1 lock held by udevd/5981:
#0: ffff888025e3c4c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xf0/0xc50 block/bdev.c:903
3 locks held by kworker/u8:14/7749:
#0: ffff88814d259148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88814d259148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319
#1: ffffc9000bdd7c60 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc9000bdd7c60 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319
#2: ffffffff8fee0408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8fee0408 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x10e/0x16a0 net/ipv6/addrconf.c:4190
1 lock held by syz.1.970/9772:
#0: ffff888025e3c4c8 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ae/0x340 block/bdev.c:1246
3 locks held by syz-executor/9905:
#0: ffff88805c440d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:480 [inline]
#0: ffff88805c440d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x203/0x510 net/bluetooth/hci_core.c:2677
#1: ffff88805c440078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x60d/0x1260 net/bluetooth/hci_sync.c:5185
#2: ffff88805e26b338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x71/0x690 net/bluetooth/l2cap_core.c:1760
1 lock held by syz-executor/10904:
#0: ffffffff8fee0408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
#0: ffffffff8fee0408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:340 [inline]
#0: ffffffff8fee0408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc55/0x1d30 net/core/rtnetlink.c:4026
2 locks held by syz-executor/11306:
#0: ffffffff8fed3c90 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:512
#1: ffffffff8fee0408 (rtnl_mutex){+.+.}-{4:4}, at: wg_netns_pre_exit+0x1f/0x1e0 drivers/net/wireguard/device.c:415
3 locks held by syz.7.1327/11334:
#0: ffff888060a84d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:480 [inline]
#0: ffff888060a84d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x203/0x510 net/bluetooth/hci_core.c:2677
#1: ffff888060a84078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x60d/0x1260 net/bluetooth/hci_sync.c:5185
#2: ffff888021f87338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x71/0x690 net/bluetooth/l2cap_core.c:1760
1 lock held by syz.5.1329/11339:
#0: ffffffff8fee0408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
#0: ffffffff8fee0408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8fee0408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink+0x394/0x8d0 net/core/rtnetlink.c:3525
1 lock held by syz.5.1329/11342:
#0: ffffffff8fee0408 (rtnl_mutex){+.+.}-{4:4}, at: xsk_bind+0x151/0xfe0 net/xdp/xsk.c:1168
2 locks held by dhcpcd-run-hook/11378:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.14.0-rc3-next-20250218-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline]
watchdog+0x1058/0x10a0 kernel/hung_task.c:399
kthread+0x7a9/0x920 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 55 Comm: kworker/u9:0 Not tainted 6.14.0-rc3-next-20250218-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: hci1 hci_cmd_timeout
RIP: 0010:io_serial_in+0x76/0xb0 drivers/tty/serial/8250/8250_port.c:409
Code: 30 e7 3a fc 89 e9 41 d3 e6 48 83 c3 40 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 b1 68 a2 fc 44 03 33 44 89 f2 ec <0f> b6 c0 5b 41 5e 41 5f 5d c3 cc cc cc cc 89 e9 80 e1 07 38 c1 7c
RSP: 0018:ffffc9000120f298 EFLAGS: 00000002
RAX: 1ffffffff3536f00 RBX: ffffffff9a9b7ce0 RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020
RBP: 0000000000000000 R08: ffffffff858717a6 R09: 1ffff11004a89046
R10: dffffc0000000000 R11: ffffffff85871760 R12: 0000000000000020
R13: 1ffffffff3536fee R14: 00000000000003fd R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3b6bfef772 CR3: 0000000057846000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:137 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:159 [inline]
wait_for_lsr+0x1b1/0x320 drivers/tty/serial/8250/8250_port.c:2100
fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3357 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3380 [inline]
serial8250_console_write+0x134c/0x1e00 drivers/tty/serial/8250/8250_port.c:3465
console_emit_next_record kernel/printk/printk.c:3122 [inline]
console_flush_all+0x869/0xeb0 kernel/printk/printk.c:3210
__console_flush_and_unlock kernel/printk/printk.c:3269 [inline]
console_unlock+0x14f/0x3b0 kernel/printk/printk.c:3309
vprintk_emit+0x730/0xa10 kernel/printk/printk.c:2432
_printk+0xd5/0x120 kernel/printk/printk.c:2457
bt_err+0x127/0x180 net/bluetooth/lib.c:296
hci_cmd_timeout+0x104/0x1e0 net/bluetooth/hci_core.c:1456
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3319
worker_thread+0x870/0xd30 kernel/workqueue.c:3400
kthread+0x7a9/0x920 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245