INFO: task kworker/1:1H:1707 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:1H state:D stack:27144 pid:1707 tgid:1707 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: kblockd blk_mq_run_work_fn
Call Trace:
context_switch kernel/sched/core.c:5526 [inline]
__schedule+0x17db/0x58f0 kernel/sched/core.c:7276
__schedule_loop kernel/sched/core.c:7353 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7368
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
wait_for_reconnect drivers/block/nbd.c:1107 [inline]
nbd_handle_cmd drivers/block/nbd.c:1149 [inline]
nbd_queue_rq+0x96f/0xff0 drivers/block/nbd.c:1207
blk_mq_dispatch_rq_list+0x499/0x1990 block/blk-mq.c:2117
__blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
__blk_mq_sched_dispatch_requests+0xd36/0x1580 block/blk-mq-sched.c:307
blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329
blk_mq_run_work_fn+0x16c/0x300 block/blk-mq.c:2532
process_one_work kernel/workqueue.c:3396 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Showing all locks held in the system:
locks held by khungtaskd/32: 1, last CPU#1:
#0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by kworker/1:1H/1707: 4, on CPU#1:
#0: ffff88801eaf8940 ((wq_completion)kblockd){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff88801eaf8940 ((wq_completion)kblockd){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff88801eaf8940 ((wq_completion)kblockd){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#0: ffff88801eaf8940 ((wq_completion)kblockd){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#1: ffffc90006577c40 ((work_completion)(&(&hctx->run_work)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90006577c40 ((work_completion)(&(&hctx->run_work)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90006577c40 ((work_completion)(&(&hctx->run_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#1: ffffc90006577c40 ((work_completion)(&(&hctx->run_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#2: ffff888027241e98 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:198 [inline]
#2: ffff888027241e98 (set->srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:305 [inline]
#2: ffff888027241e98 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_work_fn+0x144/0x300 block/blk-mq.c:2531
#3: ffff8880552851f8 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xc1/0xff0 drivers/block/nbd.c:1199
locks held by dhcpcd/5280: 2, on CPU#0:
#0: ffffffff902c34a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff902c32e0 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline]
#1: ffffffff902c32e0 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline]
#1: ffffffff902c32e0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208
locks held by getty/5374: 2, on CPU#1:
#0: ffff888034b630a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by udevd/5627: 1, on CPU#1:
#0: ffff888027abf350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:990
locks held by syz-executor/15260: 2, on CPU#1:
#0: ffffffff902c34a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff902c32e0 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline]
#1: ffffffff902c32e0 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline]
#1: ffffffff902c32e0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208
locks held by syz.4.2849/15626: 1, on CPU#1:
#0: ffff888052084140 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#0: ffff888052084140 (&dev->mutex){....}-{4:4}, at: nfc_unregister_rfkill+0x63/0x280 net/nfc/core.c:1166
locks held by syz.4.2849/15627: 4, on CPU#1:
#0: ffffffff902c34a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff902c32e0 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline]
#1: ffffffff902c32e0 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline]
#1: ffffffff902c32e0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208
#2: ffff888052084140 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#2: ffff888052084140 (&dev->mutex){....}-{4:4}, at: nfc_dev_up+0x3c/0x350 net/nfc/core.c:95
#3: ffff88807c20e348 (&ndev->req_lock){+.+.}-{4:4}, at: nci_open_device net/nfc/nci/core.c:478 [inline]
#3: ffff88807c20e348 (&ndev->req_lock){+.+.}-{4:4}, at: nci_dev_up+0xa3/0xdc0 net/nfc/nci/core.c:643
locks held by syz.4.2849/15635: 2, on CPU#0:
#0: ffffffff902c34a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff902c32e0 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline]
#1: ffffffff902c32e0 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline]
#1: ffffffff902c32e0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208
locks held by syz.3.2854/15648: 2, on CPU#0:
#0: ffffffff902c34a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff902c32e0 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline]
#1: ffffffff902c32e0 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline]
#1: ffffffff902c32e0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208
locks held by syz.2.2856/15665: 2, on CPU#0:
#0: ffffffff902c34a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff902c32e0 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline]
#1: ffffffff902c32e0 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline]
#1: ffffffff902c32e0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208
locks held by syz.0.2859/15674: 2, on CPU#1:
#0: ffffffff902c34a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff902c32e0 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline]
#1: ffffffff902c32e0 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline]
#1: ffffffff902c32e0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 32 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123
nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66
trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xfd7/0x1030 kernel/hung_task.c:561
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
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: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64
Code: 4c 8f 02 c3 cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 33 41 24 00 fb f4 8c 08 03 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffffff8ea07ca0 EFLAGS: 00000242
RAX: 000000000012afe3 RBX: ffffffff819baed0 RCX: 8000000000000001
RDX: 0000000000000001 RSI: ffffffff8e4777d4 RDI: ffffffff8c6d9c80
RBP: ffffffff8ea07d78 R08: ffff8880b8633a1b R09: 1ffff110170c6743
R10: dffffc0000000000 R11: ffffed10170c6744 R12: 0000000000000000
R13: 1ffffffff1d51df8 R14: 1ffffffff1d40f9c R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888124cd1000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb6b79eb840 CR3: 00000000332de000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/kernel/process.c:767 [inline]
default_idle+0x9/0x20 arch/x86/kernel/process.c:768
default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:199 [inline]
do_idle+0x2e0/0x540 kernel/sched/idle.c:355
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:454
rest_init+0x378/0x3a0 init/main.c:727
start_kernel+0x392/0x3e0 init/main.c:1185
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x137/0x1b0 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x157