INFO: task syz.6.2640:16869 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.2640 state:D stack:26904 pid:16869 tgid:16868 ppid:14803 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0xfee/0x60e0 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7004
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
sync_bdevs+0x153/0x480 block/bdev.c:1304
ksys_sync+0xb0/0xf0 fs/sync.c:105
__do_sys_sync+0xe/0x20 fs/sync.c:111
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f152779c629
RSP: 002b:00007f15285e3028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f1527a15fa0 RCX: 00007f152779c629
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f1527a15fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1527a16038 R14: 00007f1527a15fa0 R15: 00007ffc95fa7078
Showing all locks held in the system:
3 locks held by kworker/u8:1/13:
1 lock held by khungtaskd/31:
#0: ffffffff8e7e93e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e7e93e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e7e93e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:10/3652:
2 locks held by dhcpcd/5474:
2 locks held by getty/5562:
#0: ffff8880342290a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211
6 locks held by kworker/1:4/5866:
#0: ffff888020ec8948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1287/0x1920 kernel/workqueue.c:3250
#1: ffffc9000466fd08 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x93c/0x1920 kernel/workqueue.c:3251
#2: ffff88802b794198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#2: ffff88802b794198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
#3: ffff88802bc03198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#3: ffff88802bc03198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1008
#4: ffff88802bba5160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#4: ffff88802bba5160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1008
#5: ffff88801cac8188 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_add_one+0x38/0x850 fs/kernfs/dir.c:796
5 locks held by kworker/1:8/7710:
#0: ffff888020ec8948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1287/0x1920 kernel/workqueue.c:3250
#1: ffffc9000c5cfd08 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x93c/0x1920 kernel/workqueue.c:3251
#2: ffff88802b5fa198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#2: ffff88802b5fa198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
#3: ffff88802bc07198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#3: ffff88802bc07198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1008
#4: ffff88802bba2160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#4: ffff88802bba2160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1008
2 locks held by kworker/u8:11/11802:
1 lock held by udevd/12261:
#0: ffff8880281b6358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:961
4 locks held by udevd/14110:
#0: ffff88807d5bf790 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183
#1: ffff88804fdb4c88 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172
#2: ffff888059b39788 (kn->active#24){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888059b39788 (kn->active#24){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173
#3: ffff88802bc07198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:900 [inline]
#3: ffff88802bc07198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
1 lock held by syz.6.2640/16869:
#0: ffff8880281b6358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x153/0x480 block/bdev.c:1304
4 locks held by syz-executor/17141:
1 lock held by syz.9.3156/19276:
#0: ffff88801cac8188 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_add_one+0x38/0x850 fs/kernfs/dir.c:796
1 lock held by syz.2.3158/19294:
1 lock held by syz.2.3158/19295:
3 locks held by syz.1.3159/19282:
#0: ffff888059e7b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: __tty_ldisc_lock drivers/tty/tty_ldisc.c:289 [inline]
#0: ffff888059e7b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:335 [inline]
#0: ffff888059e7b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:366 [inline]
#0: ffff888059e7b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_release+0x154/0x2f0 drivers/tty/tty_ldisc.c:780
#1: ffff888059e7f0a0 (&tty->ldisc_sem/1){+.+.}-{0:0}
, at: __tty_ldisc_lock_nested drivers/tty/tty_ldisc.c:295 [inline]
, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:337 [inline]
, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:366 [inline]
, at: tty_ldisc_release+0x182/0x2f0 drivers/tty/tty_ldisc.c:780
#2: ffffffff9060f328 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff9060f328 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x146/0x360 net/core/dev.c:2162
1 lock held by syz.8.3161/19287:
#0: ffffffff8e7f4ff8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xd25/0x1050 kernel/hung_task.c:515
kthread+0x370/0x450 kernel/kthread.c:467
ret_from_fork+0x754/0xd80 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 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: d8 82 02 c3 cc cc cc cc 0f 1f 00 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 43 0c 1c 00 fb f4 bc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffffff8e407e00 EFLAGS: 00000242
RAX: 00000000058d74d5 RBX: ffffffff8e4975c0 RCX: ffffffff8b8f7c75
RDX: 0000000000000000 RSI: ffffffff8de71e08 RDI: ffffffff8c1aefa0
RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1017086795
R10: ffff8880b8433cab R11: 0000000000000000 R12: fffffbfff1c92eb8
R13: 0000000000000000 R14: ffffffff90d96410 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888124348000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000146030 CR3: 000000007404f000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:73 [inline]
default_idle+0x9/0x10 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x35b/0x4b0 kernel/sched/idle.c:332
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430
rest_init+0x251/0x260 init/main.c:760
start_kernel+0x47f/0x480 init/main.c:1210
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x12b/0x130 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x148