INFO: task syz.0.21:5951 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.21 state:D stack:27912 pid:5951 ppid:5762 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747
blkdev_get_by_dev+0x121/0x600 block/bdev.c:805
blkdev_open+0x152/0x360 block/fops.c:589
do_dentry_open+0x8c6/0x1500 fs/open.c:929
do_open fs/namei.c:3640 [inline]
path_openat+0x274b/0x3190 fs/namei.c:3797
do_filp_open+0x1c5/0x3d0 fs/namei.c:3824
do_sys_openat2+0x12c/0x1c0 fs/open.c:1421
do_sys_open fs/open.c:1436 [inline]
__do_sys_openat fs/open.c:1452 [inline]
__se_sys_openat fs/open.c:1447 [inline]
__x64_sys_openat+0x139/0x160 fs/open.c:1447
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f214878df90
RSP: 002b:00007f2149673b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00000000000e2000 RCX: 00007f214878df90
RDX: 00000000000e2000 RSI: 00007f2149673c10 RDI: 00000000ffffff9c
RBP: 00007f2149673c10 R08: 0000000000000000 R09: 002364626e2f7665
R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd
R13: 00007f21489e6038 R14: 00007f21489e5fa0 R15: 00007ffe08f961c8
Showing all locks held in the system:
2 locks held by kworker/u4:0/11:
1 lock held by khungtaskd/29:
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by getty/5523:
#0: ffff888030cb20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
1 lock held by udevd/5754:
#0: ffff8881413074c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805
2 locks held by kworker/1:4/5826:
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc90004a0fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90004a0fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
3 locks held by kworker/1:5/5848:
7 locks held by kworker/1:6/5919:
1 lock held by syz.0.21/5951:
#0: ffff8881413074c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805
2 locks held by syz.5.428/7846:
#0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
#0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6469
#1: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline]
#1: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x448/0x830 kernel/rcu/tree_exp.h:1004
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf41/0xf80 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5848 Comm: kworker/1:5 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: usb_hub_wq hub_event
RIP: 0010:do_slab_free mm/slub.c:3777 [inline]
RIP: 0010:___cache_free+0x6e/0x140 mm/slub.c:3837
Code: 48 08 f6 c1 01 0f 85 aa 00 00 00 66 90 4c 8b 00 49 c1 e0 34 49 c1 f8 3f 49 21 c0 49 8b 07 65 48 03 05 8e ee 25 7e 48 8b 78 08 <4c> 3b 40 10 75 31 4c 8b 08 41 8b 47 28 4c 89 0c 18 48 8d 4f 08 4d
RSP: 0018:ffffc90004a5f230 EFLAGS: 00000286
RAX: ffff8880b8f44200 RBX: ffff8880688d7740 RCX: ffff888142e73280
RDX: ffffea0000000000 RSI: 00000000000fffff RDI: 0000000000063799
RBP: ffff888050d8d000 R08: ffffea0001a23500 R09: 1ffff110171e83d8
R10: dffffc0000000000 R11: ffffed10171e83d9 R12: ffff888142e73280
R13: dffffc0000000000 R14: ffffffff81dd0dba R15: ffff888142e73280
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa4435b7198 CR3: 000000000cb30000 CR4: 00000000003506e0
Call Trace:
qlink_free mm/kasan/quarantine.c:166 [inline]
qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185
kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305
kasan_slab_alloc include/linux/kasan.h:188 [inline]
slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767
slab_alloc_node mm/slub.c:3495 [inline]
slab_alloc mm/slub.c:3503 [inline]
__kmem_cache_alloc_lru mm/slub.c:3510 [inline]
kmem_cache_alloc+0x11e/0x2e0 mm/slub.c:3519
kmem_cache_zalloc include/linux/slab.h:711 [inline]
__kernfs_new_node+0xd8/0x7e0 fs/kernfs/dir.c:624
kernfs_new_node+0x14c/0x260 fs/kernfs/dir.c:700
__kernfs_create_file+0x4b/0x2e0 fs/kernfs/file.c:1068
sysfs_add_bin_file_mode_ns fs/sysfs/file.c:329 [inline]
sysfs_create_bin_file+0x2c9/0x3b0 fs/sysfs/file.c:570
usb_create_sysfs_dev_files+0x30/0x400 drivers/usb/core/sysfs.c:1019
usb_bus_notify+0xda/0x110 drivers/usb/core/usb.c:1044
notifier_call_chain+0x197/0x390 kernel/notifier.c:93
blocking_notifier_call_chain+0x6a/0x90 kernel/notifier.c:388
bus_notify+0x13e/0x180 drivers/base/bus.c:998
device_add+0x5de/0xc20 drivers/base/core.c:3663
usb_new_device+0xa31/0x1630 drivers/usb/core/hub.c:2660
hub_port_connect drivers/usb/core/hub.c:5529 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5669 [inline]
port_event drivers/usb/core/hub.c:5833 [inline]
hub_event+0x2962/0x49c0 drivers/usb/core/hub.c:5915
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293