INFO: task syz.4.7945:23103 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.4.7945 state:D stack:26728 pid:23103 tgid:23102 ppid:5804 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0x147b/0x4f50 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7245
rt_mutex_slowlock_block+0x508/0x680 kernel/locking/rtmutex.c:1647
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline]
rt_mutex_slowlock+0x2dc/0x710 kernel/locking/rtmutex.c:1800
__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
__mutex_lock_common kernel/locking/rtmutex_api.c:534 [inline]
mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:552
device_lock include/linux/device.h:895 [inline]
usbdev_open+0x182/0x790 drivers/usb/core/devio.c:1054
chrdev_open+0x4d0/0x5f0 fs/char_dev.c:414
do_dentry_open+0x7d0/0x1270 fs/open.c:962
vfs_open+0x3b/0x350 fs/open.c:1094
do_open fs/namei.c:4637 [inline]
path_openat+0x34c9/0x3e70 fs/namei.c:4796
do_filp_open+0x22d/0x490 fs/namei.c:4823
do_sys_openat2+0x12f/0x220 fs/open.c:1430
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+0x138/0x170 fs/open.c:1447
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f35610cb58e
RSP: 002b:00007f355f365b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f355f3666c0 RCX: 00007f35610cb58e
RDX: 0000000000000002 RSI: 00007f355f365c00 RDI: ffffffffffffff9c
RBP: 00007f355f365c00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007f3561386038 R14: 00007f3561385fa0 R15: 00007fff9015fe98
Showing all locks held in the system:
1 lock held by rcu_tasks_trace/36:
#0: ffffffff8d9c84a0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{4:4}, at: rcu_tasks_one_gp+0xaf4/0xde0 kernel/rcu/tasks.h:614
1 lock held by khungtaskd/38:
#0: ffffffff8d9c7780 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d9c7780 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8d9c7780 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:6/1023:
2 locks held by getty/5562:
#0: ffff8880315d50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211
10 locks held by syz-executor/5803:
6 locks held by kworker/0:6/5930:
9 locks held by syz-executor/17575:
1 lock held by syz.4.7945/23103:
#0: ffff8880280d9188 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#0: ffff8880280d9188 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x182/0x790 drivers/usb/core/devio.c:1054
4 locks held by syz-executor/23431:
6 locks held by syz-executor/26639:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 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+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xf90/0xfe0 kernel/hung_task.c:515
kthread+0x726/0x8b0 kernel/kthread.c:463
ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 26640 Comm: syz.2.9547 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
RIP: 0010:filter_irq_stacks+0x32/0xa0 kernel/stacktrace.c:397
Code: 41 55 41 54 53 85 f6 74 70 49 89 fe 41 89 f4 31 db 49 bd 00 00 00 00 00 fc ff df 49 89 ff 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 <74> 08 4c 89 ff e8 44 56 77 00 49 8b 04 de 48 3d 30 02 00 81 0f 93
RSP: 0018:ffffc9000621f978 EFLAGS: 00000246
RAX: 1ffff92000c43f45 RBX: 0000000000000005 RCX: 0000000000000001
RDX: 0000000000000d00 RSI: 000000000000000c RDI: ffffc9000621fa00
RBP: ffffc9000621fc28 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc9000621f918 R11: ffffffff81ad1370 R12: 000000000000000c
R13: dffffc0000000000 R14: ffffc9000621fa00 R15: ffffc9000621fa28
FS: 00007fa3e18d66c0(0000) GS:ffff8881268fc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa3e18d5ff8 CR3: 000000007eaba000 CR4: 00000000003526f0
Call Trace:
stack_depot_save_flags+0x33/0x810 lib/stackdepot.c:659
kasan_save_stack mm/kasan/common.c:58 [inline]
kasan_save_track+0x4f/0x80 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5263 [inline]
kmem_cache_alloc_noprof+0x188/0x6a0 mm/slub.c:5270
lsm_file_alloc security/security.c:169 [inline]
security_file_alloc+0x34/0x310 security/security.c:2380
init_file+0x99/0x310 fs/file_table.c:159
alloc_empty_file+0x6e/0x1d0 fs/file_table.c:241
alloc_file fs/file_table.c:354 [inline]
alloc_file_pseudo+0x155/0x240 fs/file_table.c:383
sock_alloc_file+0xb8/0x2f0 net/socket.c:483
sock_map_fd net/socket.c:513 [inline]
__sys_socket+0x13c/0x1b0 net/socket.c:1756
__do_sys_socket net/socket.c:1761 [inline]
__se_sys_socket net/socket.c:1759 [inline]
__x64_sys_socket+0x7a/0x90 net/socket.c:1759
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa3e367acb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa3e18d6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000029
RAX: ffffffffffffffda RBX: 00007fa3e38f5fa0 RCX: 00007fa3e367acb9
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 000000000000000a
RBP: 00007fa3e36e8bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa3e38f6038 R14: 00007fa3e38f5fa0 R15: 00007ffc45e40d78