INFO: task syz.1.7130:30509 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.1.7130 state:D stack:26888 pid:30509 tgid:30508 ppid:28530 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0x164/0x360 kernel/sched/core.c:7282 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7339 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7f7/0x1550 kernel/locking/mutex.c:820 device_lock include/linux/device.h:1040 [inline] usbdev_open+0x182/0x770 drivers/usb/core/devio.c:1054 chrdev_open+0x4cd/0x5e0 fs/char_dev.c:411 do_dentry_open+0x785/0x14e0 fs/open.c:947 vfs_open+0x3b/0x340 fs/open.c:1079 do_open fs/namei.c:4699 [inline] path_openat+0x2e08/0x3860 fs/namei.c:4858 do_file_open+0x23e/0x4a0 fs/namei.c:4887 do_sys_openat2+0x113/0x200 fs/open.c:1364 do_sys_open fs/open.c:1370 [inline] __do_sys_openat fs/open.c:1386 [inline] __se_sys_openat fs/open.c:1381 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1381 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2315d5d60e RSP: 002b:00007f2316d43b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f2316d446c0 RCX: 00007f2315d5d60e RDX: 0000000000002002 RSI: 00007f2316d43c00 RDI: ffffffffffffff9c RBP: 00007f2316d43c00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd R13: 00007f2316016038 R14: 00007f2316015fa0 R15: 00007f231613fa48 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/1:1/50: #0: ffff88813fe43140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff88813fe43140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc90000ba7c40 ((work_completion)(&m->mpeg_thread)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc90000ba7c40 ((work_completion)(&m->mpeg_thread)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 2 locks held by getty/5378: #0: ffff8880364410a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211 6 locks held by kworker/1:7/5711: 1 lock held by syz.1.7130/30509: #0: ffff88802a1c41d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #0: ffff88802a1c41d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x182/0x770 drivers/usb/core/devio.c:1054 1 lock held by syz.7.7756/32685: 2 locks held by dhcpcd/32689: #0: ffff888052b42260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] #0: ffff888052b42260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xe10 net/packet/af_packet.c:3204 #1: ffffffff8e963068 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #1: ffffffff8e963068 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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:162 [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+0xfd3/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5711 Comm: kworker/1:7 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: usb_hub_wq hub_event RIP: 0010:unwind_next_frame+0x172/0x2550 arch/x86/kernel/unwind_orc.c:510 Code: d8 48 c1 e8 03 0f b6 04 28 84 c0 0f 85 a5 1c 00 00 f6 03 03 0f 85 ef 19 00 00 49 8d 5e 35 48 89 d8 48 c1 e8 03 48 89 44 24 38 <0f> b6 04 28 84 c0 0f 85 9c 1c 00 00 4c 89 6c 24 20 4c 89 7c 24 50 RSP: 0018:ffffc90004be6598 EFLAGS: 00000a03 RAX: 1ffff9200097ccd3 RBX: ffffc90004be669d RCX: 0000000080000001 RDX: 00000000fe47ebb6 RSI: ffffffff8c28ab40 RDI: ffffffff8c28ab00 RBP: dffffc0000000000 R08: ffffffff8176e256 R09: ffffffff8e95cd60 R10: ffffc90004be66b8 R11: ffffffff81b0d880 R12: ffffc90004be66a0 R13: 1ffff9200097cccd R14: ffffc90004be6668 R15: ffffffff8176e256 FS: 0000000000000000(0000) GS:ffff888125393000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c407e19 CR3: 000000007467a000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000001800 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5295 [inline] __kmalloc_node_track_caller_noprof+0x4db/0x7b0 mm/slub.c:5403 kmalloc_reserve net/core/skbuff.c:635 [inline] __alloc_skb+0x2c1/0x7d0 net/core/skbuff.c:713 __netdev_alloc_skb+0xc1/0x810 net/core/skbuff.c:775 netdev_alloc_skb include/linux/skbuff.h:3499 [inline] dev_alloc_skb include/linux/skbuff.h:3512 [inline] ath6kl_usb_post_recv_transfers+0x207/0x6f0 drivers/net/wireless/ath/ath6kl/usb.c:427 ath6kl_usb_start_recv_pipes drivers/net/wireless/ath/ath6kl/usb.c:497 [inline] hif_start drivers/net/wireless/ath/ath6kl/usb.c:702 [inline] ath6kl_usb_power_on+0x6a/0x280 drivers/net/wireless/ath/ath6kl/usb.c:1061 ath6kl_hif_power_on drivers/net/wireless/ath/ath6kl/hif-ops.h:136 [inline] ath6kl_core_init+0x1e1/0x10b0 drivers/net/wireless/ath/ath6kl/core.c:97 ath6kl_usb_probe+0x14a6/0x15a0 drivers/net/wireless/ath/ath6kl/usb.c:1162 usb_probe_interface+0x659/0xc70 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x267/0xaf0 drivers/base/dd.c:709 __driver_probe_device+0x1ef/0x380 drivers/base/dd.c:871 driver_probe_device+0x4f/0x240 drivers/base/dd.c:901 __device_attach_driver+0x279/0x430 drivers/base/dd.c:1029 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500 __device_attach+0x2c5/0x450 drivers/base/dd.c:1101 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1156 bus_probe_device+0x12a/0x220 drivers/base/bus.c:613 device_add+0x7e9/0xbb0 drivers/base/core.c:3706 usb_set_configuration+0x1a87/0x2110 drivers/usb/core/message.c:2268 usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250 usb_probe_device+0x1c4/0x3b0 drivers/usb/core/driver.c:291 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x267/0xaf0 drivers/base/dd.c:709 __driver_probe_device+0x1ef/0x380 drivers/base/dd.c:871 driver_probe_device+0x4f/0x240 drivers/base/dd.c:901 __device_attach_driver+0x279/0x430 drivers/base/dd.c:1029 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500 __device_attach+0x2c5/0x450 drivers/base/dd.c:1101 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1156 bus_probe_device+0x12a/0x220 drivers/base/bus.c:613 device_add+0x7e9/0xbb0 drivers/base/core.c:3706 usb_new_device+0xa08/0x16f0 drivers/usb/core/hub.c:2695 hub_port_connect drivers/usb/core/hub.c:5567 [inline] hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] port_event drivers/usb/core/hub.c:5871 [inline] hub_event+0x2a1c/0x4f30 drivers/usb/core/hub.c:5953 process_one_work kernel/workqueue.c:3302 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466 kthread+0x388/0x470 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