INFO: task syz.3.17:3964 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.17 state:D stack:27672 pid:3964 tgid:3964 ppid:3515 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0xeb0/0x3e50 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] schedule+0xdd/0x390 kernel/sched/core.c:6964 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common+0x2e7/0x4c0 kernel/sched/completion.c:121 usb_start_wait_urb+0x147/0x4c0 drivers/usb/core/message.c:64 usb_bulk_msg+0x22b/0x580 drivers/usb/core/message.c:388 send_request_dev_dep_msg_in drivers/usb/class/usbtmc.c:1350 [inline] usbtmc_read+0x5f4/0x10b0 drivers/usb/class/usbtmc.c:1409 vfs_read+0x1e4/0xb30 fs/read_write.c:570 ksys_read+0x12a/0x250 fs/read_write.c:715 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xc9/0x570 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1600bbaeb9 RSP: 002b:00007ffdc6c8cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f1600e35fa0 RCX: 00007f1600bbaeb9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 00007f1600c28c1f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1600e35fac R14: 00007f1600e35fa0 R15: 00007f1600e35fa0 Showing all locks held in the system: 6 locks held by kworker/0:0/9: #0: ffff888100ed2548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232 #1: ffffc9000009fca8 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233 #2: ffff88810ab0a198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff88810ab0a198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899 #3: ffff88811f5b2198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #3: ffff88811f5b2198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1006 #4: ffff88811f5b4160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #4: ffff88811f5b4160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1006 #5: ffffffff8a0d7bb0 (minor_rwsem){++++}-{4:4}, at: usb_register_dev+0x11d/0x570 drivers/usb/core/file.c:134 3 locks held by kworker/1:0/23: #0: ffff888100071948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232 #1: ffffc9000018fca8 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233 #2: ffff88810abd2198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff88810abd2198 (&dev->mutex){....}-{4:4}, at: ath9k_hif_usb_firmware_fail drivers/net/wireless/ath/ath9k/hif_usb.c:1161 [inline] #2: ffff88810abd2198 (&dev->mutex){....}-{4:4}, at: ath9k_hif_usb_firmware_cb+0x3b2/0x530 drivers/net/wireless/ath/ath9k/hif_usb.c:1294 1 lock held by khungtaskd/30: #0: ffffffff894da3a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff894da3a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff894da3a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:1/32: #0: ffff888100089148 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232 #1: ffffc90000227ca8 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233 2 locks held by getty/2922: #0: ffff888112c110a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900000452f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211 3 locks held by kworker/0:2/2954: #0: ffff888100071948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232 #1: ffffc900018afca8 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233 #2: ffff88810ab0a198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff88810ab0a198 (&dev->mutex){....}-{4:4}, at: ath9k_hif_usb_firmware_fail drivers/net/wireless/ath/ath9k/hif_usb.c:1161 [inline] #2: ffff88810ab0a198 (&dev->mutex){....}-{4:4}, at: ath9k_hif_usb_firmware_cb+0x3b2/0x530 drivers/net/wireless/ath/ath9k/hif_usb.c:1294 1 lock held by syz.3.17/3964: #0: ffff88811bdfd4d8 (&data->io_mutex){+.+.}-{4:4}, at: usbtmc_read+0x154/0x10b0 drivers/usb/class/usbtmc.c:1395 6 locks held by kworker/0:3/3969: #0: ffff888100ed2548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232 #1: ffffc90003d07ca8 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233 #2: ffff88810abd2198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff88810abd2198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899 #3: ffff8881171f9198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #3: ffff8881171f9198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1006 #4: ffff8881056b3160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #4: ffff8881056b3160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1006 #5: ffffffff8a0d7bb0 (minor_rwsem){++++}-{4:4}, at: usb_register_dev+0x11d/0x570 drivers/usb/core/file.c:134 2 locks held by syz.4.18/4421: #0: ffffffff8a0d7bb0 (minor_rwsem){++++}-{4:4}, at: usb_open+0x23/0x220 drivers/usb/core/file.c:38 #1: ffff88811bdfd4d8 (&data->io_mutex){+.+.}-{4:4}, at: usbtmc_open+0x4c8/0x950 drivers/usb/class/usbtmc.c:189 1 lock held by syz.5.19/4876: #0: ffffffff8a0d7bb0 (minor_rwsem){++++}-{4:4}, at: usb_open+0x23/0x220 drivers/usb/core/file.c:38 1 lock held by syz.6.20/5331: #0: ffffffff8a0d7bb0 (minor_rwsem){++++}-{4:4}, at: usb_open+0x23/0x220 drivers/usb/core/file.c:38 6 locks held by kworker/0:4/5335: #0: ffff888100ed2548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232 #1: ffffc90007037ca8 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233 #2: ffff88810abea198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff88810abea198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899 #3: ffff8881202d2198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #3: ffff8881202d2198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1006 #4: ffff8881202d5160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #4: ffff8881202d5160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1006 #5: ffffffff8a0d7bb0 (minor_rwsem){++++}-{4:4}, at: usb_register_dev+0x11d/0x570 drivers/usb/core/file.c:134 3 locks held by kworker/1:3/5628: #0: ffff888100071948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232 #1: ffffc900061bfca8 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233 #2: ffff88810abea198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff88810abea198 (&dev->mutex){....}-{4:4}, at: ath9k_hif_usb_firmware_fail drivers/net/wireless/ath/ath9k/hif_usb.c:1161 [inline] #2: ffff88810abea198 (&dev->mutex){....}-{4:4}, at: ath9k_hif_usb_firmware_cb+0x3b2/0x530 drivers/net/wireless/ath/ath9k/hif_usb.c:1294 1 lock held by syz.7.21/5788: #0: ffffffff8a0d7bb0 (minor_rwsem){++++}-{4:4}, at: usb_open+0x23/0x220 drivers/usb/core/file.c:38 2 locks held by modprobe/5915: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 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+0xcc3/0xfe0 kernel/hung_task.c:515 kthread+0x3b3/0x730 kernel/kthread.c:463 ret_from_fork+0x6c3/0xa20 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 2841 Comm: syslogd Not tainted syzkaller #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 RIP: 0010:lock_acquire+0x5e/0x330 kernel/locking/lockdep.c:5872 Code: 05 7b 34 3d 0b 83 f8 07 0f 87 a4 02 00 00 48 0f a3 05 06 aa 3e 09 0f 82 6f 02 00 00 8b 35 9e b6 3e 09 85 f6 0f 85 8a 00 00 00 <48> 8b 44 24 30 65 48 2b 05 1d 34 3d 0b 0f 85 b8 02 00 00 48 83 c4 RSP: 0018:ffffc900018bf458 EFLAGS: 00000206 RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff88dcbbf7 RDI: ffffffff878e97a0 RBP: ffffffff894da3a0 R08: 0000000090c8a11d R09: 0000000000000007 R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f83ee12fc80(0000) GS:ffff88826896a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f67cb66a6b0 CR3: 0000000115ffc000 CR4: 00000000003506f0 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0xd1/0x1ea0 arch/x86/kernel/unwind_orc.c:495 __unwind_start+0x3d1/0x7f0 arch/x86/kernel/unwind_orc.c:773 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0x73/0xf0 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x43/0x70 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6670 [inline] kfree+0x1ad/0x630 mm/slub.c:6878 skb_kfree_head net/core/skbuff.c:1068 [inline] skb_free_head+0x119/0x220 net/core/skbuff.c:1080 skb_release_data+0x540/0x700 net/core/skbuff.c:1107 skb_release_all net/core/skbuff.c:1182 [inline] __kfree_skb net/core/skbuff.c:1196 [inline] consume_skb net/core/skbuff.c:1428 [inline] consume_skb+0xc4/0x110 net/core/skbuff.c:1422 __unix_dgram_recvmsg+0x754/0xc30 net/unix/af_unix.c:2658 unix_dgram_recvmsg+0xd0/0x110 net/unix/af_unix.c:2675 sock_recvmsg_nosec net/socket.c:1078 [inline] sock_recvmsg+0x1f9/0x250 net/socket.c:1100 sock_read_iter+0x2c6/0x3c0 net/socket.c:1170 new_sync_read fs/read_write.c:491 [inline] vfs_read+0x957/0xb30 fs/read_write.c:572 ksys_read+0x1f8/0x250 fs/read_write.c:715 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xc9/0x570 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f83ee27f407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007fff2bb34ab0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f83ee12fc80 RCX: 00007f83ee27f407 RDX: 00000000000000ff RSI: 0000556425738300 RDI: 0000000000000000 RBP: 00005564257382c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000556425738351 R13: 0000000000000000 R14: 0000556425738300 R15: 00005563ea114d98