vhci_hcd vhci_hcd.0: port 2 already used vhci_hcd vhci_hcd.0: port 1 already used vhci_hcd vhci_hcd.0: pdev(0) rhport(3) sockfd(5) vhci_hcd vhci_hcd.0: port 3 already used vhci_hcd vhci_hcd.0: devid(0) speed(1) speed_str(low-speed) BUG: unable to handle kernel NULL pointer dereference at 000000000000001c vhci_hcd vhci_hcd.0: port 0 already used IP: atomic_inc arch/x86/include/asm/atomic.h:92 [inline] IP: kthread_stop+0x47/0x640 kernel/kthread.c:525 PGD aa6df067 P4D aa6df067 PUD aa6d4067 PMD 0 Oops: 0002 [#1] PREEMPT SMP KASAN Modules linked in: CPU: 1 PID: 364 Comm: kworker/u4:3 Not tainted 4.14.202-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: usbip_event event_handler task: ffff8880b493e080 task.stack: ffff8880b4948000 RIP: 0010:atomic_inc arch/x86/include/asm/atomic.h:92 [inline] RIP: 0010:kthread_stop+0x47/0x640 kernel/kthread.c:525 RSP: 0018:ffff8880b494fc70 EFLAGS: 00010297 vhci_hcd vhci_hcd.0: port 2 already used RAX: ffff8880b493e080 RBX: 0000000000000001 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 00000000ffffffff RDI: 0000000000000282 RBP: fffffffffffffffc R08: ffffffff8ae0a060 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880a9c88e98 R13: ffff8880a9c88e88 R14: fffffbfff1923f40 R15: ffffffff89859260 FS: 0000000000000000(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000000001c CR3: 00000000ac0db000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: vhci_shutdown_connection+0x12a/0x240 drivers/usb/usbip/vhci_hcd.c:1035 vhci_hcd vhci_hcd.0: port 1 already used event_handler+0x1c3/0x4a0 drivers/usb/usbip/usbip_event.c:92 vhci_hcd vhci_hcd.0: port 2 already used process_one_work+0x793/0x14a0 kernel/workqueue.c:2116 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250 kthread+0x30d/0x420 kernel/kthread.c:232 vhci_hcd vhci_hcd.0: port 0 already used ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Code: 00 65 8b vhci_hcd vhci_hcd.0: port 1 already used 1d 2c 1a c9 7e 83 fb 07 0f 87 5b 04 00 00 e8 8e d5 1e 00 89 db 48 0f a3 1d 3c 55 d0 08 0f 82 a2 03 00 vhci_hcd vhci_hcd.0: port 3 already used 00 e8 79 d5 1e 00 ff 45 20 48 8d 7d 24 48 b8 00 00 00 00 00 fc ff df 48 89 fa RIP: atomic_inc arch/x86/include/asm/atomic.h:92 [inline] RSP: ffff8880b494fc70 RIP: kthread_stop+0x47/0x640 kernel/kthread.c:525 RSP: ffff8880b494fc70 CR2: 000000000000001c ---[ end trace 496bf0aa11fcfd44 ]---