vhci_hcd: disconnect device vhci_hcd: stop threads vhci_hcd: release socket vhci_hcd: connection closed vhci_hcd: disconnect device BUG: unable to handle kernel NULL pointer dereference at 000000000000001c IP: atomic_inc arch/x86/include/asm/atomic.h:92 [inline] IP: kthread_stop+0x47/0x640 kernel/kthread.c:525 PGD 9b244067 P4D 9b244067 PUD 9bba4067 PMD 0 Oops: 0002 [#1] PREEMPT SMP KASAN Modules linked in: CPU: 1 PID: 8666 Comm: kworker/u4:2 Not tainted 4.14.212-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: usbip_event event_handler task: ffff8880aadb62c0 task.stack: ffff88809f1a8000 RIP: 0010:atomic_inc arch/x86/include/asm/atomic.h:92 [inline] RIP: 0010:kthread_stop+0x47/0x640 kernel/kthread.c:525 RSP: 0018:ffff88809f1afc70 EFLAGS: 00010297 RAX: ffff8880aadb62c0 RBX: 0000000000000001 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 00000000ffffffff RDI: 0000000000000286 RBP: fffffffffffffffc R08: ffffffff8b9b0148 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff888237d1c918 R13: ffff888237d1c908 R14: fffffbfff1924130 R15: ffffffff89857f80 FS: 0000000000000000(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 vhci_hcd vhci_hcd.0: pdev(2) rhport(1) sockfd(3) CR2: 000000000000001c CR3: 000000009b0f3000 CR4: 00000000001406e0 vhci_hcd vhci_hcd.0: devid(0) speed(5) speed_str(super-speed) 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: connection closed event_handler+0x1c3/0x4a0 drivers/usb/usbip/usbip_event.c:92 vhci_hcd vhci_hcd.0: pdev(3) rhport(1) sockfd(3) process_one_work+0x793/0x14a0 kernel/workqueue.c:2116 vhci_hcd vhci_hcd.0: devid(0) speed(5) speed_str(super-speed) worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250 vhci_hcd: connection closed kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Code: vhci_hcd vhci_hcd.0: pdev(3) rhport(0) sockfd(3) 00 vhci_hcd vhci_hcd.0: devid(0) speed(5) speed_str(super-speed) 65 8b 1d bc 17 c9 7e 83 fb 07 0f 87 5b 04 00 00 e8 be d5 1e 00 89 db 48 0f a3 1d 0c 44 d0 08 0f 82 a2 03 00 00 e8 a9 d5 1e 00 ff 45 20 48 8d 7d 24 48 b8 00 00 00 00 00 fc ff df 48 89 fa vhci_hcd: connection closed RIP: atomic_inc arch/x86/include/asm/atomic.h:92 [inline] RSP: ffff88809f1afc70 RIP: kthread_stop+0x47/0x640 kernel/kthread.c:525 RSP: ffff88809f1afc70 CR2: 000000000000001c ---[ end trace 847be8955c6a31c8 ]---