bisecting fixing commit since cbfa1702aaf69b2311ea1b35e04f113c48368c67 building syzkaller on 1a3f94087169f62f9a5832828f62b4900e98b781 testing commit cbfa1702aaf69b2311ea1b35e04f113c48368c67 with gcc (GCC) 8.4.1 20210217 kernel signature: 48e47b5098698166f1f1752a88071bcfc245ac71b410c97a8b50a6b5bc75719b run #0: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #1: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #2: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #3: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #4: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #5: crashed: BUG: unable to handle kernel run #6: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #7: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #8: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #9: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #10: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #11: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #12: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #13: crashed: BUG: unable to handle kernel run #14: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #15: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #16: crashed: INFO: task hung in hub_port_init run #17: crashed: INFO: task hung in hub_port_init run #18: crashed: INFO: task hung in hub_port_init run #19: crashed: INFO: task hung in hub_port_init testing current HEAD 29c52025152bab4c557d8174da58f1a4c8e70438 testing commit 29c52025152bab4c557d8174da58f1a4c8e70438 with gcc (GCC) 8.4.1 20210217 kernel signature: cd2dac40224281e14f01188493124e0752657adb79fb24e9be3a84e8fc2bf425 run #0: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #1: crashed: BUG: unable to handle kernel run #2: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #3: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #4: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #5: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #6: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #7: crashed: INFO: task hung in hub_port_init run #8: crashed: INFO: task hung in hub_port_init run #9: crashed: INFO: task hung in hub_port_init revisions tested: 2, total time: 30m9.444222552s (build: 15m31.428167353s, test: 13m43.65846108s) the crash still happens on HEAD commit msg: Linux 4.14.221 crash: INFO: task hung in hub_port_init vhci_hcd: cannot find a urb of seqnum 0 max seqnum 2 vhci_hcd: stop threads vhci_hcd: release socket vhci_hcd: disconnect device vhci_hcd vhci_hcd.0: port 1 already used INFO: task kworker/0:0:3 blocked for more than 140 seconds. vhci_hcd vhci_hcd.0: pdev(1) rhport(0) sockfd(3) Not tainted 4.14.221-syzkaller #0 vhci_hcd vhci_hcd.0: devid(0) speed(2) speed_str(full-speed) vhci_hcd vhci_hcd.0: port 1 already used "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. vhci_hcd: cannot find a urb of seqnum 0 max seqnum 2 kworker/0:0 D25712 3 2 0x80000000 Workqueue: usb_hub_wq hub_event Call Trace: vhci_hcd vhci_hcd.0: port 1 already used context_switch kernel/sched/core.c:2808 [inline] __schedule+0x824/0x1ee0 kernel/sched/core.c:3384 vhci_hcd: stop threads vhci_hcd: release socket vhci_hcd vhci_hcd.0: pdev(5) rhport(0) sockfd(3) vhci_hcd vhci_hcd.0: devid(0) speed(2) speed_str(full-speed) vhci_hcd vhci_hcd.0: pdev(2) rhport(0) sockfd(3) schedule+0x7f/0x1b0 kernel/sched/core.c:3428 vhci_hcd vhci_hcd.0: devid(0) speed(2) speed_str(full-speed) vhci_hcd: disconnect device vhci_hcd vhci_hcd.0: port 1 already used vhci_hcd: cannot find a urb of seqnum 0 max seqnum 2 usb_kill_urb drivers/usb/core/urb.c:691 [inline] usb_kill_urb+0x193/0x210 drivers/usb/core/urb.c:683 vhci_hcd: stop threads vhci_hcd: connection closed vhci_hcd: release socket usb_start_wait_urb+0x1fb/0x260 drivers/usb/core/message.c:62 vhci_hcd vhci_hcd.0: pdev(3) rhport(0) sockfd(3) vhci_hcd vhci_hcd.0: devid(0) speed(2) speed_str(full-speed) vhci_hcd: disconnect device vhci_hcd: stop threads usb_internal_control_msg drivers/usb/core/message.c:100 [inline] usb_control_msg+0x31b/0x550 drivers/usb/core/message.c:151 vhci_hcd: release socket vhci_hcd: connection closed vhci_hcd: disconnect device vhci_hcd: stop threads vhci_hcd: release socket hub_port_init+0x6a5/0x2640 drivers/usb/core/hub.c:4555 vhci_hcd: disconnect device hub_port_connect drivers/usb/core/hub.c:4905 [inline] hub_port_connect_change drivers/usb/core/hub.c:5088 [inline] port_event drivers/usb/core/hub.c:5194 [inline] hub_event+0x1322/0x3260 drivers/usb/core/hub.c:5274 process_one_work+0x74f/0x1620 kernel/workqueue.c:2116 worker_thread+0xcc/0xee0 kernel/workqueue.c:2250 kthread+0x338/0x400 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 INFO: task kworker/0:1:25 blocked for more than 140 seconds. Not tainted 4.14.221-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:1 D26320 25 2 0x80000000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x824/0x1ee0 kernel/sched/core.c:3384 vhci_hcd vhci_hcd.0: port 1 already used schedule+0x7f/0x1b0 kernel/sched/core.c:3428 usb_kill_urb drivers/usb/core/urb.c:691 [inline] usb_kill_urb+0x193/0x210 drivers/usb/core/urb.c:683 usb_start_wait_urb+0x1fb/0x260 drivers/usb/core/message.c:62 vhci_hcd vhci_hcd.0: pdev(4) rhport(0) sockfd(3) usb_internal_control_msg drivers/usb/core/message.c:100 [inline] usb_control_msg+0x31b/0x550 drivers/usb/core/message.c:151 vhci_hcd vhci_hcd.0: devid(0) speed(2) speed_str(full-speed) vhci_hcd: cannot find a urb of seqnum 0 max seqnum 2 hub_port_init+0x6a5/0x2640 drivers/usb/core/hub.c:4555 hub_port_connect drivers/usb/core/hub.c:4905 [inline] hub_port_connect_change drivers/usb/core/hub.c:5088 [inline] port_event drivers/usb/core/hub.c:5194 [inline] hub_event+0x1322/0x3260 drivers/usb/core/hub.c:5274 process_one_work+0x74f/0x1620 kernel/workqueue.c:2116 vhci_hcd: stop threads vhci_hcd vhci_hcd.0: port 1 already used vhci_hcd: release socket worker_thread+0xcc/0xee0 kernel/workqueue.c:2250 vhci_hcd: disconnect device kthread+0x338/0x400 kernel/kthread.c:232 vhci_hcd vhci_hcd.0: pdev(0) rhport(0) sockfd(3) vhci_hcd vhci_hcd.0: devid(0) speed(2) speed_str(full-speed) vhci_hcd: cannot find a urb of seqnum 0 max seqnum 2 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 vhci_hcd vhci_hcd.0: port 1 already used INFO: task kworker/1:2:2656 blocked for more than 140 seconds. vhci_hcd: stop threads Not tainted 4.14.221-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/1:2 D26168 2656 2 0x80000000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x824/0x1ee0 kernel/sched/core.c:3384 schedule+0x7f/0x1b0 kernel/sched/core.c:3428 usb_kill_urb drivers/usb/core/urb.c:691 [inline] usb_kill_urb+0x193/0x210 drivers/usb/core/urb.c:683 vhci_hcd: release socket vhci_hcd: disconnect device vhci_hcd vhci_hcd.0: pdev(1) rhport(0) sockfd(3) usb_start_wait_urb+0x1fb/0x260 drivers/usb/core/message.c:62 vhci_hcd vhci_hcd.0: devid(0) speed(2) speed_str(full-speed) vhci_hcd: cannot find a urb of seqnum 0 max seqnum 2 vhci_hcd: stop threads vhci_hcd: release socket vhci_hcd: disconnect device usb_internal_control_msg drivers/usb/core/message.c:100 [inline] usb_control_msg+0x31b/0x550 drivers/usb/core/message.c:151 vhci_hcd vhci_hcd.0: port 1 already used vhci_hcd vhci_hcd.0: port 1 already used hub_port_init+0x6a5/0x2640 drivers/usb/core/hub.c:4555 vhci_hcd vhci_hcd.0: pdev(2) rhport(0) sockfd(3) hub_port_connect drivers/usb/core/hub.c:4905 [inline] hub_port_connect_change drivers/usb/core/hub.c:5088 [inline] port_event drivers/usb/core/hub.c:5194 [inline] hub_event+0x1322/0x3260 drivers/usb/core/hub.c:5274 vhci_hcd vhci_hcd.0: devid(0) speed(2) speed_str(full-speed) vhci_hcd vhci_hcd.0: pdev(5) rhport(0) sockfd(3) vhci_hcd vhci_hcd.0: devid(0) speed(2) speed_str(full-speed) vhci_hcd vhci_hcd.0: port 1 already used vhci_hcd: connection closed vhci_hcd: stop threads vhci_hcd vhci_hcd.0: pdev(3) rhport(0) sockfd(3) vhci_hcd vhci_hcd.0: devid(0) speed(2) speed_str(full-speed) process_one_work+0x74f/0x1620 kernel/workqueue.c:2116 vhci_hcd: cannot find a urb of seqnum 0 max seqnum 2 vhci_hcd: cannot find a urb of seqnum 0 max seqnum 2 vhci_hcd: release socket worker_thread+0xcc/0xee0 kernel/workqueue.c:2250 vhci_hcd: disconnect device kthread+0x338/0x400 kernel/kthread.c:232 vhci_hcd: stop threads vhci_hcd: release socket vhci_hcd: disconnect device ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 vhci_hcd: stop threads INFO: task kworker/0:2:2813 blocked for more than 140 seconds. Not tainted 4.14.221-syzkaller #0 vhci_hcd: release socket "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. vhci_hcd: disconnect device kworker/0:2 D26184 2813 2 0x80000000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x824/0x1ee0 kernel/sched/core.c:3384 schedule+0x7f/0x1b0 kernel/sched/core.c:3428 usb_kill_urb drivers/usb/core/urb.c:691 [inline] usb_kill_urb+0x193/0x210 drivers/usb/core/urb.c:683 usb_start_wait_urb+0x1fb/0x260 drivers/usb/core/message.c:62 vhci_hcd vhci_hcd.0: port 1 already used usb_internal_control_msg drivers/usb/core/message.c:100 [inline] usb_control_msg+0x31b/0x550 drivers/usb/core/message.c:151 vhci_hcd vhci_hcd.0: pdev(4) rhport(0) sockfd(3) vhci_hcd vhci_hcd.0: devid(0) speed(2) speed_str(full-speed) vhci_hcd: cannot find a urb of seqnum 0 max seqnum 2 hub_port_init+0x6a5/0x2640 drivers/usb/core/hub.c:4555 vhci_hcd: stop threads hub_port_connect drivers/usb/core/hub.c:4905 [inline] hub_port_connect_change drivers/usb/core/hub.c:5088 [inline] port_event drivers/usb/core/hub.c:5194 [inline] hub_event+0x1322/0x3260 drivers/usb/core/hub.c:5274 vhci_hcd vhci_hcd.0: port 1 already used vhci_hcd: release socket vhci_hcd: disconnect device process_one_work+0x74f/0x1620 kernel/workqueue.c:2116 worker_thread+0xcc/0xee0 kernel/workqueue.c:2250 kthread+0x338/0x400 kernel/kthread.c:232 vhci_hcd vhci_hcd.0: pdev(0) rhport(0) sockfd(3) vhci_hcd vhci_hcd.0: devid(0) speed(2) speed_str(full-speed) vhci_hcd: cannot find a urb of seqnum 0 max seqnum 2 vhci_hcd: stop threads ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 vhci_hcd: release socket INFO: task kworker/1:3:5809 blocked for more than 140 seconds. vhci_hcd vhci_hcd.0: port 1 already used Not tainted 4.14.221-syzkaller #0 vhci_hcd: disconnect device "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. vhci_hcd vhci_hcd.0: pdev(1) rhport(0) sockfd(3) kworker/1:3 D vhci_hcd vhci_hcd.0: devid(0) speed(2) speed_str(full-speed) vhci_hcd: cannot find a urb of seqnum 0 max seqnum 2 26096 5809 2 0x80000000 vhci_hcd: stop threads Workqueue: usb_hub_wq hub_event vhci_hcd: release socket Call Trace: vhci_hcd: disconnect device context_switch kernel/sched/core.c:2808 [inline] __schedule+0x824/0x1ee0 kernel/sched/core.c:3384 schedule+0x7f/0x1b0 kernel/sched/core.c:3428 usb_kill_urb drivers/usb/core/urb.c:691 [inline] usb_kill_urb+0x193/0x210 drivers/usb/core/urb.c:683 usb_start_wait_urb+0x1fb/0x260 drivers/usb/core/message.c:62 usb_internal_control_msg drivers/usb/core/message.c:100 [inline] usb_control_msg+0x31b/0x550 drivers/usb/core/message.c:151 vhci_hcd vhci_hcd.0: port 1 already used hub_port_init+0x6a5/0x2640 drivers/usb/core/hub.c:4555 hub_port_connect drivers/usb/core/hub.c:4905 [inline] hub_port_connect_change drivers/usb/core/hub.c:5088 [inline] port_event drivers/usb/core/hub.c:5194 [inline] hub_event+0x1322/0x3260 drivers/usb/core/hub.c:5274 process_one_work+0x74f/0x1620 kernel/workqueue.c:2116 vhci_hcd vhci_hcd.0: pdev(2) rhport(0) sockfd(3) vhci_hcd vhci_hcd.0: devid(0) speed(2) speed_str(full-speed) vhci_hcd vhci_hcd.0: port 1 already used worker_thread+0xcc/0xee0 kernel/workqueue.c:2250 vhci_hcd vhci_hcd.0: port 1 already used kthread+0x338/0x400 kernel/kthread.c:232 vhci_hcd: cannot find a urb of seqnum 0 max seqnum 2 vhci_hcd: stop threads vhci_hcd: release socket vhci_hcd: disconnect device vhci_hcd vhci_hcd.0: pdev(5) rhport(0) sockfd(3) vhci_hcd vhci_hcd.0: pdev(3) rhport(0) sockfd(3) vhci_hcd vhci_hcd.0: devid(0) speed(2) speed_str(full-speed) vhci_hcd vhci_hcd.0: devid(0) speed(2) speed_str(full-speed) vhci_hcd: cannot find a urb of seqnum 0 max seqnum 2 vhci_hcd: stop threads ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 vhci_hcd: release socket INFO: task kworker/0:5:7215 blocked for more than 140 seconds. vhci_hcd: disconnect device Not tainted 4.14.221-syzkaller #0 vhci_hcd: connection closed "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:5 D25328 7215 2 0x80000000 vhci_hcd: stop threads Workqueue: usb_hub_wq hub_event vhci_hcd: release socket Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x824/0x1ee0 kernel/sched/core.c:3384 schedule+0x7f/0x1b0 kernel/sched/core.c:3428 usb_kill_urb drivers/usb/core/urb.c:691 [inline] usb_kill_urb+0x193/0x210 drivers/usb/core/urb.c:683 vhci_hcd: disconnect device vhci_hcd vhci_hcd.0: port 1 already used usb_start_wait_urb+0x1fb/0x260 drivers/usb/core/message.c:62 usb_internal_control_msg drivers/usb/core/message.c:100 [inline] usb_control_msg+0x31b/0x550 drivers/usb/core/message.c:151 vhci_hcd vhci_hcd.0: pdev(4) rhport(0) sockfd(3) hub_port_init+0x6a5/0x2640 drivers/usb/core/hub.c:4555 vhci_hcd vhci_hcd.0: devid(0) speed(2) speed_str(full-speed) hub_port_connect drivers/usb/core/hub.c:4905 [inline] hub_port_connect_change drivers/usb/core/hub.c:5088 [inline] port_event drivers/usb/core/hub.c:5194 [inline] hub_event+0x1322/0x3260 drivers/usb/core/hub.c:5274 vhci_hcd: cannot find a urb of seqnum 0 max seqnum 2 vhci_hcd vhci_hcd.0: port 1 already used vhci_hcd: stop threads process_one_work+0x74f/0x1620 kernel/workqueue.c:2116 vhci_hcd: release socket worker_thread+0xcc/0xee0 kernel/workqueue.c:2250 kthread+0x338/0x400 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Showing all locks held in the system: vhci_hcd: disconnect device vhci_hcd vhci_hcd.0: pdev(0) rhport(0) sockfd(3) 5 locks held by kworker/0:0/3: vhci_hcd vhci_hcd.0: devid(0) speed(2) speed_str(full-speed) #0: ("usb_hub_wq"){+.+.}, at: [] process_one_work+0x681/0x1620 kernel/workqueue.c:2087 #1: ((&hub->events)){+.+.}, at: [] process_one_work+0x6b4/0x1620 kernel/workqueue.c:2091 #2: (&dev->mutex){....}, at: [] device_lock include/linux/device.h:1081 [inline] #2: (&dev->mutex){....}, at: [] hub_event+0x120/0x3260 drivers/usb/core/hub.c:5220 #3: (&port_dev->status_lock){+.+.}, at: [] usb_lock_port drivers/usb/core/hub.c:2934 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4904 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5088 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] port_event drivers/usb/core/hub.c:5194 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_event+0x1307/0x3260 drivers/usb/core/hub.c:5274 #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_init+0x145/0x2640 drivers/usb/core/hub.c:4429 5 locks held by kworker/0:1/25: #0: ("usb_hub_wq"){+.+.}, at: [] process_one_work+0x681/0x1620 kernel/workqueue.c:2087 #1: ((&hub->events)){+.+.}, at: [] process_one_work+0x6b4/0x1620 kernel/workqueue.c:2091 #2: (&dev->mutex){....}, at: [] device_lock include/linux/device.h:1081 [inline] #2: (&dev->mutex){....}, at: [] hub_event+0x120/0x3260 drivers/usb/core/hub.c:5220 #3: (&port_dev->status_lock){+.+.}, at: [] usb_lock_port drivers/usb/core/hub.c:2934 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4904 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5088 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] port_event drivers/usb/core/hub.c:5194 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_event+0x1307/0x3260 drivers/usb/core/hub.c:5274 #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_init+0x145/0x2640 drivers/usb/core/hub.c:4429 1 lock held by khungtaskd/1066: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4548 5 locks held by kworker/1:2/2656: #0: ("usb_hub_wq"){+.+.}, at: [] process_one_work+0x681/0x1620 kernel/workqueue.c:2087 #1: ((&hub->events)){+.+.}, at: [] process_one_work+0x6b4/0x1620 kernel/workqueue.c:2091 #2: (&dev->mutex){....}, at: [] device_lock include/linux/device.h:1081 [inline] #2: (&dev->mutex){....}, at: [] hub_event+0x120/0x3260 drivers/usb/core/hub.c:5220 #3: (&port_dev->status_lock){+.+.}, at: [] usb_lock_port drivers/usb/core/hub.c:2934 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4904 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5088 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] port_event drivers/usb/core/hub.c:5194 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_event+0x1307/0x3260 drivers/usb/core/hub.c:5274 #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_init+0x145/0x2640 drivers/usb/core/hub.c:4429 5 locks held by kworker/0:2/2813: #0: ("usb_hub_wq"){+.+.}, at: [] process_one_work+0x681/0x1620 kernel/workqueue.c:2087 #1: ((&hub->events)){+.+.}, at: [] process_one_work+0x6b4/0x1620 kernel/workqueue.c:2091 #2: (&dev->mutex){....}, at: [] device_lock include/linux/device.h:1081 [inline] #2: (&dev->mutex){....}, at: [] hub_event+0x120/0x3260 drivers/usb/core/hub.c:5220 #3: (&port_dev->status_lock){+.+.}, at: [] usb_lock_port drivers/usb/core/hub.c:2934 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4904 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5088 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] port_event drivers/usb/core/hub.c:5194 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_event+0x1307/0x3260 drivers/usb/core/hub.c:5274 #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_init+0x145/0x2640 drivers/usb/core/hub.c:4429 5 locks held by kworker/1:3/5809: #0: ("usb_hub_wq"){+.+.}, at: [] process_one_work+0x681/0x1620 kernel/workqueue.c:2087 #1: ((&hub->events)){+.+.}, at: [] process_one_work+0x6b4/0x1620 kernel/workqueue.c:2091 #2: (&dev->mutex){....}, at: [] device_lock include/linux/device.h:1081 [inline] #2: (&dev->mutex){....}, at: [] hub_event+0x120/0x3260 drivers/usb/core/hub.c:5220 #3: (&port_dev->status_lock){+.+.}, at: [] usb_lock_port drivers/usb/core/hub.c:2934 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4904 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5088 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] port_event drivers/usb/core/hub.c:5194 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_event+0x1307/0x3260 drivers/usb/core/hub.c:5274 #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_init+0x145/0x2640 drivers/usb/core/hub.c:4429 5 locks held by kworker/0:5/7215: #0: ("usb_hub_wq"){+.+.}, at: [] process_one_work+0x681/0x1620 kernel/workqueue.c:2087 #1: ((&hub->events)){+.+.}, at: [] process_one_work+0x6b4/0x1620 kernel/workqueue.c:2091 #2: (&dev->mutex){....}, at: [] device_lock include/linux/device.h:1081 [inline] #2: (&dev->mutex){....}, at: [] hub_event+0x120/0x3260 drivers/usb/core/hub.c:5220 #3: (&port_dev->status_lock){+.+.}, at: [] usb_lock_port drivers/usb/core/hub.c:2934 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4904 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5088 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] port_event drivers/usb/core/hub.c:5194 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_event+0x1307/0x3260 drivers/usb/core/hub.c:5274 #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_init+0x145/0x2640 drivers/usb/core/hub.c:4429 4 locks held by syz-executor.0/22820: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0x8e/0xc0 fs/file.c:769 #1: (sb_writers#5){.+.+}, at: [] file_start_write include/linux/fs.h:2712 [inline] #1: (sb_writers#5){.+.+}, at: [] vfs_write+0x37c/0x4f0 fs/read_write.c:543 #2: (&of->mutex){+.+.}, at: [] kernfs_fop_write+0x1ab/0x410 fs/kernfs/file.c:307 #3: (kn->count#131){.+.+}, at: [] kernfs_fop_write+0x1ce/0x410 fs/kernfs/file.c:308 ============================================= vhci_hcd vhci_hcd.0: port 1 already used NMI backtrace for cpu 1 CPU: 1 PID: 1066 Comm: khungtaskd Not tainted 4.14.221-syzkaller #0 vhci_hcd: connection closed Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 vhci_hcd: stop threads Call Trace: vhci_hcd: release socket __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x14b/0x1e7 lib/dump_stack.c:58 vhci_hcd: disconnect device nmi_cpu_backtrace.cold.0+0x3c/0x78 lib/nmi_backtrace.c:101 vhci_hcd vhci_hcd.0: pdev(1) rhport(0) sockfd(3) nmi_trigger_cpumask_backtrace+0xf5/0x120 lib/nmi_backtrace.c:62 vhci_hcd vhci_hcd.0: devid(0) speed(2) speed_str(full-speed) arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x51b/0xa70 kernel/hung_task.c:274 vhci_hcd: cannot find a urb of seqnum 0 max seqnum 2 kthread+0x338/0x400 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 1 to CPUs 0: vhci_hcd: stop threads NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: kworker/u4:2 Not tainted 4.14.221-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: usbip_event event_handler task: ffff8881f4e88080 task.stack: ffff8881f4e90000 RIP: 0010:trace_hardirqs_off_caller+0x1f4/0x2a0 kernel/locking/lockdep.c:2970 RSP: 0018:ffff8881f6607ce8 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffff8881f4e88080 RCX: 0000000000000000 RDX: 1ffff1103e9d111a RSI: 0000000000000000 RDI: ffff8881f4e888d0 RBP: ffff8881f6607d00 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000078 R11: ffff8881f4e88080 R12: ffff8881f4e88080 R13: ffffffff866c0763 R14: ffffffff89b6b1c8 R15: ffff8881f6607de0 FS: 0000000000000000(0000) GS:ffff8881f6600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020004780 CR3: 0000000007e6a006 CR4: 00000000001606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_hardirqs_off+0xd/0x10 kernel/locking/lockdep.c:2975 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irqrestore+0x63/0xd0 kernel/locking/spinlock.c:192 debug_object_deactivate lib/debugobjects.c:530 [inline] debug_object_deactivate+0x1f8/0x300 lib/debugobjects.c:491 debug_hrtimer_deactivate kernel/time/hrtimer.c:406 [inline] debug_deactivate kernel/time/hrtimer.c:453 [inline] __run_hrtimer kernel/time/hrtimer.c:1193 [inline] __hrtimer_run_queues+0x1ba/0xad0 kernel/time/hrtimer.c:1287 hrtimer_interrupt+0x1ae/0x600 kernel/time/hrtimer.c:1321 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1079 [inline] smp_apic_timer_interrupt+0x11f/0x5d0 arch/x86/kernel/apic/apic.c:1104 apic_timer_interrupt+0x9a/0xa0 arch/x86/entry/entry_64.S:793 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:779 [inline] RIP: 0010:console_trylock_spinning kernel/printk/printk.c:1685 [inline] RIP: 0010:vprintk_emit+0x42c/0x4e0 kernel/printk/printk.c:1922 RSP: 0018:ffff8881f4e97b40 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff10 RAX: dffffc0000000000 RBX: 0000000000000286 RCX: 1ffff1103e9d112a RDX: 0000000000000000 RSI: ffff8881f4e88930 RDI: 0000000000000286 RBP: ffff8881f4e97b90 R08: ffff8881f4e88950 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 1ffffffff0fe2bc0 R13: 1ffffffff0fe2bc2 R14: 0000000000000000 R15: 1ffffffff0fe2bc1 vprintk_default+0x1a/0x20 kernel/printk/printk.c:1963 vprintk_func+0x49/0x130 kernel/printk/printk_safe.c:401 printk+0x91/0xab kernel/printk/printk.c:1996 vhci_shutdown_connection.cold.6+0x32/0x790 drivers/usb/usbip/vhci_hcd.c:1040 event_handler+0x169/0x360 drivers/usb/usbip/usbip_event.c:92 process_one_work+0x74f/0x1620 kernel/workqueue.c:2116 worker_thread+0xcc/0xee0 kernel/workqueue.c:2250 kthread+0x338/0x400 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Code: 00 fc ff df 44 89 a3 30 08 00 00 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 85 00 00 00 44 89 a3 4c 08 00 00 <5b> 41 5c 41 5d 5d c3 e8 80 7a b7 01 85 c0 74 f0 48 c7 c7 80 ea vhci_hcd vhci_hcd.0: port 1 already used vhci_hcd: release socket