Hello, When fuzzing the Linux kernel driver v5.18.0, the following crash was triggered. HEAD commit: 4b0986a3613c92f4ec1bdc7f60ec66fea135991f (HEAD, tag: v5.18) git tree: upstream kernel config: https://pastebin.com/KecL2gaG C reproducer: https://pastebin.com/ZX3ZtZZ4 console output: https://pastebin.com/UYyiRL3E Basically, in the c reproducer, we use the gadget module to emulate the process of attaching a usb device (vendor id: 0x13d3, product id: 0x3340, with function: ms_null and midi_null). To reproduce this crash, we utilize a third-party library to emulate the attaching process: https://github.com/linux-usb-gadgets/libusbgx. Just clone this repository, make install it, and compile the c reproducer with ``` gcc crash.c -lusbgx -o crash ``` will do the trick. It seems that there is a deadlock happened in function usb_stor_post_reset The crash report is as follow: ``` usb 7-1: r8712u: Loading firmware from "rtlwifi/rtl8712u.bin" ============================================ WARNING: possible recursive locking detected 5.18.0 #3 Not tainted -------------------------------------------- kworker/1:3/1205 is trying to acquire lock: ffff888018638db8 (&us_interface_key[i]){+.+.}-{3:3}, at: usb_stor_pre_reset+0x35/0x40 drivers/usb/storage/usb.c:230 but task is already holding lock: ffff888018638db8 (&us_interface_key[i]){+.+.}-{3:3}, at: usb_stor_pre_reset+0x35/0x40 drivers/usb/storage/usb.c:230 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&us_interface_key[i]); lock(&us_interface_key[i]); *** DEADLOCK *** May be due to missing lock nesting notation 7 locks held by kworker/1:3/1205: #0: ffff888105a82d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888105a82d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888105a82d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline] #0: ffff888105a82d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline] #0: ffff888105a82d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline] #0: ffff888105a82d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x8b0/0x1650 kernel/workqueue.c:2260 #1: ffffc900004f7db0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x8e4/0x1650 kernel/workqueue.c:2264 #2: ffff88810be5a220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline] #2: ffff88810be5a220 (&dev->mutex){....}-{3:3}, at: hub_event+0x1c1/0x4170 drivers/usb/core/hub.c:5691 #3: ffff888110850220 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7b/0x3f0 drivers/base/dd.c:965 #4: ffff888018a871a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7b/0x3f0 drivers/base/dd.c:965 #5: ffff888018638db8 (&us_interface_key[i]){+.+.}-{3:3}, at: usb_stor_pre_reset+0x35/0x40 drivers/usb/storage/usb.c:230 #6: ffff8881085711a8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0x23/0x2f0 drivers/base/dd.c:1245 stack backtrace: CPU: 1 PID: 1205 Comm: kworker/1:3 Not tainted 5.18.0 #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Workqueue: usb_hub_wq hub_event Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2988 [inline] check_deadlock kernel/locking/lockdep.c:3031 [inline] validate_chain kernel/locking/lockdep.c:3816 [inline] __lock_acquire.cold+0x152/0x3ca kernel/locking/lockdep.c:5053 lock_acquire kernel/locking/lockdep.c:5665 [inline] lock_acquire+0x1ab/0x520 kernel/locking/lockdep.c:5630 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x14f/0x1610 kernel/locking/mutex.c:747 usb_stor_pre_reset+0x35/0x40 drivers/usb/storage/usb.c:230 usb_reset_device+0x37d/0x9a0 drivers/usb/core/hub.c:6109 r871xu_dev_remove+0x21a/0x270 drivers/staging/rtl8712/usb_intf.c:622 usb_unbind_interface+0x1bd/0x890 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:545 [inline] device_remove+0x11f/0x170 drivers/base/dd.c:537 __device_release_driver drivers/base/dd.c:1222 [inline] device_release_driver_internal+0x1a7/0x2f0 drivers/base/dd.c:1248 usb_driver_release_interface+0x102/0x180 drivers/usb/core/driver.c:627 usb_forced_unbind_intf+0x4d/0xa0 drivers/usb/core/driver.c:1118 usb_reset_device+0x39b/0x9a0 drivers/usb/core/hub.c:6114 rt2x00usb_probe+0x53/0x7f0 usb_probe_interface+0x310/0x800 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:555 [inline] really_probe drivers/base/dd.c:634 [inline] really_probe+0x23e/0xa00 drivers/base/dd.c:579 __driver_probe_device+0x338/0x4d0 drivers/base/dd.c:764 driver_probe_device+0x4c/0x1a0 drivers/base/dd.c:794 __device_attach_driver+0x20b/0x2f0 drivers/base/dd.c:917 bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:427 __device_attach+0x26d/0x3f0 drivers/base/dd.c:989 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:487 device_add+0xc45/0x1d40 drivers/base/core.c:3412 usb_set_configuration+0x1019/0x1900 drivers/usb/core/message.c:2170 usb_generic_driver_probe+0x9d/0xe0 drivers/usb/core/generic.c:238 usb_probe_device+0xd9/0x2a0 drivers/usb/core/driver.c:293 call_driver_probe drivers/base/dd.c:555 [inline] really_probe drivers/base/dd.c:634 [inline] really_probe+0x23e/0xa00 drivers/base/dd.c:579 __driver_probe_device+0x338/0x4d0 drivers/base/dd.c:764 driver_probe_device+0x4c/0x1a0 drivers/base/dd.c:794 __device_attach_driver+0x20b/0x2f0 drivers/base/dd.c:917 bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:427 __device_attach+0x26d/0x3f0 drivers/base/dd.c:989 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:487 device_add+0xc45/0x1d40 drivers/base/core.c:3412 usb_new_device.cold+0x4b8/0x10ca drivers/usb/core/hub.c:2566 hub_port_connect drivers/usb/core/hub.c:5359 [inline] hub_port_connect_change drivers/usb/core/hub.c:5507 [inline] port_event drivers/usb/core/hub.c:5663 [inline] hub_event+0x231e/0x4170 drivers/usb/core/hub.c:5745 process_one_work+0x9cc/0x1650 kernel/workqueue.c:2289 worker_thread+0x623/0x1070 kernel/workqueue.c:2436 kthread+0x2ef/0x3a0 kernel/kthread.c:346 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302 </TASK> ```
