diff options
| -rw-r--r-- | drivers/usb/gadget/function/f_uvc.c | 28 |
1 files changed, 21 insertions, 7 deletions
diff --git a/drivers/usb/gadget/function/f_uvc.c b/drivers/usb/gadget/function/f_uvc.c index 8d404d88391c..73dc7e42875f 100644 --- a/drivers/usb/gadget/function/f_uvc.c +++ b/drivers/usb/gadget/function/f_uvc.c @@ -769,6 +769,16 @@ uvc_function_bind(struct usb_configuration *c, struct usb_function *f) uvc_ss_streaming_ep.bEndpointAddress = uvc->video.ep->address; /* + * Hold opts->lock across both the XU string-descriptor fixup below and + * the descriptor-copy block further down. Without this, configfs + * uvcg_extension_drop() (which takes opts->lock) can race with the + * list_for_each_entry() walks here and inside uvc_copy_descriptors(), + * leading to a UAF on a freed struct uvcg_extension. See + * drivers/usb/gadget/function/uvc_configfs.c::uvcg_extension_drop(). + */ + mutex_lock(&opts->lock); + + /* * XUs can have an arbitrary string descriptor describing them. If they * have one pick up the ID. */ @@ -785,7 +795,7 @@ uvc_function_bind(struct usb_configuration *c, struct usb_function *f) ARRAY_SIZE(uvc_en_us_strings)); if (IS_ERR(us)) { ret = PTR_ERR(us); - goto error; + goto error_unlock; } uvc_iad.iFunction = opts->iad_index ? cdev->usb_strings[opts->iad_index].id : @@ -799,14 +809,14 @@ uvc_function_bind(struct usb_configuration *c, struct usb_function *f) /* Allocate interface IDs. */ if ((ret = usb_interface_id(c, f)) < 0) - goto error; + goto error_unlock; uvc_iad.bFirstInterface = ret; uvc_control_intf.bInterfaceNumber = ret; uvc->control_intf = ret; opts->control_interface = ret; if ((ret = usb_interface_id(c, f)) < 0) - goto error; + goto error_unlock; uvc_streaming_intf_alt0.bInterfaceNumber = ret; uvc_streaming_intf_alt1.bInterfaceNumber = ret; uvc->streaming_intf = ret; @@ -817,30 +827,32 @@ uvc_function_bind(struct usb_configuration *c, struct usb_function *f) if (IS_ERR(f->fs_descriptors)) { ret = PTR_ERR(f->fs_descriptors); f->fs_descriptors = NULL; - goto error; + goto error_unlock; } f->hs_descriptors = uvc_copy_descriptors(uvc, USB_SPEED_HIGH); if (IS_ERR(f->hs_descriptors)) { ret = PTR_ERR(f->hs_descriptors); f->hs_descriptors = NULL; - goto error; + goto error_unlock; } f->ss_descriptors = uvc_copy_descriptors(uvc, USB_SPEED_SUPER); if (IS_ERR(f->ss_descriptors)) { ret = PTR_ERR(f->ss_descriptors); f->ss_descriptors = NULL; - goto error; + goto error_unlock; } f->ssp_descriptors = uvc_copy_descriptors(uvc, USB_SPEED_SUPER_PLUS); if (IS_ERR(f->ssp_descriptors)) { ret = PTR_ERR(f->ssp_descriptors); f->ssp_descriptors = NULL; - goto error; + goto error_unlock; } + mutex_unlock(&opts->lock); + /* Preallocate control endpoint request. */ uvc->control_req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL); uvc->control_buf = kmalloc(UVC_MAX_REQUEST_SIZE, GFP_KERNEL); @@ -872,6 +884,8 @@ uvc_function_bind(struct usb_configuration *c, struct usb_function *f) return 0; +error_unlock: + mutex_unlock(&opts->lock); v4l2_error: v4l2_device_unregister(&uvc->v4l2_dev); error: |