Reference: https://syzkaller.appspot.com/bug?extid=4b3f8190f6e13b3efd74 Reference: https://syzkaller.appspot.com/bug?extid=1cb937c125adb93fad2d The radio-shark driver just assumes that the endpoints it uses will be present, without checking. This adds an appropriate check. Alan Stern #syz test: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ v6.2 drivers/usb/core/usb.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/usb.h | 7 ++++ 2 files changed, 77 insertions(+) Index: usb-devel/drivers/usb/core/usb.c =================================================================== --- usb-devel.orig/drivers/usb/core/usb.c +++ usb-devel/drivers/usb/core/usb.c @@ -207,6 +207,76 @@ int usb_find_common_endpoints_reverse(st EXPORT_SYMBOL_GPL(usb_find_common_endpoints_reverse); /** + * usb_find_endpoint() - Given an endpoint address, search for the endpoint's + * usb_host_endpoint structure in an interface's current altsetting. + * @intf: the interface whose current altsetting should be searched + * @ep_addr: the endpoint address (number and direction) to find + * + * Search the altsetting's list of endpoints for one with the specified address. + * + * Return: Pointer to the usb_host_endpoint if found, %NULL otherwise. + */ +struct usb_host_endpoint __must_check *usb_find_endpoint( + const struct usb_interface *intf, unsigned int ep_addr) +{ + int n; + struct usb_host_endpoint *ep; + + n = intf->cur_altsetting->desc.bNumEndpoints; + ep = intf->cur_altsetting->endpoint; + for (; n > 0; (--n, ++ep)) { + if (ep->desc.bEndpointAddress == ep_addr) + return ep; + } + return NULL; +} +EXPORT_SYMBOL_GPL(usb_find_endpoint); + +/** + * usb_check_bulk_endpoint - Check whether an interface's current altsetting + * contains a bulk endpoint with the given address. + * @intf: the interface whose current altsetting should be searched + * @ep_addr: the endpoint address (number and direction) to look for + * + * Search for an endpoint with the specified address and check its type. + * + * Return: %true if the endpoint is found and is bulk, %false otherwise. + */ +bool usb_check_bulk_endpoint( + const struct usb_interface *intf, unsigned int ep_addr) +{ + const struct usb_host_endpoint *ep; + + ep = usb_find_endpoint(intf, ep_addr); + if (!ep) + return false; + return usb_endpoint_xfer_bulk(&ep->desc); +} +EXPORT_SYMBOL_GPL(usb_check_bulk_endpoint); + +/** + * usb_check_int_endpoint - Check whether an interface's current altsetting + * contains an interrupt endpoint with the given address. + * @intf: the interface whose current altsetting should be searched + * @ep_addr: the endpoint address (number and direction) to look for + * + * Search for an endpoint with the specified address and check its type. + * + * Return: %true if the endpoint is found and is interrupt, %false otherwise. + */ +bool usb_check_int_endpoint( + const struct usb_interface *intf, unsigned int ep_addr) +{ + const struct usb_host_endpoint *ep; + + ep = usb_find_endpoint(intf, ep_addr); + if (!ep) + return false; + return usb_endpoint_xfer_int(&ep->desc); +} +EXPORT_SYMBOL_GPL(usb_check_int_endpoint); + +/** * usb_find_alt_setting() - Given a configuration, find the alternate setting * for the given interface. * @config: the configuration to search (not necessarily the current config). Index: usb-devel/include/linux/usb.h =================================================================== --- usb-devel.orig/include/linux/usb.h +++ usb-devel/include/linux/usb.h @@ -292,6 +292,13 @@ void usb_put_intf(struct usb_interface * #define USB_MAXINTERFACES 32 #define USB_MAXIADS (USB_MAXINTERFACES/2) +struct usb_host_endpoint __must_check *usb_find_endpoint( + const struct usb_interface *intf, unsigned int ep_addr); +bool usb_check_bulk_endpoint( + const struct usb_interface *intf, unsigned int ep_addr); +bool usb_check_int_endpoint( + const struct usb_interface *intf, unsigned int ep_addr); + /* * USB Resume Timer: Every Host controller driver should drive the resume * signalling on the bus for the amount of time defined by this macro. drivers/media/radio/radio-shark.c | 7 +++++++ drivers/media/radio/radio-shark2.c | 7 +++++++ 2 files changed, 14 insertions(+) Index: usb-devel/drivers/media/radio/radio-shark.c =================================================================== --- usb-devel.orig/drivers/media/radio/radio-shark.c +++ usb-devel/drivers/media/radio/radio-shark.c @@ -317,6 +317,13 @@ static int usb_shark_probe(struct usb_in struct shark_device *shark; int retval = -ENOMEM; + /* Are the expected endpoints present? */ + if (!usb_check_int_endpoint(intf, SHARK_IN_EP | USB_DIR_IN) || + !usb_check_int_endpoint(intf, SHARK_OUT_EP | USB_DIR_OUT)) { + dev_err(&intf->dev, "Invalid radioSHARK device\n"); + return -EINVAL; + } + shark = kzalloc(sizeof(struct shark_device), GFP_KERNEL); if (!shark) return retval; Index: usb-devel/drivers/media/radio/radio-shark2.c =================================================================== --- usb-devel.orig/drivers/media/radio/radio-shark2.c +++ usb-devel/drivers/media/radio/radio-shark2.c @@ -283,6 +283,13 @@ static int usb_shark_probe(struct usb_in struct shark_device *shark; int retval = -ENOMEM; + /* Are the expected endpoints present? */ + if (!usb_check_int_endpoint(intf, SHARK_IN_EP | USB_DIR_IN) || + !usb_check_int_endpoint(intf, SHARK_OUT_EP | USB_DIR_OUT)) { + dev_err(&intf->dev, "Invalid radioSHARK2 device\n"); + return -EINVAL; + } + shark = kzalloc(sizeof(struct shark_device), GFP_KERNEL); if (!shark) return retval;
