USB: core: Add type-specific length check of BOS descriptors

As most of BOS descriptors are longer in length than their header
'struct usb_dev_cap_header', comparing solely with it is not sufficient
to avoid out-of-bounds access to BOS descriptors.

This patch adds descriptor type specific length check in
usb_get_bos_descriptor() to fix the issue.

Signed-off-by: Masakazu Mokuno <masakazu.mokuno@gmail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Masakazu Mokuno 2017-11-10 01:25:50 +09:00 committed by Greg Kroah-Hartman
parent 1d5a31582e
commit 81cf4a4536
2 changed files with 27 additions and 4 deletions

View File

@ -905,14 +905,25 @@ void usb_release_bos_descriptor(struct usb_device *dev)
} }
} }
static const __u8 bos_desc_len[256] = {
[USB_CAP_TYPE_WIRELESS_USB] = USB_DT_USB_WIRELESS_CAP_SIZE,
[USB_CAP_TYPE_EXT] = USB_DT_USB_EXT_CAP_SIZE,
[USB_SS_CAP_TYPE] = USB_DT_USB_SS_CAP_SIZE,
[USB_SSP_CAP_TYPE] = USB_DT_USB_SSP_CAP_SIZE(1),
[CONTAINER_ID_TYPE] = USB_DT_USB_SS_CONTN_ID_SIZE,
[USB_PTM_CAP_TYPE] = USB_DT_USB_PTM_ID_SIZE,
};
/* Get BOS descriptor set */ /* Get BOS descriptor set */
int usb_get_bos_descriptor(struct usb_device *dev) int usb_get_bos_descriptor(struct usb_device *dev)
{ {
struct device *ddev = &dev->dev; struct device *ddev = &dev->dev;
struct usb_bos_descriptor *bos; struct usb_bos_descriptor *bos;
struct usb_dev_cap_header *cap; struct usb_dev_cap_header *cap;
struct usb_ssp_cap_descriptor *ssp_cap;
unsigned char *buffer; unsigned char *buffer;
int length, total_len, num, i; int length, total_len, num, i, ssac;
__u8 cap_type;
int ret; int ret;
bos = kzalloc(sizeof(struct usb_bos_descriptor), GFP_KERNEL); bos = kzalloc(sizeof(struct usb_bos_descriptor), GFP_KERNEL);
@ -965,7 +976,13 @@ int usb_get_bos_descriptor(struct usb_device *dev)
dev->bos->desc->bNumDeviceCaps = i; dev->bos->desc->bNumDeviceCaps = i;
break; break;
} }
cap_type = cap->bDevCapabilityType;
length = cap->bLength; length = cap->bLength;
if (bos_desc_len[cap_type] && length < bos_desc_len[cap_type]) {
dev->bos->desc->bNumDeviceCaps = i;
break;
}
total_len -= length; total_len -= length;
if (cap->bDescriptorType != USB_DT_DEVICE_CAPABILITY) { if (cap->bDescriptorType != USB_DT_DEVICE_CAPABILITY) {
@ -973,7 +990,7 @@ int usb_get_bos_descriptor(struct usb_device *dev)
continue; continue;
} }
switch (cap->bDevCapabilityType) { switch (cap_type) {
case USB_CAP_TYPE_WIRELESS_USB: case USB_CAP_TYPE_WIRELESS_USB:
/* Wireless USB cap descriptor is handled by wusb */ /* Wireless USB cap descriptor is handled by wusb */
break; break;
@ -986,8 +1003,11 @@ int usb_get_bos_descriptor(struct usb_device *dev)
(struct usb_ss_cap_descriptor *)buffer; (struct usb_ss_cap_descriptor *)buffer;
break; break;
case USB_SSP_CAP_TYPE: case USB_SSP_CAP_TYPE:
dev->bos->ssp_cap = ssp_cap = (struct usb_ssp_cap_descriptor *)buffer;
(struct usb_ssp_cap_descriptor *)buffer; ssac = (le32_to_cpu(ssp_cap->bmAttributes) &
USB_SSP_SUBLINK_SPEED_ATTRIBS) + 1;
if (length >= USB_DT_USB_SSP_CAP_SIZE(ssac))
dev->bos->ssp_cap = ssp_cap;
break; break;
case CONTAINER_ID_TYPE: case CONTAINER_ID_TYPE:
dev->bos->ss_id = dev->bos->ss_id =

View File

@ -880,6 +880,8 @@ struct usb_wireless_cap_descriptor { /* Ultra Wide Band */
__u8 bReserved; __u8 bReserved;
} __attribute__((packed)); } __attribute__((packed));
#define USB_DT_USB_WIRELESS_CAP_SIZE 11
/* USB 2.0 Extension descriptor */ /* USB 2.0 Extension descriptor */
#define USB_CAP_TYPE_EXT 2 #define USB_CAP_TYPE_EXT 2
@ -1072,6 +1074,7 @@ struct usb_ptm_cap_descriptor {
__u8 bDevCapabilityType; __u8 bDevCapabilityType;
} __attribute__((packed)); } __attribute__((packed));
#define USB_DT_USB_PTM_ID_SIZE 3
/* /*
* The size of the descriptor for the Sublink Speed Attribute Count * The size of the descriptor for the Sublink Speed Attribute Count
* (SSAC) specified in bmAttributes[4:0]. * (SSAC) specified in bmAttributes[4:0].