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

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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
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28
drivers/usb/core/config.c
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 */
int usb_get_bos_descriptor(struct usb_device *dev)
{
struct device *ddev = &dev->dev;
struct usb_bos_descriptor *bos;
struct usb_dev_cap_header *cap;
struct usb_ssp_cap_descriptor *ssp_cap;
unsigned char *buffer;
int length, total_len, num, i;
int length, total_len, num, i, ssac;
__u8 cap_type;
int ret;
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;
break;
}
cap_type = cap->bDevCapabilityType;
length = cap->bLength;
if (bos_desc_len[cap_type] && length < bos_desc_len[cap_type]) {
dev->bos->desc->bNumDeviceCaps = i;
break;
}
total_len -= length;
if (cap->bDescriptorType != USB_DT_DEVICE_CAPABILITY) {
@ -973,7 +990,7 @@ int usb_get_bos_descriptor(struct usb_device *dev)
continue;
}
switch (cap->bDevCapabilityType) {
switch (cap_type) {
case USB_CAP_TYPE_WIRELESS_USB:
/* Wireless USB cap descriptor is handled by wusb */
break;
@ -986,8 +1003,11 @@ int usb_get_bos_descriptor(struct usb_device *dev)
(struct usb_ss_cap_descriptor *)buffer;
break;
case USB_SSP_CAP_TYPE:
dev->bos->ssp_cap =
(struct usb_ssp_cap_descriptor *)buffer;
ssp_cap = (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;
case CONTAINER_ID_TYPE:
dev->bos->ss_id =

3
include/uapi/linux/usb/ch9.h
View file

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