HID: fix HIDIOCGRDESC memory access in hidraw

Fix bogus copying of data into userspace when HIDIOCGRDESC is issued.
HID-transport layer makes sure that dev->hid->rdesc is not larger than
HID_MAX_DESCRIPTOR_SIZE.

Noticed-by: Al Viro <viro@ftp.linux.org.uk>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Jiri Kosina 2007-10-15 15:17:41 +02:00 committed by Linus Torvalds
parent 23fd50450a
commit 57d292bd7e
3 changed files with 24 additions and 14 deletions

View file

@ -229,9 +229,15 @@ static int hidraw_ioctl(struct inode *inode, struct file *file, unsigned int cmd
if (get_user(len, (int __user *)arg))
return -EFAULT;
if (copy_to_user(*((__u8 **)(user_arg +
sizeof(__u32))),
dev->hid->rdesc, len))
if (len > HID_MAX_DESCRIPTOR_SIZE - 1)
return -EINVAL;
if (copy_to_user(user_arg + offsetof(
struct hidraw_report_descriptor,
value[0]),
dev->hid->rdesc,
min(dev->hid->rsize, len)))
return -EFAULT;
return 0;
}

View file

@ -29,13 +29,6 @@
* Vojtech Pavlik, Simunkova 1594, Prague 8, 182 00 Czech Republic
*/
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/timer.h>
#include <linux/workqueue.h>
#include <linux/input.h>
/*
* USB HID (Human Interface Device) interface class code
*/
@ -69,6 +62,17 @@
#define HID_DT_REPORT (USB_TYPE_CLASS | 0x02)
#define HID_DT_PHYSICAL (USB_TYPE_CLASS | 0x03)
#define HID_MAX_DESCRIPTOR_SIZE 4096
#ifdef __KERNEL__
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/timer.h>
#include <linux/workqueue.h>
#include <linux/input.h>
/*
* We parse each description item into this structure. Short items data
* values are expanded to 32-bit signed int, long items contain a pointer
@ -311,7 +315,6 @@ struct hid_global {
* This is the local environment. It is persistent up the next main-item.
*/
#define HID_MAX_DESCRIPTOR_SIZE 4096
#define HID_MAX_USAGES 8192
#define HID_DEFAULT_NUM_COLLECTIONS 16
@ -560,4 +563,5 @@ static inline int hid_ff_init(struct hid_device *hid) { return -1; }
#define err_hid(format, arg...) printk(KERN_ERR "%s: " format "\n" , \
__FILE__ , ## arg)
#endif
#endif

View file

@ -15,9 +15,11 @@
* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <linux/hid.h>
struct hidraw_report_descriptor {
__u32 size;
__u8 *value;
__u8 value[HID_MAX_DESCRIPTOR_SIZE];
};
struct hidraw_devinfo {
@ -40,8 +42,6 @@ struct hidraw_devinfo {
/* kernel-only API declarations */
#ifdef __KERNEL__
#include <linux/hid.h>
struct hidraw {
unsigned int minor;
int exist;