fbdev: sbuslib: integer overflow in sbusfb_ioctl_helper()

The "index + count" addition can overflow.  Both come directly from the
user.  This bug leads to an information leak.

Signed-off-by: Dan Carpenter <[email protected]>
Cc: Peter Malone <[email protected]>
Cc: Philippe Ombredanne <[email protected]>
Cc: Mathieu Malaterre <[email protected]>
Signed-off-by: Bartlomiej Zolnierkiewicz <[email protected]>
This commit is contained in:
Dan Carpenter 2018-10-08 12:57:36 +02:00 • committed by Bartlomiej Zolnierkiewicz
commit e5017716ad

View file

@ -171,7 +171,7 @@ int sbusfb_ioctl_helper(unsigned long cmd, unsigned long arg,
get_user(ublue, &c->blue))
return -EFAULT;
if (index + count > cmap->len)
if (index > cmap->len || count > cmap->len - index)
return -EINVAL;
for (i = 0; i < count; i++) {