1 files changed, 97 insertions, 41 deletions

diff --git a/drivers/input/joydev.c b/drivers/input/joydev.c
index 0e12f89276a3..901b2525993e 100644
--- a/drivers/input/joydev.c
+++ b/drivers/input/joydev.c
@@ -452,12 +452,85 @@ static unsigned int joydev_poll(struct file *file, poll_table *wait)
 		(joydev->exist ?  0 : (POLLHUP | POLLERR));
 }
 
+static int joydev_handle_JSIOCSAXMAP(struct joydev *joydev,
+				     void __user *argp, size_t len)
+{
+	__u8 *abspam;
+	int i;
+	int retval = 0;
+
+	len = min(len, sizeof(joydev->abspam));
+
+	/* Validate the map. */
+	abspam = kmalloc(len, GFP_KERNEL);
+	if (!abspam)
+		return -ENOMEM;
+
+	if (copy_from_user(abspam, argp, len)) {
+		retval = -EFAULT;
+		goto out;
+	}
+
+	for (i = 0; i < joydev->nabs; i++) {
+		if (abspam[i] > ABS_MAX) {
+			retval = -EINVAL;
+			goto out;
+		}
+	}
+
+	memcpy(joydev->abspam, abspam, len);
+
+ out:
+	kfree(abspam);
+	return retval;
+}
+
+static int joydev_handle_JSIOCSBTNMAP(struct joydev *joydev,
+				      void __user *argp, size_t len)
+{
+	__u16 *keypam;
+	int i;
+	int retval = 0;
+
+	len = min(len, sizeof(joydev->keypam));
+
+	/* Validate the map. */
+	keypam = kmalloc(len, GFP_KERNEL);
+	if (!keypam)
+		return -ENOMEM;
+
+	if (copy_from_user(keypam, argp, len)) {
+		retval = -EFAULT;
+		goto out;
+	}
+
+	for (i = 0; i < joydev->nkey; i++) {
+		if (keypam[i] > KEY_MAX || keypam[i] < BTN_MISC) {
+			retval = -EINVAL;
+			goto out;
+		}
+	}
+
+	memcpy(joydev->keypam, keypam, len);
+
+	for (i = 0; i < joydev->nkey; i++)
+		joydev->keymap[keypam[i] - BTN_MISC] = i;
+
+ out:
+	kfree(keypam);
+	return retval;
+}
+
+
 static int joydev_ioctl_common(struct joydev *joydev,
 				unsigned int cmd, void __user *argp)
 {
 	struct input_dev *dev = joydev->handle.dev;
+	size_t len;
 	int i, j;
+	const char *name;
 
+	/* Process fixed-sized commands. */
 	switch (cmd) {
 
 	case JS_SET_CAL:
@@ -499,55 +572,38 @@ static int joydev_ioctl_common(struct joydev *joydev,
 		return copy_to_user(argp, joydev->corr,
 			sizeof(joydev->corr[0]) * joydev->nabs) ? -EFAULT : 0;
 
-	case JSIOCSAXMAP:
-		if (copy_from_user(joydev->abspam, argp,
-				   sizeof(__u8) * (ABS_MAX + 1)))
-			return -EFAULT;
+	}
 
-		for (i = 0; i < joydev->nabs; i++) {
-			if (joydev->abspam[i] > ABS_MAX)
-				return -EINVAL;
-			joydev->absmap[joydev->abspam[i]] = i;
-		}
-		return 0;
+	/*
+	 * Process variable-sized commands (the axis and button map commands
+	 * are considered variable-sized to decouple them from the values of
+	 * ABS_MAX and KEY_MAX).
+	 */
+	switch (cmd & ~IOCSIZE_MASK) {
 
-	case JSIOCGAXMAP:
-		return copy_to_user(argp, joydev->abspam,
-			sizeof(__u8) * (ABS_MAX + 1)) ? -EFAULT : 0;
+	case (JSIOCSAXMAP & ~IOCSIZE_MASK):
+		return joydev_handle_JSIOCSAXMAP(joydev, argp, _IOC_SIZE(cmd));
 
-	case JSIOCSBTNMAP:
-		if (copy_from_user(joydev->keypam, argp,
-				   sizeof(__u16) * (KEY_MAX - BTN_MISC + 1)))
-			return -EFAULT;
+	case (JSIOCGAXMAP & ~IOCSIZE_MASK):
+		len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->abspam));
+		return copy_to_user(argp, joydev->abspam, len) ? -EFAULT : len;
 
-		for (i = 0; i < joydev->nkey; i++) {
-			if (joydev->keypam[i] > KEY_MAX ||
-			    joydev->keypam[i] < BTN_MISC)
-				return -EINVAL;
-			joydev->keymap[joydev->keypam[i] - BTN_MISC] = i;
-		}
+	case (JSIOCSBTNMAP & ~IOCSIZE_MASK):
+		return joydev_handle_JSIOCSBTNMAP(joydev, argp, _IOC_SIZE(cmd));
 
-		return 0;
+	case (JSIOCGBTNMAP & ~IOCSIZE_MASK):
+		len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->keypam));
+		return copy_to_user(argp, joydev->keypam, len) ? -EFAULT : len;
 
-	case JSIOCGBTNMAP:
-		return copy_to_user(argp, joydev->keypam,
-			sizeof(__u16) * (KEY_MAX - BTN_MISC + 1)) ? -EFAULT : 0;
+	case JSIOCGNAME(0):
+		name = dev->name;
+		if (!name)
+			return 0;
 
-	default:
-		if ((cmd & ~IOCSIZE_MASK) == JSIOCGNAME(0)) {
-			int len;
-			const char *name = dev_name(&dev->dev);
-
-			if (!name)
-				return 0;
-			len = strlen(name) + 1;
-			if (len > _IOC_SIZE(cmd))
-				len = _IOC_SIZE(cmd);
-			if (copy_to_user(argp, name, len))
-				return -EFAULT;
-			return len;
-		}
+		len = min_t(size_t, _IOC_SIZE(cmd), strlen(name) + 1);
+		return copy_to_user(argp, name, len) ? -EFAULT : len;
 	}
+
 	return -EINVAL;
 }