1 files changed, 23 insertions, 21 deletions

diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c
index dd9f1bebb5a3..b7c816f39404 100644
--- a/fs/autofs4/dev-ioctl.c
+++ b/fs/autofs4/dev-ioctl.c
@@ -93,17 +93,17 @@ static int check_dev_ioctl_version(int cmd, struct autofs_dev_ioctl *param)
  * at the end of the struct.
  */
 static struct autofs_dev_ioctl *
-		copy_dev_ioctl(struct autofs_dev_ioctl __user *in)
+copy_dev_ioctl(struct autofs_dev_ioctl __user *in)
 {
 	struct autofs_dev_ioctl tmp, *res;
 
-	if (copy_from_user(&tmp, in, sizeof(tmp)))
+	if (copy_from_user(&tmp, in, AUTOFS_DEV_IOCTL_SIZE))
 		return ERR_PTR(-EFAULT);
 
-	if (tmp.size < sizeof(tmp))
+	if (tmp.size < AUTOFS_DEV_IOCTL_SIZE)
 		return ERR_PTR(-EINVAL);
 
-	if (tmp.size > (PATH_MAX + sizeof(tmp)))
+	if (tmp.size > AUTOFS_DEV_IOCTL_SIZE + PATH_MAX)
 		return ERR_PTR(-ENAMETOOLONG);
 
 	res = memdup_user(in, tmp.size);
@@ -133,8 +133,8 @@ static int validate_dev_ioctl(int cmd, struct autofs_dev_ioctl *param)
 		goto out;
 	}
 
-	if (param->size > sizeof(*param)) {
-		err = invalid_str(param->path, param->size - sizeof(*param));
+	if (param->size > AUTOFS_DEV_IOCTL_SIZE) {
+		err = invalid_str(param->path, param->size - AUTOFS_DEV_IOCTL_SIZE);
 		if (err) {
 			pr_warn(
 			  "path string terminator missing for cmd(0x%08x)\n",
@@ -258,11 +258,6 @@ static int autofs_dev_ioctl_open_mountpoint(const char *name, dev_t devid)
 		if (err)
 			goto out;
 
-		/*
-		 * Find autofs super block that has the device number
-		 * corresponding to the autofs fs we want to open.
-		 */
-
 		filp = dentry_open(&path, O_RDONLY, current_cred());
 		path_put(&path);
 		if (IS_ERR(filp)) {
@@ -451,7 +446,7 @@ static int autofs_dev_ioctl_requester(struct file *fp,
 	dev_t devid;
 	int err = -ENOENT;
 
-	if (param->size <= sizeof(*param)) {
+	if (param->size <= AUTOFS_DEV_IOCTL_SIZE) {
 		err = -EINVAL;
 		goto out;
 	}
@@ -539,7 +534,7 @@ static int autofs_dev_ioctl_ismountpoint(struct file *fp,
 	unsigned int devid, magic;
 	int err = -ENOENT;
 
-	if (param->size <= sizeof(*param)) {
+	if (param->size <= AUTOFS_DEV_IOCTL_SIZE) {
 		err = -EINVAL;
 		goto out;
 	}
@@ -628,10 +623,6 @@ static int _autofs_dev_ioctl(unsigned int command,
 	ioctl_fn fn = NULL;
 	int err = 0;
 
-	/* only root can play with this */
-	if (!capable(CAP_SYS_ADMIN))
-		return -EPERM;
-
 	cmd_first = _IOC_NR(AUTOFS_DEV_IOCTL_IOC_FIRST);
 	cmd = _IOC_NR(command);
 
@@ -640,6 +631,14 @@ static int _autofs_dev_ioctl(unsigned int command,
 		return -ENOTTY;
 	}
 
+	/* Only root can use ioctls other than AUTOFS_DEV_IOCTL_VERSION_CMD
+	 * and AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD
+	 */
+	if (cmd != AUTOFS_DEV_IOCTL_VERSION_CMD &&
+	    cmd != AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD &&
+	    !capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
 	/* Copy the parameters into kernel space. */
 	param = copy_dev_ioctl(user);
 	if (IS_ERR(param))
@@ -706,7 +705,8 @@ out:
 	return err;
 }
 
-static long autofs_dev_ioctl(struct file *file, uint command, ulong u)
+static long autofs_dev_ioctl(struct file *file, unsigned int command,
+			     unsigned long u)
 {
 	int err;
 
@@ -715,9 +715,10 @@ static long autofs_dev_ioctl(struct file *file, uint command, ulong u)
 }
 
 #ifdef CONFIG_COMPAT
-static long autofs_dev_ioctl_compat(struct file *file, uint command, ulong u)
+static long autofs_dev_ioctl_compat(struct file *file, unsigned int command,
+				    unsigned long u)
 {
-	return (long) autofs_dev_ioctl(file, command, (ulong) compat_ptr(u));
+	return autofs_dev_ioctl(file, command, (unsigned long) compat_ptr(u));
 }
 #else
 #define autofs_dev_ioctl_compat NULL
@@ -733,7 +734,8 @@ static const struct file_operations _dev_ioctl_fops = {
 static struct miscdevice _autofs_dev_ioctl_misc = {
 	.minor		= AUTOFS_MINOR,
 	.name		= AUTOFS_DEVICE_NAME,
-	.fops		= &_dev_ioctl_fops
+	.fops		= &_dev_ioctl_fops,
+	.mode           = 0644,
 };
 
 MODULE_ALIAS_MISCDEV(AUTOFS_MINOR);