xfs: Plug memory leak in xfs_attrmulti_attr_set

When setting attributes via XFS_IOC_ATTRMULTI_BY_HANDLE, the user-space
buffer is copied into a new kernel-space buffer via memdup_user; that
buffer then isn't freed.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

fs/xfs/xfs_ioctl.c

@@ -482,6 +482,7 @@ xfs_attrmulti_attr_set(
 	__uint32_t		flags)
 {
 	unsigned char		*kbuf;
+	int			error;
 
 	if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
 		return -EPERM;
@@ -492,7 +493,9 @@ xfs_attrmulti_attr_set(
 	if (IS_ERR(kbuf))
 		return PTR_ERR(kbuf);
 
-	return xfs_attr_set(XFS_I(inode), name, kbuf, len, flags);
+	error = xfs_attr_set(XFS_I(inode), name, kbuf, len, flags);
+	kfree(kbuf);
+	return error;
 }
 
 int