diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index 338666a97fff..29b27d769860 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -169,15 +169,19 @@ static int gfs2_check_sb(struct gfs2_sbd *sdp, int silent)
 		return -EINVAL;
 	}
 
-	/*  If format numbers match exactly, we're done.  */
+	if (sb->sb_fs_format != GFS2_FORMAT_FS ||
+	    sb->sb_multihost_format != GFS2_FORMAT_MULTI) {
+		fs_warn(sdp, "Unknown on-disk format, unable to mount\n");
+		return -EINVAL;
+	}
 
-	if (sb->sb_fs_format == GFS2_FORMAT_FS &&
-	    sb->sb_multihost_format == GFS2_FORMAT_MULTI)
-		return 0;
+	if (sb->sb_bsize < 512 || sb->sb_bsize > PAGE_SIZE ||
+	    (sb->sb_bsize & (sb->sb_bsize - 1))) {
+		pr_warn("Invalid superblock size\n");
+		return -EINVAL;
+	}
 
-	fs_warn(sdp, "Unknown on-disk format, unable to mount\n");
-
-	return -EINVAL;
+	return 0;
 }
 
 static void end_bio_io_page(struct bio *bio)