ext4: fix possible leak of sbi->s_group_desc_leak in error path

Fixes: bfe0a5f4 ("ext4: add more mount time checks of the superblock")
Reported-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org # 4.18

fs/ext4/super.c

@@ -4075,6 +4075,14 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 	sbi->s_groups_count = blocks_count;
 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
+	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
+	    le32_to_cpu(es->s_inodes_count)) {
+		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
+			 le32_to_cpu(es->s_inodes_count),
+			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
+		ret = -EINVAL;
+		goto failed_mount;
+	}
 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
 		   EXT4_DESC_PER_BLOCK(sb);
 	if (ext4_has_feature_meta_bg(sb)) {
@@ -4094,14 +4102,6 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		ret = -ENOMEM;
 		goto failed_mount;
 	}
-	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
-	    le32_to_cpu(es->s_inodes_count)) {
-		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
-			 le32_to_cpu(es->s_inodes_count),
-			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
-		ret = -EINVAL;
-		goto failed_mount;
-	}
 
 	bgl_lock_init(sbi->s_blockgroup_lock);