ext4: fix error code return to user-space in ext4_get_branch()

commit 26d75a1 upstream.

If a block is out of range in ext4_get_branch(), -ENOMEM will be returned
to user-space.  Obviously, this error code isn't really useful.  This
patch fixes it by making sure the right error code (-EFSCORRUPTED) is
propagated to user-space.  EUCLEAN is more informative than ENOMEM.

Signed-off-by: Luís Henriques <lhenriques@suse.de>
Link: https://lore.kernel.org/r/20221109181445.17843-1-lhenriques@suse.de
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/ext4/indirect.c

@@ -148,6 +148,7 @@ static Indirect *ext4_get_branch(struct inode *inode, int depth,
 	struct super_block *sb = inode->i_sb;
 	Indirect *p = chain;
 	struct buffer_head *bh;
+	unsigned int key;
 	int ret = -EIO;
 
 	*err = 0;
@@ -156,7 +157,13 @@ static Indirect *ext4_get_branch(struct inode *inode, int depth,
 	if (!p->key)
 		goto no_block;
 	while (--depth) {
-		bh = sb_getblk(sb, le32_to_cpu(p->key));
+		key = le32_to_cpu(p->key);
+		if (key > ext4_blocks_count(EXT4_SB(sb)->s_es)) {
+			/* the block was out of range */
+			ret = -EFSCORRUPTED;
+			goto failure;
+		}
+		bh = sb_getblk(sb, key);
 		if (unlikely(!bh)) {
 			ret = -ENOMEM;
 			goto failure;