linux-kernel - [PATCH 4.9 25/29] btrfs: fixup error handling in fixup_inode_link

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Message-Id: <20210608175928.637405503@linuxfoundation.org>
Date:   Tue,  8 Jun 2021 20:27:19 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Josef Bacik <josef@...icpanda.com>,
        David Sterba <dsterba@...e.com>
Subject: [PATCH 4.9 25/29] btrfs: fixup error handling in fixup_inode_link_counts

From: Josef Bacik <josef@...icpanda.com>

commit 011b28acf940eb61c000059dd9e2cfcbf52ed96b upstream.

This function has the following pattern

	while (1) {
		ret = whatever();
		if (ret)
			goto out;
	}
	ret = 0
out:
	return ret;

However several places in this while loop we simply break; when there's
a problem, thus clearing the return value, and in one case we do a
return -EIO, and leak the memory for the path.

Fix this by re-arranging the loop to deal with ret == 1 coming from
btrfs_search_slot, and then simply delete the

	ret = 0;
out:

bit so everybody can break if there is an error, which will allow for
proper error handling to occur.

CC: stable@...r.kernel.org # 4.4+
Signed-off-by: Josef Bacik <josef@...icpanda.com>
Reviewed-by: David Sterba <dsterba@...e.com>
Signed-off-by: David Sterba <dsterba@...e.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 fs/btrfs/tree-log.c |   13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -1529,6 +1529,7 @@ static noinline int fixup_inode_link_cou
 			break;
 
 		if (ret == 1) {
+			ret = 0;
 			if (path->slots[0] == 0)
 				break;
 			path->slots[0]--;
@@ -1541,17 +1542,19 @@ static noinline int fixup_inode_link_cou
 
 		ret = btrfs_del_item(trans, root, path);
 		if (ret)
-			goto out;
+			break;
 
 		btrfs_release_path(path);
 		inode = read_one_inode(root, key.offset);
-		if (!inode)
-			return -EIO;
+		if (!inode) {
+			ret = -EIO;
+			break;
+		}
 
 		ret = fixup_inode_link_count(trans, root, inode);
 		iput(inode);
 		if (ret)
-			goto out;
+			break;
 
 		/*
 		 * fixup on a directory may create new entries,
@@ -1560,8 +1563,6 @@ static noinline int fixup_inode_link_cou
 		 */
 		key.offset = (u64)-1;
 	}
-	ret = 0;
-out:
 	btrfs_release_path(path);
 	return ret;
 }