[3.16.y-ckt extended stable] Patch "ext4: bail out from make_indexed_dir() on first error" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    ext4: bail out from make_indexed_dir() on first error

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt1.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 0f593dc943c6a544de36b97ba625073d0e4a4fab Mon Sep 17 00:00:00 2001
From: Jan Kara <jack at suse.cz>
Date: Thu, 30 Oct 2014 10:53:17 -0400
Subject: ext4: bail out from make_indexed_dir() on first error

commit 6050d47adcadbb53582434d919ed7f038d936712 upstream.

When ext4_handle_dirty_dx_node() or ext4_handle_dirty_dirent_node()
fail, there's really something wrong with the fs and there's no point in
continuing further. Just return error from make_indexed_dir() in that
case. Also initialize frames array so that if we return early due to
error, dx_release() doesn't try to dereference uninitialized memory
(which could happen also due to error in do_split()).

Coverity-id: 741300
Signed-off-by: Jan Kara <jack at suse.cz>
Signed-off-by: Theodore Ts'o <tytso at mit.edu>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 fs/ext4/namei.c | 28 ++++++++++++++++++----------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 50d9225d9e3e..5c0b71c734ea 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1840,31 +1840,39 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
 		hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
 	hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 	ext4fs_dirhash(name, namelen, &hinfo);
+	memset(frames, 0, sizeof(frames));
 	frame = frames;
 	frame->entries = entries;
 	frame->at = entries;
 	frame->bh = bh;
 	bh = bh2;

-	ext4_handle_dirty_dx_node(handle, dir, frame->bh);
-	ext4_handle_dirty_dirent_node(handle, dir, bh);
+	retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
+	if (retval)
+		goto out_frames;
+	retval = ext4_handle_dirty_dirent_node(handle, dir, bh);
+	if (retval)
+		goto out_frames;

 	de = do_split(handle,dir, &bh, frame, &hinfo);
 	if (IS_ERR(de)) {
-		/*
-		 * Even if the block split failed, we have to properly write
-		 * out all the changes we did so far. Otherwise we can end up
-		 * with corrupted filesystem.
-		 */
-		ext4_mark_inode_dirty(handle, dir);
-		dx_release(frames);
-		return PTR_ERR(de);
+		retval = PTR_ERR(de);
+		goto out_frames;
 	}
 	dx_release(frames);

 	retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
 	brelse(bh);
 	return retval;
+out_frames:
+	/*
+	 * Even if the block split failed, we have to properly write
+	 * out all the changes we did so far. Otherwise we can end up
+	 * with corrupted filesystem.
+	 */
+	ext4_mark_inode_dirty(handle, dir);
+	dx_release(frames);
+	return retval;
 }

 /*
--
2.1.0