linux-kernel - Re: [PATCH 028/270] ext4: remove erroneous ext4_superblock_csum_set() in update

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1353982939.4266.38.camel@deadeye.wl.decadent.org.uk>
Date:	Tue, 27 Nov 2012 02:22:19 +0000
From:	Ben Hutchings <ben@...adent.org.uk>
To:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:	linux-kernel@...r.kernel.org, stable@...r.kernel.org,
	kernel-team@...ts.ubuntu.com, Tao Ma <boyu.mt@...bao.com>,
	Theodore Ts'o <tytso@....edu>,
	Herton Ronaldo Krzesinski <herton.krzesinski@...onical.com>
Subject: Re: [PATCH 028/270] ext4: remove erroneous
 ext4_superblock_csum_set() in update_backups()

On Mon, 2012-11-26 at 14:55 -0200, Herton Ronaldo Krzesinski wrote:
> 3.5.7u1 -stable review patch.  If anyone has any objections, please let me know.
> 
> ------------------
> 
> From: Tao Ma <boyu.mt@...bao.com>
> 
> commit bef53b01faeb791e27605cba1a71ba21364cb23e upstream.
> 
> The update_backups() function is used to backup all the metadata
> blocks, so we should not take it for granted that 'data' is pointed to
> a super block and use ext4_superblock_csum_set to calculate the
> checksum there.  In case where the data is a group descriptor block,
> it will corrupt the last group descriptor, and then e2fsck will
> complain about it it.
> 
> As all the metadata checksums should already be OK when we do the
> backup, remove the wrong ext4_superblock_csum_set and it should be
> just fine.
> 
> Reported-by: "Theodore Ts'o" <tytso@....edu>
> Signed-off-by: Tao Ma <boyu.mt@...bao.com>
> Signed-off-by: "Theodore Ts'o" <tytso@....edu>
> [ herton: adjust context ]
> Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@...onical.com>

This should also be applicable to 3.6.

Ben.

> ---
>  fs/ext4/resize.c |    2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
> index b0bdd10..dc1affc 100644
> --- a/fs/ext4/resize.c
> +++ b/fs/ext4/resize.c
> @@ -979,8 +979,6 @@ static void update_backups(struct super_block *sb,
>  		goto exit_err;
>  	}
>  
> -	ext4_superblock_csum_set(sb, (struct ext4_super_block *)data);
> -
>  	while ((group = ext4_list_backups(sb, &three, &five, &seven)) < last) {
>  		struct buffer_head *bh;
>  

-- 
Ben Hutchings
Never attribute to conspiracy what can adequately be explained by stupidity.

Download attachment "signature.asc" of type "application/pgp-signature" (829 bytes)