linux-ext4 - Re: [PATCH 01/25] e2fsck/debugfs: fix descriptor block size handling errors with journal

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: <20140911164302.GI26178@thunk.org>
Date:	Thu, 11 Sep 2014 12:43:02 -0400
From:	Theodore Ts'o <tytso@....edu>
To:	"Darrick J. Wong" <darrick.wong@...cle.com>
Cc:	linux-ext4@...r.kernel.org, TR Reardon <thomas_reardon@...mail.com>
Subject: Re: [PATCH 01/25] e2fsck/debugfs: fix descriptor block size handling
 errors with journal_csum

On Mon, Sep 08, 2014 at 04:11:43PM -0700, Darrick J. Wong wrote:
> It turns out that there are some serious problems with the on-disk
> format of journal checksum v2.  The foremost is that the function to
> calculate descriptor tag size returns sizes that are too big.  This
> causes alignment issues on some architectures and is compounded by the
> fact that some parts of jbd2 use the structure size (incorrectly) to
> determine the presence of a 64bit journal instead of checking the
> feature flags.  These errors regrettably lead to the journal
> corruption reported by Mr. Reardon.
> 
> Therefore, introduce journal checksum v3, which enlarges the
> descriptor block tag format to allow for full 32-bit checksums of
> journal blocks, fix the journal tag function to return the correct
> sizes, and fix the jbd2 recovery code to use feature flags to
> determine 64bitness.
> 
> Add a few function helpers so we don't have to open-code quite so
> many pieces.
> 
> Switching to a 16-byte block size was found to increase journal size
> overhead by a maximum of 0.1%, to convert a 32-bit journal with no
> checksumming to a 32-bit journal with checksum v3 enabled.
> 
> Signed-off-by: Darrick J. Wong <darrick.wong@...cle.com>
> Reported-by: TR Reardon <thomas_reardon@...mail.com>

Applied, thanks.

					- Ted
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html