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
| ||
|
Message-ID: <20170602175935.GB5626@birch.djwong.org> Date: Fri, 2 Jun 2017 10:59:35 -0700 From: "Darrick J. Wong" <darrick.wong@...cle.com> To: Tahsin Erdogan <tahsin@...gle.com> Cc: Jan Kara <jack@...e.com>, "Theodore Ts'o" <tytso@....edu>, Andreas Dilger <adilger.kernel@...ger.ca>, Dave Kleikamp <shaggy@...nel.org>, Alexander Viro <viro@...iv.linux.org.uk>, Mark Fasheh <mfasheh@...sity.com>, Joel Becker <jlbec@...lplan.org>, Jens Axboe <axboe@...com>, Deepa Dinamani <deepa.kernel@...il.com>, Mike Christie <mchristi@...hat.com>, Fabian Frederick <fabf@...net.be>, linux-ext4@...r.kernel.org, linux-kernel@...r.kernel.org, jfs-discussion@...ts.sourceforge.net, linux-fsdevel@...r.kernel.org, ocfs2-devel@....oracle.com, reiserfs-devel@...r.kernel.org Subject: Re: [PATCH v2 27/28] ext4: xattr inode deduplication On Fri, Jun 02, 2017 at 05:46:22AM -0700, Tahsin Erdogan wrote: > > Hmm... normally we'd supply sbi->s_csum_seed as the second argument so > > that the metadata checksum value also has the fs uuid stamped into it. > > I have thought about using sbi->s_csum_seed and was a little hesitant > because it involves adding more complexity to e2fsprogs to handle > cases like changing uuid or turning off metadata_csum. After thinking > more about this, I think it is doable. e2fsprogs already has code to walk the fs to rewrite/remove checksums, so it shouldn't be too much effort to tap into that to rewrite the ea_info hash. > > Even if you dismiss that, we usually follow the convention of > > initializing the crc32c calculation with (~0U), not (0U), to strengthen > > crc32c's ability to detect zeroes being injected at the start of the > > stream. > > Agreed, using ~0 is definitely better than 0. --D
Powered by blists - more mailing lists