linux-kernel - Re: [f2fs-dev] [PATCH AUTOSEL 5.10 10/31] f2fs: Handle casefolding with Encryption

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]

Date:   Wed, 30 Dec 2020 10:01:56 -0800
From:   Eric Biggers <ebiggers@...nel.org>
To:     Sasha Levin <sashal@...nel.org>
Cc:     linux-kernel@...r.kernel.org, stable@...r.kernel.org,
        Jaegeuk Kim <jaegeuk@...nel.org>,
        linux-f2fs-devel@...ts.sourceforge.net,
        Daniel Rosenberg <drosen@...gle.com>
Subject: Re: [f2fs-dev] [PATCH AUTOSEL 5.10 10/31] f2fs: Handle casefolding
 with Encryption

On Wed, Dec 30, 2020 at 08:02:52AM -0500, Sasha Levin wrote:
> From: Daniel Rosenberg <drosen@...gle.com>
> 
> [ Upstream commit 7ad08a58bf67594057362e45cbddd3e27e53e557 ]
> 
> Expand f2fs's casefolding support to include encrypted directories.  To
> index casefolded+encrypted directories, we use the SipHash of the
> casefolded name, keyed by a key derived from the directory's fscrypt
> master key.  This ensures that the dirhash doesn't leak information
> about the plaintext filenames.
> 
> Encryption keys are unavailable during roll-forward recovery, so we
> can't compute the dirhash when recovering a new dentry in an encrypted +
> casefolded directory.  To avoid having to force a checkpoint when a new
> file is fsync'ed, store the dirhash on-disk appended to i_name.
> 
> This patch incorporates work by Eric Biggers <ebiggers@...gle.com>
> and Jaegeuk Kim <jaegeuk@...nel.org>.
> 
> Co-developed-by: Eric Biggers <ebiggers@...gle.com>
> Signed-off-by: Eric Biggers <ebiggers@...gle.com>
> Signed-off-by: Daniel Rosenberg <drosen@...gle.com>
> Reviewed-by: Eric Biggers <ebiggers@...gle.com>
> Signed-off-by: Jaegeuk Kim <jaegeuk@...nel.org>
> Signed-off-by: Sasha Levin <sashal@...nel.org>

Please don't backport this to the LTS kernels.  This is a new feature, not a
fix, and you missed prerequisite patches...

- Eric