From: Christoph Hellwig <hch@infradead.org>
To: Eric Biggers <ebiggers3@gmail.com>
Cc: linux-fscrypt@vger.kernel.org, Theodore Ts'o <tytso@mit.edu>,
linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org,
linux-f2fs-devel@lists.sourceforge.net,
linux-mtd@lists.infradead.org, Eric Biggers <ebiggers@google.com>
Subject: Re: [PATCH 1/3] ext4: require key for truncate(2) of encrypted file
Date: Tue, 13 Jun 2017 23:52:10 -0700 [thread overview]
Message-ID: <20170614065210.GA10411@infradead.org> (raw)
In-Reply-To: <20170613234755.111167-2-ebiggers3@gmail.com>
On Tue, Jun 13, 2017 at 04:47:53PM -0700, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@google.com>
>
> Currently, filesystems allow truncate(2) on an encrypted file without
> the encryption key. However, it's impossible to correctly handle the
> case where the size being truncated to is not a multiple of the
> filesystem block size, because that would require decrypting the final
> block, zeroing the part beyond i_size, then encrypting the block.
>
> As other modifications to encrypted file contents are prohibited without
> the key, just prohibit truncate(2) as well, making it fail with ENOKEY.
What about hole punches? What about fallocate which just adds zeroes
but still changes the content. What about insert or collapse range?
next prev parent reply other threads:[~2017-06-14 6:52 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-13 23:47 [PATCH 0/3] fscrypt: forbid truncate(2) without key Eric Biggers
2017-06-13 23:47 ` [PATCH 1/3] ext4: require key for truncate(2) of encrypted file Eric Biggers
2017-06-14 0:14 ` Andreas Dilger
2017-06-14 3:12 ` Eric Biggers
2017-06-14 4:02 ` Andreas Dilger
2017-06-14 6:52 ` Christoph Hellwig [this message]
2017-06-14 7:03 ` Eric Biggers
2017-06-14 7:06 ` Christoph Hellwig
2017-06-23 23:52 ` Theodore Ts'o
2017-06-13 23:47 ` [PATCH 2/3] f2fs: " Eric Biggers
2017-06-14 12:44 ` [f2fs-dev] " Chao Yu
2017-06-13 23:47 ` [PATCH 3/3] ubifs: " Eric Biggers
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20170614065210.GA10411@infradead.org \
--to=hch@infradead.org \
--cc=ebiggers3@gmail.com \
--cc=ebiggers@google.com \
--cc=linux-ext4@vger.kernel.org \
--cc=linux-f2fs-devel@lists.sourceforge.net \
--cc=linux-fscrypt@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-mtd@lists.infradead.org \
--cc=tytso@mit.edu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).