From: Chao Yu <chao@kernel.org>
To: Eric Biggers <ebiggers3@gmail.com>, linux-fscrypt@vger.kernel.org
Cc: Theodore Ts'o <tytso@mit.edu>, Eric Biggers <ebiggers@google.com>,
linux-f2fs-devel@lists.sourceforge.net,
linux-mtd@lists.infradead.org, linux-fsdevel@vger.kernel.org,
linux-ext4@vger.kernel.org
Subject: Re: [f2fs-dev] [PATCH 2/3] f2fs: require key for truncate(2) of encrypted file
Date: Wed, 14 Jun 2017 20:44:19 +0800 [thread overview]
Message-ID: <e558657c-d383-4528-9be0-8c2d1ab8344c@kernel.org> (raw)
In-Reply-To: <20170613234755.111167-3-ebiggers3@gmail.com>
On 2017/6/14 7:47, 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.
>
> Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Chao Yu <yuchao0@huawei.com>
Thanks,
next prev parent reply other threads:[~2017-06-14 12:44 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
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 ` Chao Yu [this message]
2017-06-13 23:47 ` [PATCH 3/3] ubifs: " Eric Biggers
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