From: Roberto Sassu <roberto.sassu@huawei.com>
To: Rob Landley <rob@landley.net>, <viro@zeniv.linux.org.uk>
Cc: <linux-security-module@vger.kernel.org>,
<linux-integrity@vger.kernel.org>, <initramfs@vger.kernel.org>,
<linux-api@vger.kernel.org>, <linux-fsdevel@vger.kernel.org>,
<linux-kernel@vger.kernel.org>, <zohar@linux.vnet.ibm.com>,
<silviu.vlasceanu@huawei.com>, <dmitry.kasatkin@huawei.com>,
<takondra@cisco.com>, <kamensky@cisco.com>, <hpa@zytor.com>,
<arnd@arndb.de>, <james.w.mcmechan@gmail.com>
Subject: Re: [PATCH v2 0/3] initramfs: add support for xattrs in the initial ram disk
Date: Fri, 10 May 2019 08:56:18 +0200 [thread overview]
Message-ID: <bf0d02fc-d6ce-ef1d-bb7d-7ca14432c6fd@huawei.com> (raw)
In-Reply-To: <fca8e601-1144-1bb8-c007-518651f624a5@landley.net>
On 5/9/2019 8:34 PM, Rob Landley wrote:
> On 5/9/19 6:24 AM, Roberto Sassu wrote:
>> This patch set aims at solving the following use case: appraise files from
>> the initial ram disk. To do that, IMA checks the signature/hash from the
>> security.ima xattr. Unfortunately, this use case cannot be implemented
>> currently, as the CPIO format does not support xattrs.
>>
>> This proposal consists in marshaling pathnames and xattrs in a file called
>> .xattr-list. They are unmarshaled by the CPIO parser after all files have
>> been extracted.
>
> So it's in-band signalling that has a higher peak memory requirement.
This can be modified. Now I allocate the memory necessary for the path
and all xattrs of a file (max: .xattr-list size - 10 bytes). I could
process each xattr individually (max: 255 + 1 + 65536 bytes).
>> The difference with another proposal
>> (https://lore.kernel.org/patchwork/cover/888071/) is that xattrs can be
>> included in an image without changing the image format, as opposed to
>> defining a new one. As seen from the discussion, if a new format has to be
>> defined, it should fix the issues of the existing format, which requires
>> more time.
>
> So you've explicitly chosen _not_ to address Y2038 while you're there.
Can you be more specific?
Thanks
Roberto
> Rob
>
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HUAWEI TECHNOLOGIES Duesseldorf GmbH, HRB 56063
Managing Director: Bo PENG, Jian LI, Yanli SHI
next prev parent reply other threads:[~2019-05-10 6:56 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-09 11:24 [PATCH v2 0/3] initramfs: add support for xattrs in the initial ram disk Roberto Sassu
2019-05-09 11:24 ` [PATCH v2 1/3] fs: add ksys_lsetxattr() wrapper Roberto Sassu
2019-05-10 21:28 ` Jann Horn
2019-05-09 11:24 ` [PATCH v2 2/3] initramfs: set extended attributes Roberto Sassu
2019-05-09 11:24 ` [PATCH v2 3/3] initramfs: introduce do_readxattrs() Roberto Sassu
2019-05-10 21:33 ` Jann Horn
2019-05-13 13:03 ` Roberto Sassu
2019-05-09 18:34 ` [PATCH v2 0/3] initramfs: add support for xattrs in the initial ram disk Rob Landley
2019-05-10 6:56 ` Roberto Sassu [this message]
2019-05-10 11:49 ` Mimi Zohar
2019-05-10 20:46 ` Rob Landley
2019-05-10 22:38 ` Mimi Zohar
2019-05-11 22:44 ` Andy Lutomirski
2019-05-12 4:04 ` Rob Landley
2019-05-12 4:12 ` Rob Landley
2019-05-12 9:17 ` Dominik Brodowski
2019-05-12 10:18 ` hpa
2019-05-12 15:31 ` Dominik Brodowski
2019-05-13 0:02 ` Mimi Zohar
2019-05-13 0:21 ` hpa
2019-05-13 0:23 ` hpa
2019-05-12 12:52 ` Mimi Zohar
2019-05-12 17:05 ` Rob Landley
2019-05-12 19:43 ` Arvind Sankar
2019-05-13 7:49 ` Roberto Sassu
2019-05-13 9:07 ` Rob Landley
2019-05-13 12:08 ` Mimi Zohar
2019-05-13 12:47 ` Roberto Sassu
2019-05-13 17:20 ` Arvind Sankar
2019-05-13 17:51 ` Arvind Sankar
2019-05-13 17:52 ` Arvind Sankar
2019-05-13 18:36 ` Mimi Zohar
2019-05-13 18:47 ` Arvind Sankar
2019-05-13 22:09 ` Mimi Zohar
2019-05-14 6:06 ` Rob Landley
2019-05-14 14:44 ` Arvind Sankar
2019-05-14 6:06 ` Rob Landley
2019-05-14 11:52 ` Roberto Sassu
2019-05-14 15:12 ` Rob Landley
2019-05-14 15:27 ` Arvind Sankar
2019-05-14 15:57 ` Arvind Sankar
2019-05-14 17:44 ` Roberto Sassu
2019-05-15 1:00 ` Arvind Sankar
2019-05-14 15:19 ` Andy Lutomirski
2019-05-14 16:33 ` Roberto Sassu
2019-05-14 16:58 ` Greg KH
2019-05-14 17:20 ` Roberto Sassu
2019-05-15 0:25 ` Arvind Sankar
2019-05-14 19:18 ` James Bottomley
2019-05-14 23:39 ` Rob Landley
2019-05-14 23:54 ` James Bottomley
2019-05-15 0:52 ` Arvind Sankar
2019-05-15 11:19 ` Roberto Sassu
2019-05-15 16:08 ` Arvind Sankar
2019-05-15 17:06 ` Roberto Sassu
2019-05-16 5:29 ` Arvind Sankar
2019-05-16 11:42 ` Roberto Sassu
2019-05-16 13:31 ` Mimi Zohar
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