From: Paul Moore <paul@paul-moore.com>
To: David Howells <dhowells@redhat.com>
Cc: linux-unionfs@vger.kernel.org, selinux@tycho.nsa.gov,
linux-fsdevel@vger.kernel.org,
linux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/7] Security: Provide copy-up security hooks for unioned files
Date: Fri, 07 Nov 2014 16:22:58 -0500 [thread overview]
Message-ID: <2455443.WUExuKDC0I@sifl> (raw)
In-Reply-To: <20141105154228.2555.55814.stgit@warthog.procyon.org.uk>
On Wednesday, November 05, 2014 03:42:28 PM David Howells wrote:
> Provide two new security hooks for use with security files that are used
> when a file is copied up between layers:
>
> (1) security_inode_copy_up(). This is called so that the security label on
> the destination file can be set appropriately.
>
> (2) security_inode_copy_up_xattr(). This is called so that each xattr
> being copied up can be vetted - including modification and discard.
This didn't occur to me earlier, but we may want to pick a different phrase to
use instead of "copy_up" as that has a special meaning for some security/MLS
folks (although strangely enough, I suspect most of these copy-on-write
operations will be "copy up" in the MLS sense of the word).
How about "security_inode_copy_overlay" or something like that?
> + * @inode_copy_up_xattr:
> + * Filter/modify the xattrs being copied up when a unioned file is
> ...copied
> + * up from a lower layer to the union/overlay layer.
> + * @src indicates the file that is being copied up.
> + * @dst indicates the file that has being created by the copy up.
> + * @name indicates the name of the xattr.
> + * @value, *@size indicate the payload of the xattr.
> + * Returns 0 to accept the xattr, 1 to discard the xattr or a negative
> + * error code to abort the copy up. The xattr buffer must be at least
> + * XATTR_SIZE_MAX in capacity and the contents may be modified and
> ....*@size
> + * changed appropriately.
Just so I'm clean, if the LSM wanted to modify the xattr it would modify
@value/@size and return 0?
--
paul moore
www.paul-moore.com
WARNING: multiple messages have this Message-ID (diff)
From: Paul Moore <paul@paul-moore.com>
To: David Howells <dhowells@redhat.com>
Cc: linux-fsdevel@vger.kernel.org,
linux-security-module@vger.kernel.org,
linux-unionfs@vger.kernel.org, selinux@tycho.nsa.gov,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/7] Security: Provide copy-up security hooks for unioned files
Date: Fri, 07 Nov 2014 16:22:58 -0500 [thread overview]
Message-ID: <2455443.WUExuKDC0I@sifl> (raw)
In-Reply-To: <20141105154228.2555.55814.stgit@warthog.procyon.org.uk>
On Wednesday, November 05, 2014 03:42:28 PM David Howells wrote:
> Provide two new security hooks for use with security files that are used
> when a file is copied up between layers:
>
> (1) security_inode_copy_up(). This is called so that the security label on
> the destination file can be set appropriately.
>
> (2) security_inode_copy_up_xattr(). This is called so that each xattr
> being copied up can be vetted - including modification and discard.
This didn't occur to me earlier, but we may want to pick a different phrase to
use instead of "copy_up" as that has a special meaning for some security/MLS
folks (although strangely enough, I suspect most of these copy-on-write
operations will be "copy up" in the MLS sense of the word).
How about "security_inode_copy_overlay" or something like that?
> + * @inode_copy_up_xattr:
> + * Filter/modify the xattrs being copied up when a unioned file is
> ...copied
> + * up from a lower layer to the union/overlay layer.
> + * @src indicates the file that is being copied up.
> + * @dst indicates the file that has being created by the copy up.
> + * @name indicates the name of the xattr.
> + * @value, *@size indicate the payload of the xattr.
> + * Returns 0 to accept the xattr, 1 to discard the xattr or a negative
> + * error code to abort the copy up. The xattr buffer must be at least
> + * XATTR_SIZE_MAX in capacity and the contents may be modified and
> ....*@size
> + * changed appropriately.
Just so I'm clean, if the LSM wanted to modify the xattr it would modify
@value/@size and return 0?
--
paul moore
www.paul-moore.com
next prev parent reply other threads:[~2014-11-07 21:23 UTC|newest]
Thread overview: 89+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-05 15:42 [PATCH 0/7] Security: Provide unioned file support David Howells
2014-11-05 15:42 ` [PATCH 1/7] Security: Provide copy-up security hooks for unioned files David Howells
2014-11-06 17:46 ` Casey Schaufler
2014-11-07 14:49 ` David Howells
2014-11-07 14:49 ` David Howells
2014-11-07 21:22 ` Paul Moore [this message]
2014-11-07 21:22 ` Paul Moore
2014-11-07 22:10 ` David Howells
2014-11-07 22:10 ` David Howells
2014-11-10 15:28 ` Paul Moore
2014-11-10 15:28 ` Paul Moore
2014-11-05 15:42 ` [PATCH 2/7] Overlayfs: Use copy-up security hooks David Howells
2014-11-07 21:39 ` Paul Moore
2014-11-07 21:39 ` Paul Moore
2014-11-07 22:05 ` David Howells
2014-11-07 22:05 ` David Howells
2014-11-10 15:45 ` Paul Moore
2014-11-10 15:45 ` Paul Moore
2014-11-05 15:42 ` [PATCH 3/7] SELinux: Stub in copy-up handling David Howells
2014-11-07 21:44 ` Paul Moore
2014-11-07 21:44 ` Paul Moore
2014-11-07 22:08 ` David Howells
2014-11-07 22:08 ` David Howells
2014-11-10 15:47 ` Paul Moore
2014-11-10 15:47 ` Paul Moore
2014-11-05 15:42 ` [PATCH 4/7] Security: Pass the union-layer file path into security_file_open() David Howells
2014-11-05 15:43 ` [PATCH 5/7] SELinux: Handle opening of a unioned file David Howells
2014-11-05 16:35 ` Stephen Smalley
2014-11-06 12:03 ` David Howells
2014-11-06 12:03 ` David Howells
2014-11-06 13:13 ` Stephen Smalley
2014-11-06 13:13 ` Stephen Smalley
2014-11-06 13:34 ` David Howells
2014-11-06 13:34 ` David Howells
2014-11-27 14:15 ` David Howells
2014-11-27 14:15 ` David Howells
2014-11-06 12:27 ` David Howells
2014-11-06 12:27 ` David Howells
2014-11-06 12:27 ` David Howells
2014-11-27 17:25 ` David Howells
2014-11-27 17:25 ` David Howells
2015-06-12 15:30 ` David Howells
2015-06-12 15:30 ` David Howells
2015-06-15 12:57 ` Stephen Smalley
2015-06-15 12:57 ` Stephen Smalley
2015-06-16 9:41 ` David Howells
2015-06-16 9:41 ` David Howells
2015-06-16 16:49 ` David Howells
2015-06-16 16:49 ` David Howells
2015-06-16 17:20 ` Stephen Smalley
2015-06-16 17:20 ` Stephen Smalley
2015-06-16 21:34 ` David Howells
2015-06-16 21:34 ` David Howells
2015-06-17 14:44 ` Stephen Smalley
2015-06-17 14:44 ` Stephen Smalley
2015-06-18 10:15 ` David Howells
2015-06-18 10:15 ` David Howells
2015-06-18 12:48 ` Stephen Smalley
2015-06-18 12:48 ` Stephen Smalley
2015-06-18 15:26 ` David Howells
2015-06-18 15:26 ` David Howells
2015-06-18 10:32 ` David Howells
2015-06-18 10:32 ` David Howells
2015-06-18 12:16 ` Stephen Smalley
2015-06-18 12:16 ` Stephen Smalley
2014-11-05 15:43 ` [PATCH 6/7] SELinux: The copy-up operation must have read permission on the lower file David Howells
2014-11-05 16:43 ` Stephen Smalley
2014-11-05 17:54 ` Stephen Smalley
2014-11-06 13:39 ` Stephen Smalley
2014-11-27 14:17 ` David Howells
2014-11-27 14:17 ` David Howells
2014-11-27 14:21 ` David Howells
2014-11-27 14:21 ` David Howells
2014-11-27 14:21 ` David Howells
2014-11-05 15:43 ` [PATCH 7/7] SELinux: Check against union and lower labels for file ops on lower files David Howells
2014-11-06 17:35 ` [PATCH 0/7] Security: Provide unioned file support Casey Schaufler
2014-11-06 17:35 ` Casey Schaufler
2014-11-06 17:58 ` David Howells
2014-11-06 17:58 ` David Howells
2014-11-06 18:40 ` Casey Schaufler
2014-11-06 18:40 ` Casey Schaufler
2014-11-07 15:21 ` David Howells
2014-11-07 15:21 ` David Howells
2014-11-07 18:54 ` Daniel J Walsh
2014-11-07 18:54 ` Daniel J Walsh
2014-11-09 1:31 ` Casey Schaufler
2014-11-09 1:31 ` Casey Schaufler
2014-11-10 13:59 ` Daniel J Walsh
2014-11-10 13:59 ` Daniel J Walsh
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