From: Stephen Smalley <sds@tycho.nsa.gov>
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, drquigl <drquigl@tycho.nsa.gov>,
Eric Paris <eparis@parisplace.org>
Subject: Re: [PATCH 5/7] SELinux: Handle opening of a unioned file
Date: Mon, 15 Jun 2015 08:57:41 -0400 [thread overview]
Message-ID: <557ECBC5.7000705@tycho.nsa.gov> (raw)
In-Reply-To: <8813.1434123054@warthog.procyon.org.uk>
On 06/12/2015 11:30 AM, David Howells wrote:
> Hi Stephen,
>
> David Howells <dhowells@redhat.com> wrote:
>
>> Stephen Smalley <sds@tycho.nsa.gov> wrote:
>>
>>> Also, would be good to create a common helper for use here, by
>>> selinux_dentry_init_security(), selinux_inode_init_security(), and
>>> may_create(). Already some seeming potential for inconsistencies there.
>>
>> selinux_dentry_init_security() and selinux_inode_init_security() do
>> something different depending on SECURITY_FS_USE_MNTPOINT. Is the dentry
>> variant wrong? Shouldn't it be using the mountpoint label if that flag _is_
>> set?
>
> Any answer to that?
It looks like commit 415103f9932d45f7927f4b17e3a9a13834cdb9a1 changed
selinux_inode_init_security()'s handling of SECURITY_FS_USE_MNTPOINT,
and this change was never propagated to selinux_dentry_init_security().
However, that commit also did not update
security/selinux/hooks.c:may_create()'s logic for computing the new file
label when checking CREATE permission, and therefore introduced a
potential inconsistency between the label used for the permission check
and the label assigned to the inode.
That's why I suggested that we need a common helper for all three to
ensure consistency there.
WARNING: multiple messages have this Message-ID (diff)
From: Stephen Smalley <sds@tycho.nsa.gov>
To: David Howells <dhowells@redhat.com>
Cc: linux-unionfs@vger.kernel.org, linux-kernel@vger.kernel.org,
drquigl <drquigl@tycho.nsa.gov>,
linux-security-module@vger.kernel.org, selinux@tycho.nsa.gov,
linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH 5/7] SELinux: Handle opening of a unioned file
Date: Mon, 15 Jun 2015 08:57:41 -0400 [thread overview]
Message-ID: <557ECBC5.7000705@tycho.nsa.gov> (raw)
In-Reply-To: <8813.1434123054@warthog.procyon.org.uk>
On 06/12/2015 11:30 AM, David Howells wrote:
> Hi Stephen,
>
> David Howells <dhowells@redhat.com> wrote:
>
>> Stephen Smalley <sds@tycho.nsa.gov> wrote:
>>
>>> Also, would be good to create a common helper for use here, by
>>> selinux_dentry_init_security(), selinux_inode_init_security(), and
>>> may_create(). Already some seeming potential for inconsistencies there.
>>
>> selinux_dentry_init_security() and selinux_inode_init_security() do
>> something different depending on SECURITY_FS_USE_MNTPOINT. Is the dentry
>> variant wrong? Shouldn't it be using the mountpoint label if that flag _is_
>> set?
>
> Any answer to that?
It looks like commit 415103f9932d45f7927f4b17e3a9a13834cdb9a1 changed
selinux_inode_init_security()'s handling of SECURITY_FS_USE_MNTPOINT,
and this change was never propagated to selinux_dentry_init_security().
However, that commit also did not update
security/selinux/hooks.c:may_create()'s logic for computing the new file
label when checking CREATE permission, and therefore introduced a
potential inconsistency between the label used for the permission check
and the label assigned to the inode.
That's why I suggested that we need a common helper for all three to
ensure consistency there.
next prev parent reply other threads:[~2015-06-15 12:59 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
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 [this message]
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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