From: David Howells <dhowells@redhat.com>
To: Paul Moore <paul@paul-moore.com>
Cc: dhowells@redhat.com, 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 3/7] SELinux: Stub in copy-up handling
Date: Fri, 07 Nov 2014 22:08:48 +0000 [thread overview]
Message-ID: <3177.1415398128@warthog.procyon.org.uk> (raw)
In-Reply-To: <1791526.rYj1Ea3vWT@sifl>
Paul Moore <paul@paul-moore.com> wrote:
> > +static int selinux_inode_copy_up_xattr(struct dentry *src, struct dentry
> > ...*dst,
> > + const char *name, void *value, size_t *size)
> > +{
> > + if (strcmp(name, XATTR_NAME_SELINUX) == 0)
> > + return 1; /* Discard */
>
> I understand that this is just a stub, but I we need to discuss this at some
> point and I figure better in this patch than elsewhere where it might get
> lost.
>
> For the docker, context= mount use case (similar to SELinux/sVirt) dropping
> the SELinux xattr is probably an okay behavior. However, I would expect that
> ultimately this is something we would want to control by policy and/or the
> presence of a context= label.
The problem is that the label you actually want has already been set and you
have to be careful not to overwrite it.
The other hook (->inode_copy_up) is called first to label the destination
inode - and that has access to the source file also so it can label the
destination with consideration of the attributes on the source. Normally, the
attributes on the source will be in memory attached to the source inode, I
would imagine.
David
WARNING: multiple messages have this Message-ID (diff)
From: David Howells <dhowells@redhat.com>
To: Paul Moore <paul@paul-moore.com>
Cc: linux-unionfs@vger.kernel.org, linux-kernel@vger.kernel.org,
dhowells@redhat.com, linux-security-module@vger.kernel.org,
selinux@tycho.nsa.gov, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH 3/7] SELinux: Stub in copy-up handling
Date: Fri, 07 Nov 2014 22:08:48 +0000 [thread overview]
Message-ID: <3177.1415398128@warthog.procyon.org.uk> (raw)
In-Reply-To: <1791526.rYj1Ea3vWT@sifl>
Paul Moore <paul@paul-moore.com> wrote:
> > +static int selinux_inode_copy_up_xattr(struct dentry *src, struct dentry
> > ...*dst,
> > + const char *name, void *value, size_t *size)
> > +{
> > + if (strcmp(name, XATTR_NAME_SELINUX) == 0)
> > + return 1; /* Discard */
>
> I understand that this is just a stub, but I we need to discuss this at some
> point and I figure better in this patch than elsewhere where it might get
> lost.
>
> For the docker, context= mount use case (similar to SELinux/sVirt) dropping
> the SELinux xattr is probably an okay behavior. However, I would expect that
> ultimately this is something we would want to control by policy and/or the
> presence of a context= label.
The problem is that the label you actually want has already been set and you
have to be careful not to overwrite it.
The other hook (->inode_copy_up) is called first to label the destination
inode - and that has access to the source file also so it can label the
destination with consideration of the attributes on the source. Normally, the
attributes on the source will be in memory attached to the source inode, I
would imagine.
David
next prev parent reply other threads:[~2014-11-07 22:08 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 [this message]
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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