From: Ian Kent <ikent@redhat.com>
To: Kernel Mailing List <linux-kernel@vger.kernel.org>
Cc: "J. Bruce Fields" <bfields@fieldses.org>,
Oleg Nesterov <onestero@redhat.com>,
Stanislav Kinsbursky <skinsbursky@parallels.com>,
Trond Myklebust <trond.myklebust@primarydata.com>,
David Howells <dhowells@redhat.com>,
Benjamin Coddington <bcodding@redhat.com>,
Al Viro <viro@ZenIV.linux.org.uk>,
"Eric W. Biederman" <ebiederm@xmission.com>
Subject: [RFC PATCH 4/4] KEYS: exec request-key within the requesting task's namespace
Date: Tue, 25 Nov 2014 09:07:42 +0800 [thread overview]
Message-ID: <20141125010741.4974.7022.stgit@pluto.fritz.box> (raw)
In-Reply-To: <20141125005255.4974.54193.stgit@pluto.fritz.box>
From: Benjamin Coddington <bcodding@redhat.com>
Copy the current task's namespaces into the request-key userspace helper to
restrict contained processes from executing key instantiation processes
outside their containers.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Ian Kent <ikent@redhat.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: J. Bruce Fields <bfields@fieldses.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: Stanislav Kinsbursky <skinsbursky@parallels.com>
Cc: Oleg Nesterov <onestero@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
---
security/keys/request_key.c | 45 +++++++++++++++++++++++++++++++++++++------
1 file changed, 39 insertions(+), 6 deletions(-)
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index bb4337c..b03feec 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -17,6 +17,8 @@
#include <linux/err.h>
#include <linux/keyctl.h>
#include <linux/slab.h>
+#include <linux/nsproxy.h>
+#include <linux/mount.h>
#include "internal.h"
#define key_negative_timeout 60 /* default timeout on a negative key's existence */
@@ -46,6 +48,11 @@ void complete_request_key(struct key_construction *cons, int error)
}
EXPORT_SYMBOL(complete_request_key);
+struct request_key_info {
+ struct key *keyring;
+ struct nsproxy *nsproxy;
+};
+
/*
* Initialise a usermode helper that is going to have a specific session
* keyring.
@@ -55,9 +62,14 @@ EXPORT_SYMBOL(complete_request_key);
*/
static int umh_keys_init(struct subprocess_info *info, struct cred *cred)
{
- struct key *keyring = info->data;
+ struct request_key_info *rki = info->data;
+ struct nsproxy *ns = rki->nsproxy;
- return install_session_keyring_to_cred(cred, keyring);
+ if (ns) {
+ mntns_setfs(ns->mnt_ns);
+ switch_task_namespaces(current, ns);
+ }
+ return install_session_keyring_to_cred(cred, rki->keyring);
}
/*
@@ -65,8 +77,9 @@ static int umh_keys_init(struct subprocess_info *info, struct cred *cred)
*/
static void umh_keys_cleanup(struct subprocess_info *info)
{
- struct key *keyring = info->data;
- key_put(keyring);
+ struct request_key_info *rki = info->data;
+ key_put(rki->keyring);
+ kfree(rki);
}
/*
@@ -76,12 +89,32 @@ static int call_usermodehelper_keys(char *path, char **argv, char **envp,
struct key *session_keyring, int wait)
{
struct subprocess_info *info;
+ struct request_key_info *rki;
+ struct nsproxy *ns;
+
+ ns = umh_open_ns();
+ if (ns && IS_ERR(ns))
+ return PTR_ERR(ns);
+
+ rki = kmalloc(sizeof(*rki), GFP_KERNEL);
+ if (!rki) {
+ if (ns)
+ free_nsproxy(ns);
+ return -ENOMEM;
+ }
+
+ rki->keyring = session_keyring;
+ rki->nsproxy = ns;
info = call_usermodehelper_setup(path, argv, envp, GFP_KERNEL,
umh_keys_init, umh_keys_cleanup,
- session_keyring);
- if (!info)
+ rki);
+ if (!info) {
+ if (ns)
+ free_nsproxy(ns);
+ kfree(rki);
return -ENOMEM;
+ }
key_get(session_keyring);
return call_usermodehelper_exec(info, wait);
prev parent reply other threads:[~2014-11-25 1:07 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-25 1:07 [RFC PATCH 0/4] Namespace contrained helper execution Ian Kent
2014-11-25 1:07 ` [RFC PATCH 1/4] vfs - fs/namespaces.c: break out mntns_setfs() from mntns_install() Ian Kent
2014-11-25 1:07 ` [RFC PATCH 2/4] nsproxy - make create_new_namespaces() non-static Ian Kent
2014-11-25 1:07 ` [RFC PATCH 3/4] kmod - add call_usermodehelper_ns() helper Ian Kent
2014-11-25 21:52 ` Oleg Nesterov
2014-11-25 22:06 ` Oleg Nesterov
2014-11-25 22:23 ` Eric W. Biederman
2014-11-25 23:07 ` Ian Kent
2014-11-25 23:19 ` Eric W. Biederman
2014-11-25 23:50 ` Ian Kent
2014-11-26 0:44 ` Ian Kent
2014-11-26 1:38 ` Eric W. Biederman
2014-12-01 21:56 ` Benjamin Coddington
2014-12-02 23:33 ` Ian Kent
2014-12-03 16:49 ` Eric W. Biederman
2014-12-03 18:14 ` Benjamin Coddington
2014-12-03 22:53 ` Ian Kent
2014-12-03 23:34 ` Ian Kent
2014-11-25 23:14 ` Ian Kent
2014-11-26 11:46 ` David Howells
2014-11-26 15:00 ` Eric W. Biederman
2014-11-26 22:57 ` J. Bruce Fields
2014-11-25 22:36 ` Ian Kent
2014-11-25 23:27 ` Eric W. Biederman
2014-11-28 0:19 ` Ian Kent
2014-11-27 1:30 ` Oleg Nesterov
2014-11-25 1:07 ` Ian Kent [this message]
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