From: Ian Kent <ik...@redhat.com>

Containerized request key helper callbacks need the ability to execute
a binary in a container's context. To do that get a token to a service
thread created within the container environment for usermode helper calls.

Signed-off-by: Ian Kent <ik...@redhat.com>
Cc: Benjamin Coddington <bcodd...@redhat.com>
Cc: Al Viro <v...@zeniv.linux.org.uk>
Cc: J. Bruce Fields <bfie...@fieldses.org>
Cc: David Howells <dhowe...@redhat.com>
Cc: Trond Myklebust <trond.mykleb...@primarydata.com>
Cc: Oleg Nesterov <onest...@redhat.com>
Cc: Eric W. Biederman <ebied...@xmission.com>
Cc: Jeff Layton <jeff.lay...@primarydata.com>
---
 include/linux/key.h         |    3 +++
 security/keys/gc.c          |    2 ++
 security/keys/key.c         |    5 +++++
 security/keys/request_key.c |   34 +++++++++++++++++++++++++++-------
 4 files changed, 37 insertions(+), 7 deletions(-)

diff --git a/include/linux/key.h b/include/linux/key.h
index e1d4715..144727d 100644
--- a/include/linux/key.h
+++ b/include/linux/key.h
@@ -209,6 +209,9 @@ struct key {
                } payload;
                struct assoc_array keys;
        };
+
+       /* Namespace token */
+       int umh_token;
 };
 
 extern struct key *key_alloc(struct key_type *type,
diff --git a/security/keys/gc.c b/security/keys/gc.c
index c795237..c689ffd 100644
--- a/security/keys/gc.c
+++ b/security/keys/gc.c
@@ -156,6 +156,8 @@ static noinline void key_gc_unused_keys(struct list_head 
*keys)
 
                kfree(key->description);
 
+               umh_wq_put_token(key->umh_token);
+
 #ifdef KEY_DEBUGGING
                key->magic = KEY_DEBUG_MAGIC_X;
 #endif
diff --git a/security/keys/key.c b/security/keys/key.c
index aee2ec5..3ca0825 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -18,6 +18,8 @@
 #include <linux/workqueue.h>
 #include <linux/random.h>
 #include <linux/err.h>
+#include <net/net_namespace.h>
+#include <linux/nsproxy.h>
 #include "internal.h"
 
 struct kmem_cache *key_jar;
@@ -309,6 +311,9 @@ struct key *key_alloc(struct key_type *type, const char 
*desc,
        /* publish the key by giving it a serial number */
        atomic_inc(&user->nkeys);
        key_alloc_serial(key);
+       /* If running within a container use the container namespace */
+       if (current->nsproxy->net_ns != &init_net)
+               key->umh_token = umh_wq_get_token(0, "keys");
 
 error:
        return key;
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index e865f9f..233e837 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -70,26 +70,40 @@ static void umh_keys_cleanup(struct subprocess_info *info)
 }
 
 /*
- * Call a usermode helper with a specific session keyring.
+ * Call a usermode helper with a specific session keyring and execute
+ * within a namespace.
  */
-static int call_usermodehelper_keys(char *path, char **argv, char **envp,
-                                       struct key *session_keyring, int wait)
+static int call_usermodehelper_keys_service(char *path,
+                                           char **argv, char **envp,
+                                           struct key *session_keyring,
+                                           int token, unsigned int wait)
 {
        struct subprocess_info *info;
        unsigned int gfp_mask = (wait & UMH_NO_WAIT) ?
                                        GFP_ATOMIC : GFP_KERNEL;
 
        info = call_usermodehelper_setup(path, argv, envp, gfp_mask,
-                                         umh_keys_init, umh_keys_cleanup,
-                                         session_keyring);
+                                        umh_keys_init, umh_keys_cleanup,
+                                        session_keyring);
        if (!info)
                return -ENOMEM;
+       info->wq_token = token;
 
        key_get(session_keyring);
        return call_usermodehelper_exec(info, wait);
 }
 
 /*
+ * Call a usermode helper with a specific session keyring.
+ */
+static int call_usermodehelper_keys(char *path, char **argv, char **envp,
+                                       struct key *session_keyring, int wait)
+{
+       return call_usermodehelper_keys_service(path, argv, envp,
+                                               session_keyring, 0, wait);
+}
+
+/*
  * Request userspace finish the construction of a key
  * - execute "/sbin/request-key <op> <key> <uid> <gid> <keyring> <keyring> 
<keyring>"
  */
@@ -174,8 +188,14 @@ static int call_sbin_request_key(struct key_construction 
*cons,
        argv[i] = NULL;
 
        /* do it */
-       ret = call_usermodehelper_keys(argv[0], argv, envp, keyring,
-                                      UMH_WAIT_PROC);
+       /* If running within a container use the container namespace */
+       if (key->umh_token)
+               ret = call_usermodehelper_keys_service(argv[0], argv, envp,
+                                                      keyring, key->umh_token,
+                                                      UMH_WAIT_PROC);
+       else
+               ret = call_usermodehelper_keys(argv[0], argv, envp,
+                                              keyring, UMH_WAIT_PROC);
        kdebug("usermode -> 0x%x", ret);
        if (ret >= 0) {
                /* ret is the exit/wait code */

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