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-rw-r--r--Documentation/keys-request-key.txt22
-rw-r--r--Documentation/keys.txt24
-rw-r--r--include/linux/key.h12
-rw-r--r--include/linux/keyctl.h2
-rw-r--r--include/linux/sched.h1
-rw-r--r--security/keys/compat.c3
-rw-r--r--security/keys/internal.h4
-rw-r--r--security/keys/keyctl.c107
-rw-r--r--security/keys/keyring.c45
-rw-r--r--security/keys/permission.c32
-rw-r--r--security/keys/process_keys.c71
-rw-r--r--security/keys/request_key.c108
-rw-r--r--security/keys/request_key_auth.c192
13 files changed, 378 insertions, 245 deletions
diff --git a/Documentation/keys-request-key.txt b/Documentation/keys-request-key.txt
index 5f2b9c5edbb..22488d79116 100644
--- a/Documentation/keys-request-key.txt
+++ b/Documentation/keys-request-key.txt
@@ -56,10 +56,12 @@ A request proceeds in the following manner:
(4) request_key() then forks and executes /sbin/request-key with a new session
keyring that contains a link to auth key V.
- (5) /sbin/request-key execs an appropriate program to perform the actual
+ (5) /sbin/request-key assumes the authority associated with key U.
+
+ (6) /sbin/request-key execs an appropriate program to perform the actual
instantiation.
- (6) The program may want to access another key from A's context (say a
+ (7) The program may want to access another key from A's context (say a
Kerberos TGT key). It just requests the appropriate key, and the keyring
search notes that the session keyring has auth key V in its bottom level.
@@ -67,19 +69,19 @@ A request proceeds in the following manner:
UID, GID, groups and security info of process A as if it was process A,
and come up with key W.
- (7) The program then does what it must to get the data with which to
+ (8) The program then does what it must to get the data with which to
instantiate key U, using key W as a reference (perhaps it contacts a
Kerberos server using the TGT) and then instantiates key U.
- (8) Upon instantiating key U, auth key V is automatically revoked so that it
+ (9) Upon instantiating key U, auth key V is automatically revoked so that it
may not be used again.
- (9) The program then exits 0 and request_key() deletes key V and returns key
+(10) The program then exits 0 and request_key() deletes key V and returns key
U to the caller.
-This also extends further. If key W (step 5 above) didn't exist, key W would be
-created uninstantiated, another auth key (X) would be created [as per step 3]
-and another copy of /sbin/request-key spawned [as per step 4]; but the context
+This also extends further. If key W (step 7 above) didn't exist, key W would be
+created uninstantiated, another auth key (X) would be created (as per step 3)
+and another copy of /sbin/request-key spawned (as per step 4); but the context
specified by auth key X will still be process A, as it was in auth key V.
This is because process A's keyrings can't simply be attached to
@@ -138,8 +140,8 @@ until one succeeds:
(3) The process's session keyring is searched.
- (4) If the process has a request_key() authorisation key in its session
- keyring then:
+ (4) If the process has assumed the authority associated with a request_key()
+ authorisation key then:
(a) If extant, the calling process's thread keyring is searched.
diff --git a/Documentation/keys.txt b/Documentation/keys.txt
index eeda00f82d2..aaa01b0e3ee 100644
--- a/Documentation/keys.txt
+++ b/Documentation/keys.txt
@@ -308,6 +308,8 @@ process making the call:
KEY_SPEC_USER_KEYRING -4 UID-specific keyring
KEY_SPEC_USER_SESSION_KEYRING -5 UID-session keyring
KEY_SPEC_GROUP_KEYRING -6 GID-specific keyring
+ KEY_SPEC_REQKEY_AUTH_KEY -7 assumed request_key()
+ authorisation key
The main syscalls are:
@@ -645,6 +647,28 @@ The keyctl syscall functions are:
or expired keys.
+ (*) Assume the authority granted to instantiate a key
+
+ long keyctl(KEYCTL_ASSUME_AUTHORITY, key_serial_t key);
+
+ This assumes or divests the authority required to instantiate the
+ specified key. Authority can only be assumed if the thread has the
+ authorisation key associated with the specified key in its keyrings
+ somewhere.
+
+ Once authority is assumed, searches for keys will also search the
+ requester's keyrings using the requester's security label, UID, GID and
+ groups.
+
+ If the requested authority is unavailable, error EPERM will be returned,
+ likewise if the authority has been revoked because the target key is
+ already instantiated.
+
+ If the specified key is 0, then any assumed authority will be divested.
+
+ The assumed authorititive key is inherited across fork and exec.
+
+
===============
KERNEL SERVICES
===============
diff --git a/include/linux/key.h b/include/linux/key.h
index 4d189e51bc6..cbf464ad958 100644
--- a/include/linux/key.h
+++ b/include/linux/key.h
@@ -177,6 +177,8 @@ struct key {
/*
* kernel managed key type definition
*/
+typedef int (*request_key_actor_t)(struct key *key, struct key *authkey, const char *op);
+
struct key_type {
/* name of the type */
const char *name;
@@ -218,6 +220,16 @@ struct key_type {
*/
long (*read)(const struct key *key, char __user *buffer, size_t buflen);
+ /* handle request_key() for this type instead of invoking
+ * /sbin/request-key (optional)
+ * - key is the key to instantiate
+ * - authkey is the authority to assume when instantiating this key
+ * - op is the operation to be done, usually "create"
+ * - the call must not return until the instantiation process has run
+ * its course
+ */
+ request_key_actor_t request_key;
+
/* internal fields */
struct list_head link; /* link in types list */
};
diff --git a/include/linux/keyctl.h b/include/linux/keyctl.h
index ec8f3d622a8..3365945640c 100644
--- a/include/linux/keyctl.h
+++ b/include/linux/keyctl.h
@@ -19,6 +19,7 @@
#define KEY_SPEC_USER_KEYRING -4 /* - key ID for UID-specific keyring */
#define KEY_SPEC_USER_SESSION_KEYRING -5 /* - key ID for UID-session keyring */
#define KEY_SPEC_GROUP_KEYRING -6 /* - key ID for GID-specific keyring */
+#define KEY_SPEC_REQKEY_AUTH_KEY -7 /* - key ID for assumed request_key auth key */
/* request-key default keyrings */
#define KEY_REQKEY_DEFL_NO_CHANGE -1
@@ -47,5 +48,6 @@
#define KEYCTL_NEGATE 13 /* negate a partially constructed key */
#define KEYCTL_SET_REQKEY_KEYRING 14 /* set default request-key keyring */
#define KEYCTL_SET_TIMEOUT 15 /* set key timeout */
+#define KEYCTL_ASSUME_AUTHORITY 16 /* assume request_key() authorisation */
#endif /* _LINUX_KEYCTL_H */
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 20bd7074910..78eb92ae4d9 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -771,6 +771,7 @@ struct task_struct {
unsigned keep_capabilities:1;
struct user_struct *user;
#ifdef CONFIG_KEYS
+ struct key *request_key_auth; /* assumed request_key authority */
struct key *thread_keyring; /* keyring private to this thread */
unsigned char jit_keyring; /* default keyring to attach requested keys to */
#endif
diff --git a/security/keys/compat.c b/security/keys/compat.c
index e8e7ef4a290..bcdb2853373 100644
--- a/security/keys/compat.c
+++ b/security/keys/compat.c
@@ -77,6 +77,9 @@ asmlinkage long compat_sys_keyctl(u32 option,
case KEYCTL_SET_TIMEOUT:
return keyctl_set_timeout(arg2, arg3);
+ case KEYCTL_ASSUME_AUTHORITY:
+ return keyctl_assume_authority(arg2);
+
default:
return -EOPNOTSUPP;
}
diff --git a/security/keys/internal.h b/security/keys/internal.h
index 51f37c0bdb3..e066e605795 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -107,12 +107,13 @@ extern struct key *request_key_and_link(struct key_type *type,
struct request_key_auth {
struct key *target_key;
struct task_struct *context;
+ const char *callout_info;
pid_t pid;
};
extern struct key_type key_type_request_key_auth;
extern struct key *request_key_auth_new(struct key *target,
- struct key **_rkakey);
+ const char *callout_info);
extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
@@ -137,6 +138,7 @@ extern long keyctl_instantiate_key(key_serial_t, const void __user *,
extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
extern long keyctl_set_reqkey_keyring(int);
extern long keyctl_set_timeout(key_serial_t, unsigned);
+extern long keyctl_assume_authority(key_serial_t);
/*
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 299f0ae11cf..3d2ebae029c 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -834,6 +834,17 @@ long keyctl_instantiate_key(key_serial_t id,
if (plen > 32767)
goto error;
+ /* the appropriate instantiation authorisation key must have been
+ * assumed before calling this */
+ ret = -EPERM;
+ instkey = current->request_key_auth;
+ if (!instkey)
+ goto error;
+
+ rka = instkey->payload.data;
+ if (rka->target_key->serial != id)
+ goto error;
+
/* pull the payload in if one was supplied */
payload = NULL;
@@ -848,15 +859,6 @@ long keyctl_instantiate_key(key_serial_t id,
goto error2;
}
- /* find the instantiation authorisation key */
- instkey = key_get_instantiation_authkey(id);
- if (IS_ERR(instkey)) {
- ret = PTR_ERR(instkey);
- goto error2;
- }
-
- rka = instkey->payload.data;
-
/* find the destination keyring amongst those belonging to the
* requesting task */
keyring_ref = NULL;
@@ -865,7 +867,7 @@ long keyctl_instantiate_key(key_serial_t id,
KEY_WRITE);
if (IS_ERR(keyring_ref)) {
ret = PTR_ERR(keyring_ref);
- goto error3;
+ goto error2;
}
}
@@ -874,11 +876,17 @@ long keyctl_instantiate_key(key_serial_t id,
key_ref_to_ptr(keyring_ref), instkey);
key_ref_put(keyring_ref);
- error3:
- key_put(instkey);
- error2:
+
+ /* discard the assumed authority if it's just been disabled by
+ * instantiation of the key */
+ if (ret == 0) {
+ key_put(current->request_key_auth);
+ current->request_key_auth = NULL;
+ }
+
+error2:
kfree(payload);
- error:
+error:
return ret;
} /* end keyctl_instantiate_key() */
@@ -895,14 +903,16 @@ long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid)
key_ref_t keyring_ref;
long ret;
- /* find the instantiation authorisation key */
- instkey = key_get_instantiation_authkey(id);
- if (IS_ERR(instkey)) {
- ret = PTR_ERR(instkey);
+ /* the appropriate instantiation authorisation key must have been
+ * assumed before calling this */
+ ret = -EPERM;
+ instkey = current->request_key_auth;
+ if (!instkey)
goto error;
- }
rka = instkey->payload.data;
+ if (rka->target_key->serial != id)
+ goto error;
/* find the destination keyring if present (which must also be
* writable) */
@@ -911,7 +921,7 @@ long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid)
keyring_ref = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE);
if (IS_ERR(keyring_ref)) {
ret = PTR_ERR(keyring_ref);
- goto error2;
+ goto error;
}
}
@@ -920,9 +930,15 @@ long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid)
key_ref_to_ptr(keyring_ref), instkey);
key_ref_put(keyring_ref);
- error2:
- key_put(instkey);
- error:
+
+ /* discard the assumed authority if it's just been disabled by
+ * instantiation of the key */
+ if (ret == 0) {
+ key_put(current->request_key_auth);
+ current->request_key_auth = NULL;
+ }
+
+error:
return ret;
} /* end keyctl_negate_key() */
@@ -1007,6 +1023,48 @@ error:
/*****************************************************************************/
/*
+ * assume the authority to instantiate the specified key
+ */
+long keyctl_assume_authority(key_serial_t id)
+{
+ struct key *authkey;
+ long ret;
+
+ /* special key IDs aren't permitted */
+ ret = -EINVAL;
+ if (id < 0)
+ goto error;
+
+ /* we divest ourselves of authority if given an ID of 0 */
+ if (id == 0) {
+ key_put(current->request_key_auth);
+ current->request_key_auth = NULL;
+ ret = 0;
+ goto error;
+ }
+
+ /* attempt to assume the authority temporarily granted to us whilst we
+ * instantiate the specified key
+ * - the authorisation key must be in the current task's keyrings
+ * somewhere
+ */
+ authkey = key_get_instantiation_authkey(id);
+ if (IS_ERR(authkey)) {
+ ret = PTR_ERR(authkey);
+ goto error;
+ }
+
+ key_put(current->request_key_auth);
+ current->request_key_auth = authkey;
+ ret = authkey->serial;
+
+error:
+ return ret;
+
+} /* end keyctl_assume_authority() */
+
+/*****************************************************************************/
+/*
* the key control system call
*/
asmlinkage long sys_keyctl(int option, unsigned long arg2, unsigned long arg3,
@@ -1082,6 +1140,9 @@ asmlinkage long sys_keyctl(int option, unsigned long arg2, unsigned long arg3,
return keyctl_set_timeout((key_serial_t) arg2,
(unsigned) arg3);
+ case KEYCTL_ASSUME_AUTHORITY:
+ return keyctl_assume_authority((key_serial_t) arg2);
+
default:
return -EOPNOTSUPP;
}
diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index 09d92d52ef7..d65a180f888 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -481,51 +481,6 @@ key_ref_t __keyring_search_one(key_ref_t keyring_ref,
/*****************************************************************************/
/*
- * search for an instantiation authorisation key matching a target key
- * - the RCU read lock must be held by the caller
- * - a target_id of zero specifies any valid token
- */
-struct key *keyring_search_instkey(struct key *keyring,
- key_serial_t target_id)
-{
- struct request_key_auth *rka;
- struct keyring_list *klist;
- struct key *instkey;
- int loop;
-
- klist = rcu_dereference(keyring->payload.subscriptions);
- if (klist) {
- for (loop = 0; loop < klist->nkeys; loop++) {
- instkey = klist->keys[loop];
-
- if (instkey->type != &key_type_request_key_auth)
- continue;
-
- rka = instkey->payload.data;
- if (target_id && rka->target_key->serial != target_id)
- continue;
-
- /* the auth key is revoked during instantiation */
- if (!test_bit(KEY_FLAG_REVOKED, &instkey->flags))
- goto found;
-
- instkey = ERR_PTR(-EKEYREVOKED);
- goto error;
- }
- }
-
- instkey = ERR_PTR(-EACCES);
- goto error;
-
-found:
- atomic_inc(&instkey->usage);
-error:
- return instkey;
-
-} /* end keyring_search_instkey() */
-
-/*****************************************************************************/
-/*
* find a keyring with the specified name
* - all named keyrings are searched
* - only find keyrings with search permission for the process
diff --git a/security/keys/permission.c b/security/keys/permission.c
index e7f579c0eaf..3b41f9b5253 100644
--- a/security/keys/permission.c
+++ b/security/keys/permission.c
@@ -73,3 +73,35 @@ use_these_perms:
} /* end key_task_permission() */
EXPORT_SYMBOL(key_task_permission);
+
+/*****************************************************************************/
+/*
+ * validate a key
+ */
+int key_validate(struct key *key)
+{
+ struct timespec now;
+ int ret = 0;
+
+ if (key) {
+ /* check it's still accessible */
+ ret = -EKEYREVOKED;
+ if (test_bit(KEY_FLAG_REVOKED, &key->flags) ||
+ test_bit(KEY_FLAG_DEAD, &key->flags))
+ goto error;
+
+ /* check it hasn't expired */
+ ret = 0;
+ if (key->expiry) {
+ now = current_kernel_time();
+ if (now.tv_sec >= key->expiry)
+ ret = -EKEYEXPIRED;
+ }
+ }
+
+ error:
+ return ret;
+
+} /* end key_validate() */
+
+EXPORT_SYMBOL(key_validate);
diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index 566b1cc0118..74cb79eb917 100644
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -270,9 +270,14 @@ int copy_thread_group_keys(struct task_struct *tsk)
int copy_keys(unsigned long clone_flags, struct task_struct *tsk)
{
key_check(tsk->thread_keyring);
+ key_check(tsk->request_key_auth);
/* no thread keyring yet */
tsk->thread_keyring = NULL;
+
+ /* copy the request_key() authorisation for this thread */
+ key_get(tsk->request_key_auth);
+
return 0;
} /* end copy_keys() */
@@ -290,11 +295,12 @@ void exit_thread_group_keys(struct signal_struct *tg)
/*****************************************************************************/
/*
- * dispose of keys upon thread exit
+ * dispose of per-thread keys upon thread exit
*/
void exit_keys(struct task_struct *tsk)
{
key_put(tsk->thread_keyring);
+ key_put(tsk->request_key_auth);
} /* end exit_keys() */
@@ -382,7 +388,7 @@ key_ref_t search_process_keyrings(struct key_type *type,
struct task_struct *context)
{
struct request_key_auth *rka;
- key_ref_t key_ref, ret, err, instkey_ref;
+ key_ref_t key_ref, ret, err;
/* we want to return -EAGAIN or -ENOKEY if any of the keyrings were
* searchable, but we failed to find a key or we found a negative key;
@@ -461,30 +467,12 @@ key_ref_t search_process_keyrings(struct key_type *type,
err = key_ref;
break;
}
-
- /* if this process has a session keyring and that has an
- * instantiation authorisation key in the bottom level, then we
- * also search the keyrings of the process mentioned there */
- if (context != current)
- goto no_key;
-
- rcu_read_lock();
- instkey_ref = __keyring_search_one(
- make_key_ref(rcu_dereference(
- context->signal->session_keyring),
- 1),
- &key_type_request_key_auth, NULL, 0);
- rcu_read_unlock();
-
- if (IS_ERR(instkey_ref))
- goto no_key;
-
- rka = key_ref_to_ptr(instkey_ref)->payload.data;
-
- key_ref = search_process_keyrings(type, description, match,
- rka->context);
- key_ref_put(instkey_ref);
-
+ }
+ /* or search the user-session keyring */
+ else {
+ key_ref = keyring_search_aux(
+ make_key_ref(context->user->session_keyring, 1),
+ context, type, description, match);
if (!IS_ERR(key_ref))
goto found;
@@ -500,11 +488,21 @@ key_ref_t search_process_keyrings(struct key_type *type,
break;
}
}
- /* or search the user-session keyring */
- else {
- key_ref = keyring_search_aux(
- make_key_ref(context->user->session_keyring, 1),
- context, type, description, match);
+
+ /* if this process has an instantiation authorisation key, then we also
+ * search the keyrings of the process mentioned there
+ * - we don't permit access to request_key auth keys via this method
+ */
+ if (context->request_key_auth &&
+ context == current &&
+ type != &key_type_request_key_auth &&
+ key_validate(context->request_key_auth) == 0
+ ) {
+ rka = context->request_key_auth->payload.data;
+
+ key_ref = search_process_keyrings(type, description, match,
+ rka->context);
+
if (!IS_ERR(key_ref))
goto found;
@@ -521,8 +519,6 @@ key_ref_t search_process_keyrings(struct key_type *type,
}
}
-
-no_key:
/* no key - decide on the error we're going to go for */
key_ref = ret ? ret : err;
@@ -628,6 +624,15 @@ key_ref_t lookup_user_key(struct task_struct *context, key_serial_t id,
key = ERR_PTR(-EINVAL);
goto error;
+ case KEY_SPEC_REQKEY_AUTH_KEY:
+ key = context->request_key_auth;
+ if (!key)
+ goto error;
+
+ atomic_inc(&key->usage);
+ key_ref = make_key_ref(key, 1);
+ break;
+
default:
key_ref = ERR_PTR(-EINVAL);
if (id < 1)
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index 5cc4bba70db..f030a0ccbb9 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -29,28 +29,36 @@ DECLARE_WAIT_QUEUE_HEAD(request_key_conswq);
/*****************************************************************************/
/*
* request userspace finish the construction of a key
- * - execute "/sbin/request-key <op> <key> <uid> <gid> <keyring> <keyring> <keyring> <info>"
+ * - execute "/sbin/request-key <op> <key> <uid> <gid> <keyring> <keyring> <keyring>"
*/
-static int call_request_key(struct key *key,
- const char *op,
- const char *callout_info)
+static int call_sbin_request_key(struct key *key,
+ struct key *authkey,
+ const char *op)
{
struct task_struct *tsk = current;
key_serial_t prkey, sskey;
- struct key *session_keyring, *rkakey;
- char *argv[10], *envp[3], uid_str[12], gid_str[12];
+ struct key *keyring;
+ char *argv[9], *envp[3], uid_str[12], gid_str[12];
char key_str[12], keyring_str[3][12];
+ char desc[20];
int ret, i;
- kenter("{%d},%s,%s", key->serial, op, callout_info);
+ kenter("{%d},{%d},%s", key->serial, authkey->serial, op);
- /* generate a new session keyring with an auth key in it */
- session_keyring = request_key_auth_new(key, &rkakey);
- if (IS_ERR(session_keyring)) {
- ret = PTR_ERR(session_keyring);
- goto error;
+ /* allocate a new session keyring */
+ sprintf(desc, "_req.%u", key->serial);
+
+ keyring = keyring_alloc(desc, current->fsuid, current->fsgid, 1, NULL);
+ if (IS_ERR(keyring)) {
+ ret = PTR_ERR(keyring);
+ goto error_alloc;
}
+ /* attach the auth key to the session keyring */
+ ret = __key_link(keyring, authkey);
+ if (ret < 0)
+ goto error_link;
+
/* record the UID and GID */
sprintf(uid_str, "%d", current->fsuid);
sprintf(gid_str, "%d", current->fsgid);
@@ -95,22 +103,19 @@ static int call_request_key(struct key *key,
argv[i++] = keyring_str[0];
argv[i++] = keyring_str[1];
argv[i++] = keyring_str[2];
- argv[i++] = (char *) callout_info;
argv[i] = NULL;
/* do it */
- ret = call_usermodehelper_keys(argv[0], argv, envp, session_keyring, 1);
+ ret = call_usermodehelper_keys(argv[0], argv, envp, keyring, 1);
- /* dispose of the special keys */
- key_revoke(rkakey);
- key_put(rkakey);
- key_put(session_keyring);
+error_link:
+ key_put(keyring);
- error:
+error_alloc:
kleave(" = %d", ret);
return ret;
-} /* end call_request_key() */
+} /* end call_sbin_request_key() */
/*****************************************************************************/
/*
@@ -122,9 +127,10 @@ static struct key *__request_key_construction(struct key_type *type,
const char *description,
const char *callout_info)
{
+ request_key_actor_t actor;
struct key_construction cons;
struct timespec now;
- struct key *key;
+ struct key *key, *authkey;
int ret, negated;
kenter("%s,%s,%s", type->name, description, callout_info);
@@ -143,8 +149,19 @@ static struct key *__request_key_construction(struct key_type *type,
/* we drop the construction sem here on behalf of the caller */
up_write(&key_construction_sem);
+ /* allocate an authorisation key */
+ authkey = request_key_auth_new(key, callout_info);
+ if (IS_ERR(authkey)) {
+ ret = PTR_ERR(authkey);
+ authkey = NULL;
+ goto alloc_authkey_failed;
+ }
+
/* make the call */
- ret = call_request_key(key, "create", callout_info);
+ actor = call_sbin_request_key;
+ if (type->request_key)
+ actor = type->request_key;
+ ret = actor(key, authkey, "create");
if (ret < 0)
goto request_failed;
@@ -153,22 +170,29 @@ static struct key *__request_key_construction(struct key_type *type,
if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags))
goto request_failed;
+ key_revoke(authkey);
+ key_put(authkey);
+
down_write(&key_construction_sem);
list_del(&cons.link);
up_write(&key_construction_sem);
/* also give an error if the key was negatively instantiated */
- check_not_negative:
+check_not_negative:
if (test_bit(KEY_FLAG_NEGATIVE, &key->flags)) {
key_put(key);
key = ERR_PTR(-ENOKEY);
}
- out:
+out:
kleave(" = %p", key);
return key;
- request_failed:
+request_failed:
+ key_revoke(authkey);
+ key_put(authkey);
+
+alloc_authkey_failed:
/* it wasn't instantiated
* - remove from construction queue
* - mark the key as dead
@@ -217,7 +241,7 @@ static struct key *__request_key_construction(struct key_type *type,
key = ERR_PTR(ret);
goto out;
- alloc_failed:
+alloc_failed:
up_write(&key_construction_sem);
goto out;
@@ -464,35 +488,3 @@ struct key *request_key(struct key_type *type,
} /* end request_key() */
EXPORT_SYMBOL(request_key);
-
-/*****************************************************************************/
-/*
- * validate a key
- */
-int key_validate(struct key *key)
-{
- struct timespec now;
- int ret = 0;
-
- if (key) {
- /* check it's still accessible */
- ret = -EKEYREVOKED;
- if (test_bit(KEY_FLAG_REVOKED, &key->flags) ||
- test_bit(KEY_FLAG_DEAD, &key->flags))
- goto error;
-
- /* check it hasn't expired */
- ret = 0;
- if (key->expiry) {
- now = current_kernel_time();
- if (now.tv_sec >= key->expiry)
- ret = -EKEYEXPIRED;
- }
- }
-
- error:
- return ret;
-
-} /* end key_validate() */
-
-EXPORT_SYMBOL(key_validate);
diff --git a/security/keys/request_key_auth.c b/security/keys/request_key_auth.c
index a8e4069d48c..cce6ba6b032 100644
--- a/security/keys/request_key_auth.c
+++ b/security/keys/request_key_auth.c
@@ -15,11 +15,13 @@
#include <linux/sched.h>
#include <linux/err.h>
#include <linux/seq_file.h>
+#include <asm/uaccess.h>
#include "internal.h"
static int request_key_auth_instantiate(struct key *, const void *, size_t);
static void request_key_auth_describe(const struct key *, struct seq_file *);
static void request_key_auth_destroy(struct key *);
+static long request_key_auth_read(const struct key *, char __user *, size_t);
/*
* the request-key authorisation key type definition
@@ -30,51 +32,25 @@ struct key_type key_type_request_key_auth = {
.instantiate = request_key_auth_instantiate,
.describe = request_key_auth_describe,
.destroy = request_key_auth_destroy,
+ .read = request_key_auth_read,
};
/*****************************************************************************/
/*
- * instantiate a request-key authorisation record
+ * instantiate a request-key authorisation key
*/
static int request_key_auth_instantiate(struct key *key,
const void *data,
size_t datalen)
{
- struct request_key_auth *rka, *irka;
- struct key *instkey;
- int ret;
-
- ret = -ENOMEM;
- rka = kmalloc(sizeof(*rka), GFP_KERNEL);
- if (rka) {
- /* see if the calling process is already servicing the key
- * request of another process */
- instkey = key_get_instantiation_authkey(0);
- if (!IS_ERR(instkey)) {
- /* it is - use that instantiation context here too */
- irka = instkey->payload.data;
- rka->context = irka->context;
- rka->pid = irka->pid;
- key_put(instkey);
- }
- else {
- /* it isn't - use this process as the context */
- rka->context = current;
- rka->pid = current->pid;
- }
-
- rka->target_key = key_get((struct key *) data);
- key->payload.data = rka;
- ret = 0;
- }
-
- return ret;
+ key->payload.data = (struct request_key_auth *) data;
+ return 0;
} /* end request_key_auth_instantiate() */
/*****************************************************************************/
/*
- *
+ * reading a request-key authorisation key retrieves the callout information
*/
static void request_key_auth_describe(const struct key *key,
struct seq_file *m)
@@ -83,12 +59,40 @@ static void request_key_auth_describe(const struct key *key,
seq_puts(m, "key:");
seq_puts(m, key->description);
- seq_printf(m, " pid:%d", rka->pid);
+ seq_printf(m, " pid:%d ci:%zu", rka->pid, strlen(rka->callout_info));
} /* end request_key_auth_describe() */
/*****************************************************************************/
/*
+ * read the callout_info data
+ * - the key's semaphore is read-locked
+ */
+static long request_key_auth_read(const struct key *key,
+ char __user *buffer, size_t buflen)
+{
+ struct request_key_auth *rka = key->payload.data;
+ size_t datalen;
+ long ret;
+
+ datalen = strlen(rka->callout_info);
+ ret = datalen;
+
+ /* we can return the data as is */
+ if (buffer && buflen > 0) {
+ if (buflen > datalen)
+ buflen = datalen;
+
+ if (copy_to_user(buffer, rka->callout_info, buflen) != 0)
+ ret = -EFAULT;
+ }
+
+ return ret;
+
+} /* end request_key_auth_read() */
+
+/*****************************************************************************/
+/*
* destroy an instantiation authorisation token key
*/
static void request_key_auth_destroy(struct key *key)
@@ -104,56 +108,89 @@ static void request_key_auth_destroy(struct key *key)
/*****************************************************************************/
/*
- * create a session keyring to be for the invokation of /sbin/request-key and
- * stick an authorisation token in it
+ * create an authorisation token for /sbin/request-key or whoever to gain
+ * access to the caller's security data
*/
-struct key *request_key_auth_new(struct key *target, struct key **_rkakey)
+struct key *request_key_auth_new(struct key *target, const char *callout_info)
{
- struct key *keyring, *rkakey = NULL;
+ struct request_key_auth *rka, *irka;
+ struct key *authkey = NULL;
char desc[20];
int ret;
kenter("%d,", target->serial);
- /* allocate a new session keyring */
- sprintf(desc, "_req.%u", target->serial);
+ /* allocate a auth record */
+ rka = kmalloc(sizeof(*rka), GFP_KERNEL);
+ if (!rka) {
+ kleave(" = -ENOMEM");
+ return ERR_PTR(-ENOMEM);
+ }
- keyring = keyring_alloc(desc, current->fsuid, current->fsgid, 1, NULL);
- if (IS_ERR(keyring)) {
- kleave("= %ld", PTR_ERR(keyring));
- return keyring;
+ /* see if the calling process is already servicing the key request of
+ * another process */
+ if (current->request_key_auth) {
+ /* it is - use that instantiation context here too */
+ irka = current->request_key_auth->payload.data;
+ rka->context = irka->context;
+ rka->pid = irka->pid;
}
+ else {
+ /* it isn't - use this process as the context */
+ rka->context = current;
+ rka->pid = current->pid;
+ }
+
+ rka->target_key = key_get(target);
+ rka->callout_info = callout_info;
/* allocate the auth key */
sprintf(desc, "%x", target->serial);
- rkakey = key_alloc(&key_type_request_key_auth, desc,
- current->fsuid, current->fsgid,
- KEY_POS_VIEW | KEY_USR_VIEW, 1);
- if (IS_ERR(rkakey)) {
- key_put(keyring);
- kleave("= %ld", PTR_ERR(rkakey));
- return rkakey;
+ authkey = key_alloc(&key_type_request_key_auth, desc,
+ current->fsuid, current->fsgid,
+ KEY_POS_VIEW | KEY_POS_READ | KEY_POS_SEARCH |
+ KEY_USR_VIEW, 1);
+ if (IS_ERR(authkey)) {
+ ret = PTR_ERR(authkey);
+ goto error_alloc;
}
/* construct and attach to the keyring */
- ret = key_instantiate_and_link(rkakey, target, 0, keyring, NULL);
- if (ret < 0) {
- key_revoke(rkakey);
- key_put(rkakey);
- key_put(keyring);
- kleave("= %d", ret);
- return ERR_PTR(ret);
- }
+ ret = key_instantiate_and_link(authkey, rka, 0, NULL, NULL);
+ if (ret < 0)
+ goto error_inst;
- *_rkakey = rkakey;
- kleave(" = {%d} ({%d})", keyring->serial, rkakey->serial);
- return keyring;
+ kleave(" = {%d})", authkey->serial);
+ return authkey;
+
+error_inst:
+ key_revoke(authkey);
+ key_put(authkey);
+error_alloc:
+ key_put(rka->target_key);
+ kfree(rka);
+ kleave("= %d", ret);
+ return ERR_PTR(ret);
} /* end request_key_auth_new() */
/*****************************************************************************/
/*
+ * see if an authorisation key is associated with a particular key
+ */
+static int key_get_instantiation_authkey_match(const struct key *key,
+ const void *_id)
+{
+ struct request_key_auth *rka = key->payload.data;
+ key_serial_t id = (key_serial_t)(unsigned long) _id;
+
+ return rka->target_key->serial == id;
+
+} /* end key_get_instantiation_authkey_match() */
+
+/*****************************************************************************/
+/*
* get the authorisation key for instantiation of a specific key if attached to
* the current process's keyrings
* - this key is inserted into a keyring and that is set as /sbin/request-key's
@@ -162,22 +199,27 @@ struct key *request_key_auth_new(struct key *target, struct key **_rkakey)
*/
struct key *key_get_instantiation_authkey(key_serial_t target_id)
{
- struct task_struct *tsk = current;
- struct key *instkey;
-
- /* we must have our own personal session keyring */
- if (!tsk->signal->session_keyring)
- return ERR_PTR(-EACCES);
-
- /* and it must contain a suitable request authorisation key
- * - lock RCU against session keyring changing
- */
- rcu_read_lock();
+ struct key *authkey;
+ key_ref_t authkey_ref;
+
+ authkey_ref = search_process_keyrings(
+ &key_type_request_key_auth,
+ (void *) (unsigned long) target_id,
+ key_get_instantiation_authkey_match,
+ current);
+
+ if (IS_ERR(authkey_ref)) {
+ authkey = ERR_PTR(PTR_ERR(authkey_ref));
+ goto error;
+ }
- instkey = keyring_search_instkey(
- rcu_dereference(tsk->signal->session_keyring), target_id);
+ authkey = key_ref_to_ptr(authkey_ref);
+ if (test_bit(KEY_FLAG_REVOKED, &authkey->flags)) {
+ key_put(authkey);
+ authkey = ERR_PTR(-EKEYREVOKED);
+ }
- rcu_read_unlock();
- return instkey;
+error:
+ return authkey;
} /* end key_get_instantiation_authkey() */
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-26 06:31:23 +0000