Merge tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck...
[linux-drm-fsl-dcu.git] / security / keys / process_keys.c
index 42defae1e161632e93b13b8194af1a30a09f2492..0cf8a130a267ca58fbc5599787c93b9913cfc576 100644 (file)
@@ -235,7 +235,7 @@ int install_session_keyring_to_cred(struct cred *cred, struct key *keyring)
                if (IS_ERR(keyring))
                        return PTR_ERR(keyring);
        } else {
-               atomic_inc(&keyring->usage);
+               __key_get(keyring);
        }
 
        /* install the keyring */
@@ -319,11 +319,7 @@ void key_fsgid_changed(struct task_struct *tsk)
  * In the case of a successful return, the possession attribute is set on the
  * returned key reference.
  */
-key_ref_t search_my_process_keyrings(struct key_type *type,
-                                    const void *description,
-                                    key_match_func_t match,
-                                    bool no_state_check,
-                                    const struct cred *cred)
+key_ref_t search_my_process_keyrings(struct keyring_search_context *ctx)
 {
        key_ref_t key_ref, ret, err;
 
@@ -339,10 +335,9 @@ key_ref_t search_my_process_keyrings(struct key_type *type,
        err = ERR_PTR(-EAGAIN);
 
        /* search the thread keyring first */
-       if (cred->thread_keyring) {
+       if (ctx->cred->thread_keyring) {
                key_ref = keyring_search_aux(
-                       make_key_ref(cred->thread_keyring, 1),
-                       cred, type, description, match, no_state_check);
+                       make_key_ref(ctx->cred->thread_keyring, 1), ctx);
                if (!IS_ERR(key_ref))
                        goto found;
 
@@ -358,10 +353,9 @@ key_ref_t search_my_process_keyrings(struct key_type *type,
        }
 
        /* search the process keyring second */
-       if (cred->process_keyring) {
+       if (ctx->cred->process_keyring) {
                key_ref = keyring_search_aux(
-                       make_key_ref(cred->process_keyring, 1),
-                       cred, type, description, match, no_state_check);
+                       make_key_ref(ctx->cred->process_keyring, 1), ctx);
                if (!IS_ERR(key_ref))
                        goto found;
 
@@ -379,11 +373,11 @@ key_ref_t search_my_process_keyrings(struct key_type *type,
        }
 
        /* search the session keyring */
-       if (cred->session_keyring) {
+       if (ctx->cred->session_keyring) {
                rcu_read_lock();
                key_ref = keyring_search_aux(
-                       make_key_ref(rcu_dereference(cred->session_keyring), 1),
-                       cred, type, description, match, no_state_check);
+                       make_key_ref(rcu_dereference(ctx->cred->session_keyring), 1),
+                       ctx);
                rcu_read_unlock();
 
                if (!IS_ERR(key_ref))
@@ -402,10 +396,10 @@ key_ref_t search_my_process_keyrings(struct key_type *type,
                }
        }
        /* or search the user-session keyring */
-       else if (cred->user->session_keyring) {
+       else if (ctx->cred->user->session_keyring) {
                key_ref = keyring_search_aux(
-                       make_key_ref(cred->user->session_keyring, 1),
-                       cred, type, description, match, no_state_check);
+                       make_key_ref(ctx->cred->user->session_keyring, 1),
+                       ctx);
                if (!IS_ERR(key_ref))
                        goto found;
 
@@ -437,18 +431,14 @@ found:
  *
  * Return same as search_my_process_keyrings().
  */
-key_ref_t search_process_keyrings(struct key_type *type,
-                                 const void *description,
-                                 key_match_func_t match,
-                                 const struct cred *cred)
+key_ref_t search_process_keyrings(struct keyring_search_context *ctx)
 {
        struct request_key_auth *rka;
        key_ref_t key_ref, ret = ERR_PTR(-EACCES), err;
 
        might_sleep();
 
-       key_ref = search_my_process_keyrings(type, description, match,
-                                            false, cred);
+       key_ref = search_my_process_keyrings(ctx);
        if (!IS_ERR(key_ref))
                goto found;
        err = key_ref;
@@ -457,18 +447,21 @@ key_ref_t search_process_keyrings(struct key_type *type,
         * search the keyrings of the process mentioned there
         * - we don't permit access to request_key auth keys via this method
         */
-       if (cred->request_key_auth &&
-           cred == current_cred() &&
-           type != &key_type_request_key_auth
+       if (ctx->cred->request_key_auth &&
+           ctx->cred == current_cred() &&
+           ctx->index_key.type != &key_type_request_key_auth
            ) {
+               const struct cred *cred = ctx->cred;
+
                /* defend against the auth key being revoked */
                down_read(&cred->request_key_auth->sem);
 
-               if (key_validate(cred->request_key_auth) == 0) {
-                       rka = cred->request_key_auth->payload.data;
+               if (key_validate(ctx->cred->request_key_auth) == 0) {
+                       rka = ctx->cred->request_key_auth->payload.data;
 
-                       key_ref = search_process_keyrings(type, description,
-                                                         match, rka->cred);
+                       ctx->cred = rka->cred;
+                       key_ref = search_process_keyrings(ctx);
+                       ctx->cred = cred;
 
                        up_read(&cred->request_key_auth->sem);
 
@@ -522,19 +515,23 @@ int lookup_user_key_possessed(const struct key *key, const void *target)
 key_ref_t lookup_user_key(key_serial_t id, unsigned long lflags,
                          key_perm_t perm)
 {
+       struct keyring_search_context ctx = {
+               .match  = lookup_user_key_possessed,
+               .flags  = (KEYRING_SEARCH_NO_STATE_CHECK |
+                          KEYRING_SEARCH_LOOKUP_DIRECT),
+       };
        struct request_key_auth *rka;
-       const struct cred *cred;
        struct key *key;
        key_ref_t key_ref, skey_ref;
        int ret;
 
 try_again:
-       cred = get_current_cred();
+       ctx.cred = get_current_cred();
        key_ref = ERR_PTR(-ENOKEY);
 
        switch (id) {
        case KEY_SPEC_THREAD_KEYRING:
-               if (!cred->thread_keyring) {
+               if (!ctx.cred->thread_keyring) {
                        if (!(lflags & KEY_LOOKUP_CREATE))
                                goto error;
 
@@ -546,13 +543,13 @@ try_again:
                        goto reget_creds;
                }
 
-               key = cred->thread_keyring;
-               atomic_inc(&key->usage);
+               key = ctx.cred->thread_keyring;
+               __key_get(key);
                key_ref = make_key_ref(key, 1);
                break;
 
        case KEY_SPEC_PROCESS_KEYRING:
-               if (!cred->process_keyring) {
+               if (!ctx.cred->process_keyring) {
                        if (!(lflags & KEY_LOOKUP_CREATE))
                                goto error;
 
@@ -564,13 +561,13 @@ try_again:
                        goto reget_creds;
                }
 
-               key = cred->process_keyring;
-               atomic_inc(&key->usage);
+               key = ctx.cred->process_keyring;
+               __key_get(key);
                key_ref = make_key_ref(key, 1);
                break;
 
        case KEY_SPEC_SESSION_KEYRING:
-               if (!cred->session_keyring) {
+               if (!ctx.cred->session_keyring) {
                        /* always install a session keyring upon access if one
                         * doesn't exist yet */
                        ret = install_user_keyrings();
@@ -580,13 +577,13 @@ try_again:
                                ret = join_session_keyring(NULL);
                        else
                                ret = install_session_keyring(
-                                       cred->user->session_keyring);
+                                       ctx.cred->user->session_keyring);
 
                        if (ret < 0)
                                goto error;
                        goto reget_creds;
-               } else if (cred->session_keyring ==
-                          cred->user->session_keyring &&
+               } else if (ctx.cred->session_keyring ==
+                          ctx.cred->user->session_keyring &&
                           lflags & KEY_LOOKUP_CREATE) {
                        ret = join_session_keyring(NULL);
                        if (ret < 0)
@@ -595,33 +592,33 @@ try_again:
                }
 
                rcu_read_lock();
-               key = rcu_dereference(cred->session_keyring);
-               atomic_inc(&key->usage);
+               key = rcu_dereference(ctx.cred->session_keyring);
+               __key_get(key);
                rcu_read_unlock();
                key_ref = make_key_ref(key, 1);
                break;
 
        case KEY_SPEC_USER_KEYRING:
-               if (!cred->user->uid_keyring) {
+               if (!ctx.cred->user->uid_keyring) {
                        ret = install_user_keyrings();
                        if (ret < 0)
                                goto error;
                }
 
-               key = cred->user->uid_keyring;
-               atomic_inc(&key->usage);
+               key = ctx.cred->user->uid_keyring;
+               __key_get(key);
                key_ref = make_key_ref(key, 1);
                break;
 
        case KEY_SPEC_USER_SESSION_KEYRING:
-               if (!cred->user->session_keyring) {
+               if (!ctx.cred->user->session_keyring) {
                        ret = install_user_keyrings();
                        if (ret < 0)
                                goto error;
                }
 
-               key = cred->user->session_keyring;
-               atomic_inc(&key->usage);
+               key = ctx.cred->user->session_keyring;
+               __key_get(key);
                key_ref = make_key_ref(key, 1);
                break;
 
@@ -631,29 +628,29 @@ try_again:
                goto error;
 
        case KEY_SPEC_REQKEY_AUTH_KEY:
-               key = cred->request_key_auth;
+               key = ctx.cred->request_key_auth;
                if (!key)
                        goto error;
 
-               atomic_inc(&key->usage);
+               __key_get(key);
                key_ref = make_key_ref(key, 1);
                break;
 
        case KEY_SPEC_REQUESTOR_KEYRING:
-               if (!cred->request_key_auth)
+               if (!ctx.cred->request_key_auth)
                        goto error;
 
-               down_read(&cred->request_key_auth->sem);
+               down_read(&ctx.cred->request_key_auth->sem);
                if (test_bit(KEY_FLAG_REVOKED,
-                            &cred->request_key_auth->flags)) {
+                            &ctx.cred->request_key_auth->flags)) {
                        key_ref = ERR_PTR(-EKEYREVOKED);
                        key = NULL;
                } else {
-                       rka = cred->request_key_auth->payload.data;
+                       rka = ctx.cred->request_key_auth->payload.data;
                        key = rka->dest_keyring;
-                       atomic_inc(&key->usage);
+                       __key_get(key);
                }
-               up_read(&cred->request_key_auth->sem);
+               up_read(&ctx.cred->request_key_auth->sem);
                if (!key)
                        goto error;
                key_ref = make_key_ref(key, 1);
@@ -673,9 +670,13 @@ try_again:
                key_ref = make_key_ref(key, 0);
 
                /* check to see if we possess the key */
-               skey_ref = search_process_keyrings(key->type, key,
-                                                  lookup_user_key_possessed,
-                                                  cred);
+               ctx.index_key.type              = key->type;
+               ctx.index_key.description       = key->description;
+               ctx.index_key.desc_len          = strlen(key->description);
+               ctx.match_data                  = key;
+               kdebug("check possessed");
+               skey_ref = search_process_keyrings(&ctx);
+               kdebug("possessed=%p", skey_ref);
 
                if (!IS_ERR(skey_ref)) {
                        key_put(key);
@@ -715,14 +716,14 @@ try_again:
                goto invalid_key;
 
        /* check the permissions */
-       ret = key_task_permission(key_ref, cred, perm);
+       ret = key_task_permission(key_ref, ctx.cred, perm);
        if (ret < 0)
                goto invalid_key;
 
        key->last_used_at = current_kernel_time().tv_sec;
 
 error:
-       put_cred(cred);
+       put_cred(ctx.cred);
        return key_ref;
 
 invalid_key:
@@ -733,7 +734,7 @@ invalid_key:
        /* if we attempted to install a keyring, then it may have caused new
         * creds to be installed */
 reget_creds:
-       put_cred(cred);
+       put_cred(ctx.cred);
        goto try_again;
 }
 
@@ -856,3 +857,13 @@ void key_change_session_keyring(struct callback_head *twork)
 
        commit_creds(new);
 }
+
+/*
+ * Make sure that root's user and user-session keyrings exist.
+ */
+static int __init init_root_keyring(void)
+{
+       return install_user_keyrings();
+}
+
+late_initcall(init_root_keyring);