diff options
Diffstat (limited to 'security')
| -rw-r--r-- | security/keys/key.c | 4 | ||||
| -rw-r--r-- | security/keys/process_keys.c | 42 | ||||
| -rw-r--r-- | security/keys/request_key_auth.c | 45 |
3 files changed, 74 insertions, 17 deletions
diff --git a/security/keys/key.c b/security/keys/key.c index 14a15abb7735..51f851557389 100644 --- a/security/keys/key.c +++ b/security/keys/key.c @@ -907,6 +907,10 @@ void key_revoke(struct key *key) * it */ down_write(&key->sem); set_bit(KEY_FLAG_REVOKED, &key->flags); + + if (key->type->revoke) + key->type->revoke(key); + up_write(&key->sem); } /* end key_revoke() */ diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c index a50a91332fe1..4d9825f9962c 100644 --- a/security/keys/process_keys.c +++ b/security/keys/process_keys.c @@ -391,6 +391,8 @@ key_ref_t search_process_keyrings(struct key_type *type, struct request_key_auth *rka; key_ref_t key_ref, ret, err; + might_sleep(); + /* 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; * otherwise we want to return a sample error (probably -EACCES) if @@ -496,27 +498,35 @@ key_ref_t search_process_keyrings(struct key_type *type, */ if (context->request_key_auth && context == current && - type != &key_type_request_key_auth && - key_validate(context->request_key_auth) == 0 + type != &key_type_request_key_auth ) { - rka = context->request_key_auth->payload.data; + /* defend against the auth key being revoked */ + down_read(&context->request_key_auth->sem); - key_ref = search_process_keyrings(type, description, match, - rka->context); + if (key_validate(context->request_key_auth) == 0) { + rka = context->request_key_auth->payload.data; - if (!IS_ERR(key_ref)) - goto found; + key_ref = search_process_keyrings(type, description, + match, rka->context); - switch (PTR_ERR(key_ref)) { - case -EAGAIN: /* no key */ - if (ret) + up_read(&context->request_key_auth->sem); + + if (!IS_ERR(key_ref)) + goto found; + + switch (PTR_ERR(key_ref)) { + case -EAGAIN: /* no key */ + if (ret) + break; + case -ENOKEY: /* negative key */ + ret = key_ref; break; - case -ENOKEY: /* negative key */ - ret = key_ref; - break; - default: - err = key_ref; - break; + default: + err = key_ref; + break; + } + } else { + up_read(&context->request_key_auth->sem); } } diff --git a/security/keys/request_key_auth.c b/security/keys/request_key_auth.c index 0ecc2e8d2bd0..cb9817ced3fd 100644 --- a/security/keys/request_key_auth.c +++ b/security/keys/request_key_auth.c @@ -20,6 +20,7 @@ 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_revoke(struct key *); static void request_key_auth_destroy(struct key *); static long request_key_auth_read(const struct key *, char __user *, size_t); @@ -31,6 +32,7 @@ struct key_type key_type_request_key_auth = { .def_datalen = sizeof(struct request_key_auth), .instantiate = request_key_auth_instantiate, .describe = request_key_auth_describe, + .revoke = request_key_auth_revoke, .destroy = request_key_auth_destroy, .read = request_key_auth_read, }; @@ -93,6 +95,24 @@ static long request_key_auth_read(const struct key *key, /*****************************************************************************/ /* + * handle revocation of an authorisation token key + * - called with the key sem write-locked + */ +static void request_key_auth_revoke(struct key *key) +{ + struct request_key_auth *rka = key->payload.data; + + kenter("{%d}", key->serial); + + if (rka->context) { + put_task_struct(rka->context); + rka->context = NULL; + } + +} /* end request_key_auth_revoke() */ + +/*****************************************************************************/ +/* * destroy an instantiation authorisation token key */ static void request_key_auth_destroy(struct key *key) @@ -101,6 +121,11 @@ static void request_key_auth_destroy(struct key *key) kenter("{%d}", key->serial); + if (rka->context) { + put_task_struct(rka->context); + rka->context = NULL; + } + key_put(rka->target_key); kfree(rka); @@ -131,14 +156,26 @@ struct key *request_key_auth_new(struct key *target, const char *callout_info) * another process */ if (current->request_key_auth) { /* it is - use that instantiation context here too */ + down_read(¤t->request_key_auth->sem); + + /* if the auth key has been revoked, then the key we're + * servicing is already instantiated */ + if (test_bit(KEY_FLAG_REVOKED, + ¤t->request_key_auth->flags)) + goto auth_key_revoked; + irka = current->request_key_auth->payload.data; rka->context = irka->context; rka->pid = irka->pid; + get_task_struct(rka->context); + + up_read(¤t->request_key_auth->sem); } else { /* it isn't - use this process as the context */ rka->context = current; rka->pid = current->pid; + get_task_struct(rka->context); } rka->target_key = key_get(target); @@ -161,9 +198,15 @@ struct key *request_key_auth_new(struct key *target, const char *callout_info) if (ret < 0) goto error_inst; - kleave(" = {%d})", authkey->serial); + kleave(" = {%d}", authkey->serial); return authkey; +auth_key_revoked: + up_read(¤t->request_key_auth->sem); + kfree(rka); + kleave("= -EKEYREVOKED"); + return ERR_PTR(-EKEYREVOKED); + error_inst: key_revoke(authkey); key_put(authkey); |