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-rw-r--r--security/keys/process_keys.c141
1 files changed, 76 insertions, 65 deletions
diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index 42defae1e16..0cf8a130a26 100644
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -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);