KEYS: Better handling of errors from construct_alloc_key()
Errors from construct_alloc_key() shouldn't just be ignored in the way they are
by construct_key_and_link(). The only error that can be ignored so is
EINPROGRESS as that is used to indicate that we've found a key and don't need
to construct one.
We don't, however, handle ENOMEM, EDQUOT or EACCES to indicate allocation
failures of one sort or another.
Reported-by: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index d737cea..1bc3858 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -302,6 +302,7 @@
const struct cred *cred = current_cred();
struct key *key;
key_ref_t key_ref;
+ int ret;
kenter("%s,%s,,,", type->name, description);
@@ -337,14 +338,23 @@
kleave(" = 0 [%d]", key_serial(key));
return 0;
+ /* the key is now present - we tell the caller that we found it by
+ * returning -EINPROGRESS */
key_already_present:
mutex_unlock(&key_construction_mutex);
+ ret = 0;
if (dest_keyring) {
- __key_link(dest_keyring, key_ref_to_ptr(key_ref));
+ ret = __key_link(dest_keyring, key_ref_to_ptr(key_ref));
up_write(&dest_keyring->sem);
}
mutex_unlock(&user->cons_lock);
key_put(key);
+ if (ret < 0) {
+ key_ref_put(key_ref);
+ *_key = NULL;
+ kleave(" = %d [link]", ret);
+ return ret;
+ }
*_key = key = key_ref_to_ptr(key_ref);
kleave(" = -EINPROGRESS [%d]", key_serial(key));
return -EINPROGRESS;
@@ -390,6 +400,10 @@
kdebug("cons failed");
goto construction_failed;
}
+ } else if (ret == -EINPROGRESS) {
+ ret = 0;
+ } else {
+ key = ERR_PTR(ret);
}
key_put(dest_keyring);
@@ -422,6 +436,7 @@
const struct cred *cred = current_cred();
struct key *key;
key_ref_t key_ref;
+ int ret;
kenter("%s,%s,%p,%zu,%p,%p,%lx",
type->name, description, callout_info, callout_len, aux,
@@ -435,8 +450,13 @@
key = key_ref_to_ptr(key_ref);
if (dest_keyring) {
construct_get_dest_keyring(&dest_keyring);
- key_link(dest_keyring, key);
+ ret = key_link(dest_keyring, key);
key_put(dest_keyring);
+ if (ret < 0) {
+ key_put(key);
+ key = ERR_PTR(ret);
+ goto error;
+ }
}
} else if (PTR_ERR(key_ref) != -EAGAIN) {
key = ERR_CAST(key_ref);