#include <linux/seq_file.h>
#include <linux/err.h>
#include <keys/keyring-type.h>
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
#include "internal.h"
+ #define rcu_dereference_locked_keyring(keyring) \
+ (rcu_dereference_protected( \
+ (keyring)->payload.subscriptions, \
+ rwsem_is_locked((struct rw_semaphore *)&(keyring)->sem)))
+
/*
* when plumbing the depths of the key tree, this sets a hard limit set on how
* deep we're willing to go
unsigned bucket = 0;
for (; *desc; desc++)
- bucket += (unsigned char) *desc;
+ bucket += (unsigned char)*desc;
return bucket & (KEYRING_NAME_HASH_SIZE - 1);
}
{
struct keyring_list *klist;
- if (keyring->description) {
+ if (keyring->description)
seq_puts(m, keyring->description);
- }
- else {
+ else
seq_puts(m, "[anon]");
- }
rcu_read_lock();
klist = rcu_dereference(keyring->payload.subscriptions);
int loop, ret;
ret = 0;
- klist = keyring->payload.subscriptions;
-
+ klist = rcu_dereference_locked_keyring(keyring);
if (klist) {
/* calculate how much data we could return */
qty = klist->nkeys * sizeof(key_serial_t);
ret = qty;
}
- error:
+error:
return ret;
} /* end keyring_read() */
key_check(keyring);
/* top keyring must have search permission to begin the search */
- err = key_task_permission(keyring_ref, cred, KEY_SEARCH);
+ err = key_task_permission(keyring_ref, cred, KEY_SEARCH);
if (err < 0) {
key_ref = ERR_PTR(err);
goto error;
rcu_read_unlock();
return ERR_PTR(-ENOKEY);
- found:
+found:
atomic_inc(&key->usage);
rcu_read_unlock();
return make_key_ref(key, possessed);
struct key *keyring;
int bucket;
- keyring = ERR_PTR(-EINVAL);
if (!name)
- goto error;
+ return ERR_PTR(-EINVAL);
bucket = keyring_hash(name);
KEY_SEARCH) < 0)
continue;
- /* we've got a match */
- atomic_inc(&keyring->usage);
- read_unlock(&keyring_name_lock);
- goto error;
+ /* we've got a match but we might end up racing with
+ * key_cleanup() if the keyring is currently 'dead'
+ * (ie. it has a zero usage count) */
+ if (!atomic_inc_not_zero(&keyring->usage))
+ continue;
+ goto out;
}
}
- read_unlock(&keyring_name_lock);
keyring = ERR_PTR(-ENOKEY);
-
- error:
+ out:
+ read_unlock(&keyring_name_lock);
return keyring;
} /* end find_keyring_by_name() */
sp = 0;
/* start processing a new keyring */
- descend:
+descend:
if (test_bit(KEY_FLAG_REVOKED, &subtree->flags))
goto not_this_keyring;
goto not_this_keyring;
kix = 0;
- ascend:
+ascend:
/* iterate through the remaining keys in this keyring */
for (; kix < keylist->nkeys; kix++) {
key = keylist->keys[kix];
/* the keyring we're looking at was disqualified or didn't contain a
* matching key */
- not_this_keyring:
+not_this_keyring:
if (sp > 0) {
/* resume the checking of a keyring higher up in the tree */
sp--;
ret = 0; /* no cycles detected */
- error:
+error:
rcu_read_unlock();
return ret;
- too_deep:
+too_deep:
ret = -ELOOP;
goto error;
- cycle_detected:
+cycle_detected:
ret = -EDEADLK;
goto error;
if (keyring->type != &key_type_keyring)
goto error;
- /* serialise link/link calls to prevent parallel calls causing a
- * cycle when applied to two keyring in opposite orders */
- down_write(&keyring_serialise_link_sem);
-
- /* check that we aren't going to create a cycle adding one keyring to
- * another */
+ /* do some special keyring->keyring link checks */
if (key->type == &key_type_keyring) {
+ /* serialise link/link calls to prevent parallel calls causing
+ * a cycle when applied to two keyring in opposite orders */
+ down_write(&keyring_serialise_link_sem);
+
+ /* check that we aren't going to create a cycle adding one
+ * keyring to another */
ret = keyring_detect_cycle(keyring, key);
if (ret < 0)
goto error2;
}
/* see if there's a matching key we can displace */
- klist = keyring->payload.subscriptions;
-
+ klist = rcu_dereference_locked_keyring(keyring);
if (klist && klist->nkeys > 0) {
struct key_type *type = key->type;
if (ret < 0)
goto error2;
- klist = keyring->payload.subscriptions;
-
if (klist && klist->nkeys < klist->maxkeys) {
/* there's sufficient slack space to add directly */
atomic_inc(&key->usage);
smp_wmb();
klist->nkeys++;
smp_wmb();
- }
- else {
+ } else {
/* grow the key list */
max = 4;
if (klist)
done:
ret = 0;
error2:
- up_write(&keyring_serialise_link_sem);
+ if (key->type == &key_type_keyring)
+ up_write(&keyring_serialise_link_sem);
error:
return ret;
down_write(&keyring->sem);
- klist = keyring->payload.subscriptions;
+ klist = rcu_dereference_locked_keyring(keyring);
if (klist) {
/* search the keyring for the key */
for (loop = 0; loop < klist->nkeys; loop++)
/* detach the pointer block with the locks held */
down_write(&keyring->sem);
- klist = keyring->payload.subscriptions;
+ klist = rcu_dereference_locked_keyring(keyring);
if (klist) {
/* adjust the quota */
key_payload_reserve(keyring,
*/
static void keyring_revoke(struct key *keyring)
{
- struct keyring_list *klist = keyring->payload.subscriptions;
+ struct keyring_list *klist;
+
+ klist = rcu_dereference_locked_keyring(keyring);
/* adjust the quota */
key_payload_reserve(keyring, 0);
down_write(&keyring->sem);
- klist = keyring->payload.subscriptions;
+ klist = rcu_dereference_locked_keyring(keyring);
if (!klist)
goto no_klist;
}
/* attach the auth key to the session keyring */
- ret = __key_link(keyring, authkey);
+ ret = key_link(keyring, authkey);
if (ret < 0)
goto error_link;
const struct cred *cred = current_cred();
struct key *key;
key_ref_t key_ref;
+ int ret;
kenter("%s,%s,,,", type->name, description);
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;
kdebug("cons failed");
goto construction_failed;
}
+ } else if (ret == -EINPROGRESS) {
+ ret = 0;
+ } else {
+ key = ERR_PTR(ret);
}
key_put(dest_keyring);
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,
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);
projects / deliverable / linux.git / commitdiff
