[PATCH] keys: sort out key quota system
Add the ability for key creation to overrun the user's quota in some
circumstances - notably when a session keyring is created and assigned to a
process that didn't previously have one.
This means it's still possible to log in, should PAM require the creation of a
new session keyring, and fix an overburdened key quota.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/security/keys/internal.h b/security/keys/internal.h
index e066e60..3c2877f 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -99,7 +99,8 @@
extern struct key *request_key_and_link(struct key_type *type,
const char *description,
const char *callout_info,
- struct key *dest_keyring);
+ struct key *dest_keyring,
+ unsigned long flags);
/*
* request_key authorisation
diff --git a/security/keys/key.c b/security/keys/key.c
index 51f8515..3601fdd 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -248,7 +248,7 @@
*/
struct key *key_alloc(struct key_type *type, const char *desc,
uid_t uid, gid_t gid, struct task_struct *ctx,
- key_perm_t perm, int not_in_quota)
+ key_perm_t perm, unsigned long flags)
{
struct key_user *user = NULL;
struct key *key;
@@ -269,12 +269,14 @@
/* check that the user's quota permits allocation of another key and
* its description */
- if (!not_in_quota) {
+ if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) {
spin_lock(&user->lock);
- if (user->qnkeys + 1 >= KEYQUOTA_MAX_KEYS ||
- user->qnbytes + quotalen >= KEYQUOTA_MAX_BYTES
- )
- goto no_quota;
+ if (!(flags & KEY_ALLOC_QUOTA_OVERRUN)) {
+ if (user->qnkeys + 1 >= KEYQUOTA_MAX_KEYS ||
+ user->qnbytes + quotalen >= KEYQUOTA_MAX_BYTES
+ )
+ goto no_quota;
+ }
user->qnkeys++;
user->qnbytes += quotalen;
@@ -308,7 +310,7 @@
key->payload.data = NULL;
key->security = NULL;
- if (!not_in_quota)
+ if (!(flags & KEY_ALLOC_NOT_IN_QUOTA))
key->flags |= 1 << KEY_FLAG_IN_QUOTA;
memset(&key->type_data, 0, sizeof(key->type_data));
@@ -318,7 +320,7 @@
#endif
/* let the security module know about the key */
- ret = security_key_alloc(key, ctx);
+ ret = security_key_alloc(key, ctx, flags);
if (ret < 0)
goto security_error;
@@ -332,7 +334,7 @@
security_error:
kfree(key->description);
kmem_cache_free(key_jar, key);
- if (!not_in_quota) {
+ if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) {
spin_lock(&user->lock);
user->qnkeys--;
user->qnbytes -= quotalen;
@@ -345,7 +347,7 @@
no_memory_3:
kmem_cache_free(key_jar, key);
no_memory_2:
- if (!not_in_quota) {
+ if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) {
spin_lock(&user->lock);
user->qnkeys--;
user->qnbytes -= quotalen;
@@ -761,7 +763,7 @@
const char *description,
const void *payload,
size_t plen,
- int not_in_quota)
+ unsigned long flags)
{
struct key_type *ktype;
struct key *keyring, *key = NULL;
@@ -822,7 +824,7 @@
/* allocate a new key */
key = key_alloc(ktype, description, current->fsuid, current->fsgid,
- current, perm, not_in_quota);
+ current, perm, flags);
if (IS_ERR(key)) {
key_ref = ERR_PTR(PTR_ERR(key));
goto error_3;
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index ed71d86..d744585 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -102,7 +102,7 @@
/* create or update the requested key and add it to the target
* keyring */
key_ref = key_create_or_update(keyring_ref, type, description,
- payload, plen, 0);
+ payload, plen, KEY_ALLOC_IN_QUOTA);
if (!IS_ERR(key_ref)) {
ret = key_ref_to_ptr(key_ref)->serial;
key_ref_put(key_ref);
@@ -184,7 +184,8 @@
/* do the search */
key = request_key_and_link(ktype, description, callout_info,
- key_ref_to_ptr(dest_ref));
+ key_ref_to_ptr(dest_ref),
+ KEY_ALLOC_IN_QUOTA);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
goto error5;
diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index 1357207..6c282bd 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -240,7 +240,7 @@
* allocate a keyring and link into the destination keyring
*/
struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid,
- struct task_struct *ctx, int not_in_quota,
+ struct task_struct *ctx, unsigned long flags,
struct key *dest)
{
struct key *keyring;
@@ -249,7 +249,7 @@
keyring = key_alloc(&key_type_keyring, description,
uid, gid, ctx,
(KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL,
- not_in_quota);
+ flags);
if (!IS_ERR(keyring)) {
ret = key_instantiate_and_link(keyring, NULL, 0, dest, NULL);
diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index 4d9825f..32150cf 100644
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -77,7 +77,8 @@
/* concoct a default session keyring */
sprintf(buf, "_uid_ses.%u", user->uid);
- session_keyring = keyring_alloc(buf, user->uid, (gid_t) -1, ctx, 0, NULL);
+ session_keyring = keyring_alloc(buf, user->uid, (gid_t) -1, ctx,
+ KEY_ALLOC_IN_QUOTA, NULL);
if (IS_ERR(session_keyring)) {
ret = PTR_ERR(session_keyring);
goto error;
@@ -87,8 +88,8 @@
* keyring */
sprintf(buf, "_uid.%u", user->uid);
- uid_keyring = keyring_alloc(buf, user->uid, (gid_t) -1, ctx, 0,
- session_keyring);
+ uid_keyring = keyring_alloc(buf, user->uid, (gid_t) -1, ctx,
+ KEY_ALLOC_IN_QUOTA, session_keyring);
if (IS_ERR(uid_keyring)) {
key_put(session_keyring);
ret = PTR_ERR(uid_keyring);
@@ -144,7 +145,8 @@
sprintf(buf, "_tid.%u", tsk->pid);
- keyring = keyring_alloc(buf, tsk->uid, tsk->gid, tsk, 1, NULL);
+ keyring = keyring_alloc(buf, tsk->uid, tsk->gid, tsk,
+ KEY_ALLOC_QUOTA_OVERRUN, NULL);
if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
goto error;
@@ -178,7 +180,8 @@
if (!tsk->signal->process_keyring) {
sprintf(buf, "_pid.%u", tsk->tgid);
- keyring = keyring_alloc(buf, tsk->uid, tsk->gid, tsk, 1, NULL);
+ keyring = keyring_alloc(buf, tsk->uid, tsk->gid, tsk,
+ KEY_ALLOC_QUOTA_OVERRUN, NULL);
if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
goto error;
@@ -209,6 +212,7 @@
static int install_session_keyring(struct task_struct *tsk,
struct key *keyring)
{
+ unsigned long flags;
struct key *old;
char buf[20];
@@ -218,7 +222,12 @@
if (!keyring) {
sprintf(buf, "_ses.%u", tsk->tgid);
- keyring = keyring_alloc(buf, tsk->uid, tsk->gid, tsk, 1, NULL);
+ flags = KEY_ALLOC_QUOTA_OVERRUN;
+ if (tsk->signal->session_keyring)
+ flags = KEY_ALLOC_IN_QUOTA;
+
+ keyring = keyring_alloc(buf, tsk->uid, tsk->gid, tsk,
+ flags, NULL);
if (IS_ERR(keyring))
return PTR_ERR(keyring);
}
@@ -728,7 +737,8 @@
keyring = find_keyring_by_name(name, 0);
if (PTR_ERR(keyring) == -ENOKEY) {
/* not found - try and create a new one */
- keyring = keyring_alloc(name, tsk->uid, tsk->gid, tsk, 0, NULL);
+ keyring = keyring_alloc(name, tsk->uid, tsk->gid, tsk,
+ KEY_ALLOC_IN_QUOTA, NULL);
if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
goto error2;
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index eab66a0..58d1efd 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -48,8 +48,8 @@
/* allocate a new session keyring */
sprintf(desc, "_req.%u", key->serial);
- keyring = keyring_alloc(desc, current->fsuid, current->fsgid,
- current, 1, NULL);
+ keyring = keyring_alloc(desc, current->fsuid, current->fsgid, current,
+ KEY_ALLOC_QUOTA_OVERRUN, NULL);
if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
goto error_alloc;
@@ -126,7 +126,8 @@
*/
static struct key *__request_key_construction(struct key_type *type,
const char *description,
- const char *callout_info)
+ const char *callout_info,
+ unsigned long flags)
{
request_key_actor_t actor;
struct key_construction cons;
@@ -134,12 +135,12 @@
struct key *key, *authkey;
int ret, negated;
- kenter("%s,%s,%s", type->name, description, callout_info);
+ kenter("%s,%s,%s,%lx", type->name, description, callout_info, flags);
/* create a key and add it to the queue */
key = key_alloc(type, description,
- current->fsuid, current->fsgid,
- current, KEY_POS_ALL, 0);
+ current->fsuid, current->fsgid, current, KEY_POS_ALL,
+ flags);
if (IS_ERR(key))
goto alloc_failed;
@@ -258,15 +259,16 @@
static struct key *request_key_construction(struct key_type *type,
const char *description,
struct key_user *user,
- const char *callout_info)
+ const char *callout_info,
+ unsigned long flags)
{
struct key_construction *pcons;
struct key *key, *ckey;
DECLARE_WAITQUEUE(myself, current);
- kenter("%s,%s,{%d},%s",
- type->name, description, user->uid, callout_info);
+ kenter("%s,%s,{%d},%s,%lx",
+ type->name, description, user->uid, callout_info, flags);
/* see if there's such a key under construction already */
down_write(&key_construction_sem);
@@ -282,7 +284,8 @@
}
/* see about getting userspace to construct the key */
- key = __request_key_construction(type, description, callout_info);
+ key = __request_key_construction(type, description, callout_info,
+ flags);
error:
kleave(" = %p", key);
return key;
@@ -389,14 +392,15 @@
struct key *request_key_and_link(struct key_type *type,
const char *description,
const char *callout_info,
- struct key *dest_keyring)
+ struct key *dest_keyring,
+ unsigned long flags)
{
struct key_user *user;
struct key *key;
key_ref_t key_ref;
- kenter("%s,%s,%s,%p",
- type->name, description, callout_info, dest_keyring);
+ kenter("%s,%s,%s,%p,%lx",
+ type->name, description, callout_info, dest_keyring, flags);
/* search all the process keyrings for a key */
key_ref = search_process_keyrings(type, description, type->match,
@@ -429,7 +433,8 @@
/* ask userspace (returns NULL if it waited on a key
* being constructed) */
key = request_key_construction(type, description,
- user, callout_info);
+ user, callout_info,
+ flags);
if (key)
break;
@@ -485,7 +490,8 @@
const char *description,
const char *callout_info)
{
- return request_key_and_link(type, description, callout_info, NULL);
+ return request_key_and_link(type, description, callout_info, NULL,
+ KEY_ALLOC_IN_QUOTA);
} /* end request_key() */
diff --git a/security/keys/request_key_auth.c b/security/keys/request_key_auth.c
index cb9817c..cbf58a9 100644
--- a/security/keys/request_key_auth.c
+++ b/security/keys/request_key_auth.c
@@ -187,7 +187,7 @@
authkey = key_alloc(&key_type_request_key_auth, desc,
current->fsuid, current->fsgid, current,
KEY_POS_VIEW | KEY_POS_READ | KEY_POS_SEARCH |
- KEY_USR_VIEW, 1);
+ KEY_USR_VIEW, KEY_ALLOC_NOT_IN_QUOTA);
if (IS_ERR(authkey)) {
ret = PTR_ERR(authkey);
goto error_alloc;