/*
* RSAVP1() function [RFC3447 sec 5.2.2]
*/
static int RSAVP1(const struct public_key *key, MPI s, MPI *_m)
{
MPI m;
int ret;
/* (1) Validate 0 <= s < n */
if (mpi_cmp_ui(s, 0) < 0) {
kleave(" = -EBADMSG [s < 0]");
return -EBADMSG;
}
if (mpi_cmp(s, key->rsa.n) >= 0) {
kleave(" = -EBADMSG [s >= n]");
return -EBADMSG;
}
m = mpi_alloc(0);
if (!m)
return -ENOMEM;
/* (2) m = s^e mod n */
ret = mpi_powm(m, s, key->rsa.e, key->rsa.n);
if (ret < 0) {
mpi_free(m);
return ret;
}
*_m = m;
return 0;
}
/*
* allocate a new key in under-construction state and attempt to link it in to
* the requested place
* - may return a key that's already under construction instead
*/
static int construct_alloc_key(struct key_type *type,
const char *description,
struct key *dest_keyring,
unsigned long flags,
struct key_user *user,
struct key **_key)
{
const struct cred *cred = current_cred();
struct key *key;
key_ref_t key_ref;
kenter("%s,%s,,,", type->name, description);
mutex_lock(&user->cons_lock);
key = key_alloc(type, description, cred->fsuid, cred->fsgid, cred,
KEY_POS_ALL, flags);
if (IS_ERR(key))
goto alloc_failed;
set_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags);
down_write(&dest_keyring->sem);
/* attach the key to the destination keyring under lock, but we do need
* to do another check just in case someone beat us to it whilst we
* waited for locks */
mutex_lock(&key_construction_mutex);
key_ref = search_process_keyrings(type, description, type->match, cred);
if (!IS_ERR(key_ref))
goto key_already_present;
__key_link(dest_keyring, key);
mutex_unlock(&key_construction_mutex);
up_write(&dest_keyring->sem);
mutex_unlock(&user->cons_lock);
*_key = key;
kleave(" = 0 [%d]", key_serial(key));
return 0;
key_already_present:
mutex_unlock(&key_construction_mutex);
if (dest_keyring)
up_write(&dest_keyring->sem);
mutex_unlock(&user->cons_lock);
key_put(key);
*_key = key = key_ref_to_ptr(key_ref);
kleave(" = -EINPROGRESS [%d]", key_serial(key));
return -EINPROGRESS;
alloc_failed:
mutex_unlock(&user->cons_lock);
*_key = NULL;
kleave(" = %ld", PTR_ERR(key));
return PTR_ERR(key);
}
/*
* Commence key construction.
*/
static struct key *construct_key_and_link(struct keyring_search_context *ctx,
const char *callout_info,
size_t callout_len,
void *aux,
struct key *dest_keyring,
unsigned long flags)
{
struct key_user *user;
struct key *key;
int ret;
kenter("");
if (ctx->index_key.type == &key_type_keyring)
return ERR_PTR(-EPERM);
user = key_user_lookup(current_fsuid());
if (!user)
return ERR_PTR(-ENOMEM);
construct_get_dest_keyring(&dest_keyring);
ret = construct_alloc_key(ctx, dest_keyring, flags, user, &key);
key_user_put(user);
if (ret == 0) {
ret = construct_key(key, callout_info, callout_len, aux,
dest_keyring);
if (ret < 0) {
kdebug("cons failed");
goto construction_failed;
}
} else if (ret == -EINPROGRESS) {
ret = 0;
} else {
goto couldnt_alloc_key;
}
key_put(dest_keyring);
kleave(" = key %d", key_serial(key));
return key;
construction_failed:
key_negate_and_link(key, key_negative_timeout, NULL, NULL);
key_put(key);
couldnt_alloc_key:
key_put(dest_keyring);
kleave(" = %d", ret);
return ERR_PTR(ret);
}
/*
* Perform the verification step [RFC3447 sec 8.2.2].
*/
static int RSA_verify_signature(const struct public_key *key,
const struct public_key_signature *sig)
{
size_t tsize;
int ret;
/* Variables as per RFC3447 sec 8.2.2 */
const u8 *H = sig->digest;
u8 *EM = NULL;
MPI m = NULL;
size_t k;
kenter("");
if (!RSA_ASN1_templates[sig->pkey_hash_algo].data)
return -ENOTSUPP;
/* (1) Check the signature size against the public key modulus size */
k = mpi_get_nbits(key->rsa.n);
tsize = mpi_get_nbits(sig->rsa.s);
/* According to RFC 4880 sec 3.2, length of MPI is computed starting
* from most significant bit. So the RFC 3447 sec 8.2.2 size check
* must be relaxed to conform with shorter signatures - so we fail here
* only if signature length is longer than modulus size.
*/
pr_devel("step 1: k=%zu size(S)=%zu\n", k, tsize);
if (k < tsize) {
ret = -EBADMSG;
goto error;
}
/* Round up and convert to octets */
k = (k + 7) / 8;
/* (2b) Apply the RSAVP1 verification primitive to the public key */
ret = RSAVP1(key, sig->rsa.s, &m);
if (ret < 0)
goto error;
/* (2c) Convert the message representative (m) to an encoded message
* (EM) of length k octets.
*
* NOTE! The leading zero byte is suppressed by MPI, so we pass a
* pointer to the _preceding_ byte to RSA_verify()!
*/
ret = RSA_I2OSP(m, k, &EM);
if (ret < 0)
goto error;
ret = RSA_verify(H, EM - 1, k, sig->digest_size,
RSA_ASN1_templates[sig->pkey_hash_algo].data,
RSA_ASN1_templates[sig->pkey_hash_algo].size);
error:
kfree(EM);
mpi_free(m);
kleave(" = %d", ret);
return ret;
}
/*
* connection-level Rx packet processor
*/
static int rxrpc_process_event(struct rxrpc_connection *conn,
struct sk_buff *skb,
u32 *_abort_code)
{
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
__be32 wtmp;
u32 abort_code;
int loop, ret;
if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
kleave(" = -ECONNABORTED [%u]", conn->state);
return -ECONNABORTED;
}
_enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial);
switch (sp->hdr.type) {
case RXRPC_PACKET_TYPE_ABORT:
if (skb_copy_bits(skb, 0, &wtmp, sizeof(wtmp)) < 0)
return -EPROTO;
abort_code = ntohl(wtmp);
_proto("Rx ABORT %%%u { ac=%d }", sp->hdr.serial, abort_code);
conn->state = RXRPC_CONN_REMOTELY_ABORTED;
rxrpc_abort_calls(conn, RXRPC_CALL_REMOTELY_ABORTED,
abort_code);
return -ECONNABORTED;
case RXRPC_PACKET_TYPE_CHALLENGE:
return conn->security->respond_to_challenge(conn, skb,
_abort_code);
case RXRPC_PACKET_TYPE_RESPONSE:
ret = conn->security->verify_response(conn, skb, _abort_code);
if (ret < 0)
return ret;
ret = conn->security->init_connection_security(conn);
if (ret < 0)
return ret;
conn->security->prime_packet_security(conn);
read_lock_bh(&conn->lock);
spin_lock(&conn->state_lock);
if (conn->state == RXRPC_CONN_SERVER_CHALLENGING) {
conn->state = RXRPC_CONN_SERVER;
for (loop = 0; loop < RXRPC_MAXCALLS; loop++)
rxrpc_call_is_secure(conn->channels[loop]);
}
spin_unlock(&conn->state_lock);
read_unlock_bh(&conn->lock);
return 0;
default:
_leave(" = -EPROTO [%u]", sp->hdr.type);
return -EPROTO;
}
}
/*
* commence key construction
*/
static struct key *construct_key_and_link(struct key_type *type,
const char *description,
const char *callout_info,
size_t callout_len,
void *aux,
struct key *dest_keyring,
unsigned long flags)
{
struct key_user *user;
struct key *key;
int ret;
kenter("");
user = key_user_lookup(current_fsuid(), current_user_ns());
if (!user)
return ERR_PTR(-ENOMEM);
construct_get_dest_keyring(&dest_keyring);
ret = construct_alloc_key(type, description, dest_keyring, flags, user,
&key);
key_user_put(user);
if (ret == 0) {
ret = construct_key(key, callout_info, callout_len, aux,
dest_keyring);
if (ret < 0) {
kdebug("cons failed");
goto construction_failed;
}
}
key_put(dest_keyring);
kleave(" = key %d", key_serial(key));
return key;
construction_failed:
key_negate_and_link(key, key_negative_timeout, NULL, NULL);
key_put(key);
key_put(dest_keyring);
kleave(" = %d", ret);
return ERR_PTR(ret);
}
/*
* create a session keyring to be for the invokation of /sbin/request-key and
* stick an authorisation token in it
*/
struct key *request_key_auth_new(struct key *target, struct key **_rkakey)
{
struct key *keyring, *rkakey = NULL;
char desc[20];
int ret;
kenter("%d,", target->serial);
/* allocate a new session keyring */
sprintf(desc, "_req.%u", target->serial);
keyring = keyring_alloc(desc, current->fsuid, current->fsgid, 1, NULL);
if (IS_ERR(keyring)) {
kleave("= %ld", PTR_ERR(keyring));
return keyring;
}
/* allocate the auth key */
sprintf(desc, "%x", target->serial);
rkakey = key_alloc(&key_type_request_key_auth, desc,
current->fsuid, current->fsgid,
KEY_USR_VIEW, 1);
if (IS_ERR(rkakey)) {
key_put(keyring);
kleave("= %ld", PTR_ERR(rkakey));
return rkakey;
}
/* construct and attach to the keyring */
ret = key_instantiate_and_link(rkakey, target, 0, keyring, NULL);
if (ret < 0) {
key_revoke(rkakey);
key_put(rkakey);
key_put(keyring);
kleave("= %d", ret);
return ERR_PTR(ret);
}
*_rkakey = rkakey;
kleave(" = {%d} ({%d})", keyring->serial, rkakey->serial);
return keyring;
} /* end request_key_auth_new() */
/*
* handle mountpoint expiry timer going off
*/
static void afs_mntpt_expiry_timed_out(struct afs_timer *timer)
{
kenter("");
mark_mounts_for_expiry(&afs_vfsmounts);
afs_kafstimod_add_timer(&afs_mntpt_expiry_timer,
afs_mntpt_expiry_timeout * HZ);
kleave("");
} /* end afs_mntpt_expiry_timed_out() */
/*
* Garbage collect pointers from a keyring.
*
* Not called with any locks held. The keyring's key struct will not be
* deallocated under us as only our caller may deallocate it.
*/
static void key_gc_keyring(struct key *keyring, time_t limit)
{
struct keyring_list *klist;
struct key *key;
int loop;
kenter("%x", key_serial(keyring));
if (test_bit(KEY_FLAG_REVOKED, &keyring->flags))
goto dont_gc;
/* scan the keyring looking for dead keys */
rcu_read_lock();
klist = rcu_dereference(keyring->payload.subscriptions);
if (!klist)
goto unlock_dont_gc;
loop = klist->nkeys;
smp_rmb();
for (loop--; loop >= 0; loop--) {
key = klist->keys[loop];
if (test_bit(KEY_FLAG_DEAD, &key->flags) ||
(key->expiry > 0 && key->expiry <= limit))
goto do_gc;
}
unlock_dont_gc:
rcu_read_unlock();
dont_gc:
kleave(" [no gc]");
return;
do_gc:
rcu_read_unlock();
keyring_gc(keyring, limit);
kleave(" [gc]");
}
/*
* link a key to the appropriate destination keyring
* - the caller must hold a write lock on the destination keyring
*/
static void construct_key_make_link(struct key *key, struct key *dest_keyring)
{
struct task_struct *tsk = current;
struct key *drop = NULL;
kenter("{%d},%p", key->serial, dest_keyring);
/* find the appropriate keyring */
if (!dest_keyring) {
switch (tsk->jit_keyring) {
case KEY_REQKEY_DEFL_DEFAULT:
case KEY_REQKEY_DEFL_THREAD_KEYRING:
dest_keyring = tsk->thread_keyring;
if (dest_keyring)
break;
case KEY_REQKEY_DEFL_PROCESS_KEYRING:
dest_keyring = tsk->signal->process_keyring;
if (dest_keyring)
break;
case KEY_REQKEY_DEFL_SESSION_KEYRING:
rcu_read_lock();
dest_keyring = key_get(
rcu_dereference(tsk->signal->session_keyring));
rcu_read_unlock();
drop = dest_keyring;
if (dest_keyring)
break;
case KEY_REQKEY_DEFL_USER_SESSION_KEYRING:
dest_keyring = tsk->user->session_keyring;
break;
case KEY_REQKEY_DEFL_USER_KEYRING:
dest_keyring = tsk->user->uid_keyring;
break;
case KEY_REQKEY_DEFL_GROUP_KEYRING:
default:
BUG();
}
}
/* and attach the key to it */
__key_link(dest_keyring, key);
key_put(drop);
kleave("");
}
/**
* request_key_and_link - Request a key and cache it in a keyring.
* @type: The type of key we want.
* @description: The searchable description of the key.
* @callout_info: The data to pass to the instantiation upcall (or NULL).
* @callout_len: The length of callout_info.
* @aux: Auxiliary data for the upcall.
* @dest_keyring: Where to cache the key.
* @flags: Flags to key_alloc().
*
* A key matching the specified criteria is searched for in the process's
* keyrings and returned with its usage count incremented if found. Otherwise,
* if callout_info is not NULL, a key will be allocated and some service
* (probably in userspace) will be asked to instantiate it.
*
* If successfully found or created, the key will be linked to the destination
* keyring if one is provided.
*
* Returns a pointer to the key if successful; -EACCES, -ENOKEY, -EKEYREVOKED
* or -EKEYEXPIRED if an inaccessible, negative, revoked or expired key was
* found; -ENOKEY if no key was found and no @callout_info was given; -EDQUOT
* if insufficient key quota was available to create a new key; or -ENOMEM if
* insufficient memory was available.
*
* If the returned key was created, then it may still be under construction,
* and wait_for_key_construction() should be used to wait for that to complete.
*/
struct key *request_key_and_link(struct key_type *type,
const char *description,
const void *callout_info,
size_t callout_len,
void *aux,
struct key *dest_keyring,
unsigned long flags)
{
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,
dest_keyring, flags);
/* search all the process keyrings for a key */
key_ref = search_process_keyrings(type, description, type->match, cred);
if (!IS_ERR(key_ref)) {
key = key_ref_to_ptr(key_ref);
if (dest_keyring) {
construct_get_dest_keyring(&dest_keyring);
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);
} else {
/* the search failed, but the keyrings were searchable, so we
* should consult userspace if we can */
key = ERR_PTR(-ENOKEY);
if (!callout_info)
goto error;
key = construct_key_and_link(type, description, callout_info,
callout_len, aux, dest_keyring,
flags);
}
error:
kleave(" = %p", key);
return key;
}
/*
* Garbage collect pointers from a keyring.
*
* Not called with any locks held. The keyring's key struct will not be
* deallocated under us as only our caller may deallocate it.
*/
static void key_gc_keyring(struct key *keyring, time_t limit)
{
struct keyring_list *klist;
int loop;
kenter("%x", key_serial(keyring));
if (keyring->flags & ((1 << KEY_FLAG_INVALIDATED) |
(1 << KEY_FLAG_REVOKED)))
goto dont_gc;
/* scan the keyring looking for dead keys */
rcu_read_lock();
klist = rcu_dereference(keyring->payload.subscriptions);
if (!klist)
goto unlock_dont_gc;
loop = klist->nkeys;
smp_rmb();
for (loop--; loop >= 0; loop--) {
struct key *key = rcu_dereference(klist->keys[loop]);
if (key_is_dead(key, limit))
goto do_gc;
}
unlock_dont_gc:
rcu_read_unlock();
dont_gc:
kleave(" [no gc]");
return;
do_gc:
rcu_read_unlock();
keyring_gc(keyring, limit);
kleave(" [gc]");
}
/*
* Instantiate a PKCS#7 wrapped and validated key.
*/
int pkcs7_instantiate(struct key *key, struct key_preparsed_payload *prep)
{
struct pkcs7_message *pkcs7;
const void *data, *saved_prep_data;
size_t datalen, saved_prep_datalen;
bool trusted;
int ret;
kenter("");
saved_prep_data = prep->data;
saved_prep_datalen = prep->datalen;
pkcs7 = pkcs7_parse_message(saved_prep_data, saved_prep_datalen);
if (IS_ERR(pkcs7)) {
ret = PTR_ERR(pkcs7);
goto error;
}
ret = pkcs7_verify(pkcs7);
if (ret < 0)
goto error_free;
ret = pkcs7_validate_trust(pkcs7, system_trusted_keyring, &trusted);
if (ret < 0)
goto error_free;
if (!trusted)
pr_warn("PKCS#7 message doesn't chain back to a trusted key\n");
ret = pkcs7_get_content_data(pkcs7, &data, &datalen, false);
if (ret < 0)
goto error_free;
prep->data = data;
prep->datalen = datalen;
ret = user_instantiate(key, prep);
prep->data = saved_prep_data;
prep->datalen = saved_prep_datalen;
error_free:
pkcs7_free_message(pkcs7);
error:
kleave(" = %d", ret);
return ret;
}
/*
* Call out to userspace for key construction.
*
* Program failure is ignored in favour of key status.
*/
static int construct_key(struct key *key, const void *callout_info,
size_t callout_len, void *aux,
struct key *dest_keyring)
{
struct key_construction *cons;
request_key_actor_t actor;
struct key *authkey;
int ret;
kenter("%d,%p,%zu,%p", key->serial, callout_info, callout_len, aux);
cons = kmalloc(sizeof(*cons), GFP_KERNEL);
if (!cons)
return -ENOMEM;
/* allocate an authorisation key */
authkey = request_key_auth_new(key, callout_info, callout_len,
dest_keyring);
if (IS_ERR(authkey)) {
kfree(cons);
ret = PTR_ERR(authkey);
authkey = NULL;
} else {
cons->authkey = key_get(authkey);
cons->key = key_get(key);
/* make the call */
actor = call_sbin_request_key;
if (key->type->request_key)
actor = key->type->request_key;
ret = actor(cons, "create", aux);
/* check that the actor called complete_request_key() prior to
* returning an error */
WARN_ON(ret < 0 &&
!test_bit(KEY_FLAG_REVOKED, &authkey->flags));
key_put(authkey);
}
kleave(" = %d", ret);
return ret;
}
/*
* Reap keys of dead type.
*
* We use three flags to make sure we see three complete cycles of the garbage
* collector: the first to mark keys of that type as being dead, the second to
* collect dead links and the third to clean up the dead keys. We have to be
* careful as there may already be a cycle in progress.
*
* The caller must be holding key_types_sem.
*/
void key_gc_keytype(struct key_type *ktype)
{
kenter("%s", ktype->name);
key_gc_dead_keytype = ktype;
set_bit(KEY_GC_REAPING_KEYTYPE, &key_gc_flags);
smp_mb();
set_bit(KEY_GC_REAP_KEYTYPE, &key_gc_flags);
kdebug("schedule");
schedule_work(&key_gc_work);
kdebug("sleep");
wait_on_bit(&key_gc_flags, KEY_GC_REAPING_KEYTYPE, key_gc_wait_bit,
TASK_UNINTERRUPTIBLE);
key_gc_dead_keytype = NULL;
kleave("");
}
/*
* request a key
* - search the process's keyrings
* - check the list of keys being created or updated
* - call out to userspace for a key if supplementary info was provided
* - cache the key in an appropriate keyring
*/
struct key *request_key_and_link(struct key_type *type,
const char *description,
const char *callout_info,
void *aux,
struct key *dest_keyring,
unsigned long flags)
{
struct key *key;
key_ref_t key_ref;
kenter("%s,%s,%s,%p,%p,%lx",
type->name, description, callout_info, aux,
dest_keyring, flags);
/* search all the process keyrings for a key */
key_ref = search_process_keyrings(type, description, type->match,
current);
if (!IS_ERR(key_ref)) {
key = key_ref_to_ptr(key_ref);
} else if (PTR_ERR(key_ref) != -EAGAIN) {
key = ERR_PTR(PTR_ERR(key_ref));
} else {
/* the search failed, but the keyrings were searchable, so we
* should consult userspace if we can */
key = ERR_PTR(-ENOKEY);
if (!callout_info)
goto error;
key = construct_key_and_link(type, description, callout_info,
aux, dest_keyring, flags);
}
error:
kleave(" = %p", key);
return key;
}
/*
* follow a link from a mountpoint directory, thus causing it to be mounted
*/
static void *afs_mntpt_follow_link(struct dentry *dentry, struct nameidata *nd)
{
struct vfsmount *newmnt;
struct dentry *old_dentry;
int err;
kenter("%p{%s},{%s:%p{%s}}",
dentry,
dentry->d_name.name,
nd->mnt->mnt_devname,
dentry,
nd->dentry->d_name.name);
newmnt = afs_mntpt_do_automount(dentry);
if (IS_ERR(newmnt)) {
path_release(nd);
return (void *)newmnt;
}
old_dentry = nd->dentry;
nd->dentry = dentry;
err = do_add_mount(newmnt, nd, 0, &afs_vfsmounts);
nd->dentry = old_dentry;
path_release(nd);
if (!err) {
mntget(newmnt);
nd->mnt = newmnt;
dget(newmnt->mnt_root);
nd->dentry = newmnt->mnt_root;
}
kleave(" = %d", err);
return ERR_PTR(err);
} /* end afs_mntpt_follow_link() */
/*
* Perform the RSA signature verification.
* @H: Value of hash of data and metadata
* @EM: The computed signature value
* @k: The size of EM (EM[0] is an invalid location but should hold 0x00)
* @hash_size: The size of H
* @asn1_template: The DigestInfo ASN.1 template
* @asn1_size: Size of asm1_template[]
*/
static int RSA_verify(const u8 *H, const u8 *EM, size_t k, size_t hash_size,
const u8 *asn1_template, size_t asn1_size)
{
unsigned PS_end, T_offset, i;
kenter(",,%zu,%zu,%zu", k, hash_size, asn1_size);
if (k < 2 + 1 + asn1_size + hash_size)
return -EBADMSG;
/* Decode the EMSA-PKCS1-v1_5 */
if (EM[1] != 0x01) {
kleave(" = -EBADMSG [EM[1] == %02u]", EM[1]);
return -EBADMSG;
}
T_offset = k - (asn1_size + hash_size);
PS_end = T_offset - 1;
if (EM[PS_end] != 0x00) {
kleave(" = -EBADMSG [EM[T-1] == %02u]", EM[PS_end]);
return -EBADMSG;
}
for (i = 2; i < PS_end; i++) {
if (EM[i] != 0xff) {
kleave(" = -EBADMSG [EM[PS%x] == %02u]", i - 2, EM[i]);
return -EBADMSG;
}
}
if (crypto_memneq(asn1_template, EM + T_offset, asn1_size) != 0) {
kleave(" = -EBADMSG [EM[T] ASN.1 mismatch]");
return -EBADMSG;
}
if (crypto_memneq(H, EM + T_offset + asn1_size, hash_size) != 0) {
kleave(" = -EKEYREJECTED [EM[T] hash mismatch]");
return -EKEYREJECTED;
}
kleave(" = 0");
return 0;
}
/*
* Allocate a new key in under-construction state and attempt to link it in to
* the requested keyring.
*
* May return a key that's already under construction instead if there was a
* race between two thread calling request_key().
*/
static int construct_alloc_key(struct key_type *type,
const char *description,
struct key *dest_keyring,
unsigned long flags,
struct key_user *user,
struct key **_key)
{
const struct cred *cred = current_cred();
unsigned long prealloc;
struct key *key;
key_ref_t key_ref;
int ret;
kenter("%s,%s,,,", type->name, description);
*_key = NULL;
mutex_lock(&user->cons_lock);
key = key_alloc(type, description, cred->fsuid, cred->fsgid, cred,
KEY_POS_ALL, flags);
if (IS_ERR(key))
goto alloc_failed;
set_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags);
if (dest_keyring) {
ret = __key_link_begin(dest_keyring, type, description,
&prealloc);
if (ret < 0)
goto link_prealloc_failed;
}
/* attach the key to the destination keyring under lock, but we do need
* to do another check just in case someone beat us to it whilst we
* waited for locks */
mutex_lock(&key_construction_mutex);
key_ref = search_process_keyrings(type, description, type->match, cred);
if (!IS_ERR(key_ref))
goto key_already_present;
if (dest_keyring)
__key_link(dest_keyring, key, &prealloc);
mutex_unlock(&key_construction_mutex);
if (dest_keyring)
__key_link_end(dest_keyring, type, prealloc);
mutex_unlock(&user->cons_lock);
*_key = key;
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:
key_put(key);
mutex_unlock(&key_construction_mutex);
key = key_ref_to_ptr(key_ref);
if (dest_keyring) {
ret = __key_link_check_live_key(dest_keyring, key);
if (ret == 0)
__key_link(dest_keyring, key, &prealloc);
__key_link_end(dest_keyring, type, prealloc);
if (ret < 0)
goto link_check_failed;
}
mutex_unlock(&user->cons_lock);
*_key = key;
kleave(" = -EINPROGRESS [%d]", key_serial(key));
return -EINPROGRESS;
link_check_failed:
mutex_unlock(&user->cons_lock);
key_put(key);
kleave(" = %d [linkcheck]", ret);
return ret;
link_prealloc_failed:
mutex_unlock(&user->cons_lock);
kleave(" = %d [prelink]", ret);
return ret;
alloc_failed:
mutex_unlock(&user->cons_lock);
kleave(" = %ld", PTR_ERR(key));
return PTR_ERR(key);
}
/**
* dns_query - Query the DNS
* @type: Query type (or NULL for straight host->IP lookup)
* @name: Name to look up
* @namelen: Length of name
* @options: Request options (or NULL if no options)
* @_result: Where to place the returned data (or NULL)
* @_expiry: Where to store the result expiry time (or NULL)
*
* The data will be returned in the pointer at *result, if provided, and the
* caller is responsible for freeing it.
*
* The description should be of the form "[<query_type>:]<domain_name>", and
* the options need to be appropriate for the query type requested. If no
* query_type is given, then the query is a straight hostname to IP address
* lookup.
*
* The DNS resolution lookup is performed by upcalling to userspace by way of
* requesting a key of type dns_resolver.
*
* Returns the size of the result on success, -ve error code otherwise.
*/
int dns_query(const char *type, const char *name, size_t namelen,
const char *options, char **_result, time64_t *_expiry)
{
struct key *rkey;
struct user_key_payload *upayload;
const struct cred *saved_cred;
size_t typelen, desclen;
char *desc, *cp;
int ret, len;
kenter("%s,%*.*s,%zu,%s",
type, (int)namelen, (int)namelen, name, namelen, options);
if (!name || namelen == 0)
return -EINVAL;
/* construct the query key description as "[<type>:]<name>" */
typelen = 0;
desclen = 0;
if (type) {
typelen = strlen(type);
if (typelen < 1)
return -EINVAL;
desclen += typelen + 1;
}
if (!namelen)
namelen = strnlen(name, 256);
if (namelen < 3 || namelen > 255)
return -EINVAL;
desclen += namelen + 1;
desc = kmalloc(desclen, GFP_KERNEL);
if (!desc)
return -ENOMEM;
cp = desc;
if (type) {
memcpy(cp, type, typelen);
cp += typelen;
*cp++ = ':';
}
memcpy(cp, name, namelen);
cp += namelen;
*cp = '\0';
if (!options)
options = "";
kdebug("call request_key(,%s,%s)", desc, options);
/* make the upcall, using special credentials to prevent the use of
* add_key() to preinstall malicious redirections
*/
saved_cred = override_creds(dns_resolver_cache);
rkey = request_key(&key_type_dns_resolver, desc, options);
revert_creds(saved_cred);
kfree(desc);
if (IS_ERR(rkey)) {
ret = PTR_ERR(rkey);
goto out;
}
down_read(&rkey->sem);
set_bit(KEY_FLAG_ROOT_CAN_INVAL, &rkey->flags);
rkey->perm |= KEY_USR_VIEW;
ret = key_validate(rkey);
if (ret < 0)
goto put;
/* If the DNS server gave an error, return that to the caller */
ret = PTR_ERR(rkey->payload.data[dns_key_error]);
if (ret)
goto put;
upayload = user_key_payload_locked(rkey);
len = upayload->datalen;
if (_result) {
ret = -ENOMEM;
*_result = kmalloc(len + 1, GFP_KERNEL);
if (!*_result)
goto put;
memcpy(*_result, upayload->data, len);
(*_result)[len] = '\0';
}
if (_expiry)
*_expiry = rkey->expiry;
ret = len;
put:
up_read(&rkey->sem);
key_put(rkey);
out:
kleave(" = %d", ret);
return ret;
}
static void key_garbage_collector(struct work_struct *work)
{
struct rb_node *rb;
key_serial_t cursor;
struct key *key, *xkey;
time_t new_timer = LONG_MAX, limit, now;
now = current_kernel_time().tv_sec;
kenter("[%x,%ld]", key_gc_cursor, key_gc_new_timer - now);
if (test_and_set_bit(0, &key_gc_executing)) {
key_schedule_gc(current_kernel_time().tv_sec + 1);
kleave(" [busy; deferring]");
return;
}
limit = now;
if (limit > key_gc_delay)
limit -= key_gc_delay;
else
limit = key_gc_delay;
spin_lock(&key_serial_lock);
if (unlikely(RB_EMPTY_ROOT(&key_serial_tree))) {
spin_unlock(&key_serial_lock);
clear_bit(0, &key_gc_executing);
return;
}
cursor = key_gc_cursor;
if (cursor < 0)
cursor = 0;
if (cursor > 0)
new_timer = key_gc_new_timer;
else
key_gc_again = false;
/* find the first key above the cursor */
key = NULL;
rb = key_serial_tree.rb_node;
while (rb) {
xkey = rb_entry(rb, struct key, serial_node);
if (cursor < xkey->serial) {
key = xkey;
rb = rb->rb_left;
} else if (cursor > xkey->serial) {
rb = rb->rb_right;
} else {
rb = rb_next(rb);
if (!rb)
goto reached_the_end;
key = rb_entry(rb, struct key, serial_node);
break;
}
}
if (!key)
goto reached_the_end;
/* trawl through the keys looking for keyrings */
for (;;) {
if (key->expiry > limit && key->expiry < new_timer) {
kdebug("will expire %x in %ld",
key_serial(key), key->expiry - limit);
new_timer = key->expiry;
}
if (key->type == &key_type_keyring &&
key_gc_keyring(key, limit))
/* the gc had to release our lock so that the keyring
* could be modified, so we have to get it again */
goto gc_released_our_lock;
rb = rb_next(&key->serial_node);
if (!rb)
goto reached_the_end;
key = rb_entry(rb, struct key, serial_node);
}
gc_released_our_lock:
kdebug("gc_released_our_lock");
key_gc_new_timer = new_timer;
key_gc_again = true;
clear_bit(0, &key_gc_executing);
schedule_work(&key_gc_work);
kleave(" [continue]");
return;
/* when we reach the end of the run, we set the timer for the next one */
reached_the_end:
kdebug("reached_the_end");
spin_unlock(&key_serial_lock);
key_gc_new_timer = new_timer;
key_gc_cursor = 0;
clear_bit(0, &key_gc_executing);
if (key_gc_again) {
/* there may have been a key that expired whilst we were
* scanning, so if we discarded any links we should do another
* scan */
new_timer = now + 1;
key_schedule_gc(new_timer);
} else if (new_timer < LONG_MAX) {
new_timer += key_gc_delay;
key_schedule_gc(new_timer);
}
kleave(" [end]");
}
/*
* Install the user and user session keyrings for the current process's UID.
*/
int install_user_keyrings(void)
{
struct user_struct *user;
const struct cred *cred;
struct key *uid_keyring, *session_keyring;
char buf[20];
int ret;
cred = current_cred();
user = cred->user;
kenter("%p{%u}", user, user->uid);
if (user->uid_keyring && user->session_keyring) {
kleave(" = 0 [exist]");
return 0;
}
mutex_lock(&key_user_keyring_mutex);
ret = 0;
if (!user->uid_keyring) {
/* get the UID-specific keyring
* - there may be one in existence already as it may have been
* pinned by a session, but the user_struct pointing to it
* may have been destroyed by setuid */
sprintf(buf, "_uid.%u", user->uid);
uid_keyring = find_keyring_by_name(buf, true);
if (IS_ERR(uid_keyring)) {
uid_keyring = keyring_alloc(buf, user->uid, (gid_t) -1,
cred, KEY_ALLOC_IN_QUOTA,
NULL);
if (IS_ERR(uid_keyring)) {
ret = PTR_ERR(uid_keyring);
goto error;
}
}
/* get a default session keyring (which might also exist
* already) */
sprintf(buf, "_uid_ses.%u", user->uid);
session_keyring = find_keyring_by_name(buf, true);
if (IS_ERR(session_keyring)) {
session_keyring =
keyring_alloc(buf, user->uid, (gid_t) -1,
cred, KEY_ALLOC_IN_QUOTA, NULL);
if (IS_ERR(session_keyring)) {
ret = PTR_ERR(session_keyring);
goto error_release;
}
/* we install a link from the user session keyring to
* the user keyring */
ret = key_link(session_keyring, uid_keyring);
if (ret < 0)
goto error_release_both;
}
/* install the keyrings */
user->uid_keyring = uid_keyring;
user->session_keyring = session_keyring;
}
mutex_unlock(&key_user_keyring_mutex);
kleave(" = 0");
return 0;
error_release_both:
key_put(session_keyring);
error_release:
key_put(uid_keyring);
error:
mutex_unlock(&key_user_keyring_mutex);
kleave(" = %d", ret);
return ret;
}
/**
* Check the trust on one PKCS#7 SignedInfo block.
*/
static int pkcs7_validate_trust_one(struct pkcs7_message *pkcs7,
struct pkcs7_signed_info *sinfo,
struct key *trust_keyring)
{
struct public_key_signature *sig = sinfo->sig;
struct x509_certificate *x509, *last = NULL, *p;
struct key *key;
int ret;
kenter(",%u,", sinfo->index);
if (sinfo->unsupported_crypto) {
kleave(" = -ENOPKG [cached]");
return -ENOPKG;
}
for (x509 = sinfo->signer; x509; x509 = x509->signer) {
if (x509->seen) {
if (x509->verified)
goto verified;
kleave(" = -ENOKEY [cached]");
return -ENOKEY;
}
x509->seen = true;
/* Look to see if this certificate is present in the trusted
* keys.
*/
key = find_asymmetric_key(trust_keyring,
x509->id, x509->skid, false);
if (!IS_ERR(key)) {
/* One of the X.509 certificates in the PKCS#7 message
* is apparently the same as one we already trust.
* Verify that the trusted variant can also validate
* the signature on the descendant.
*/
pr_devel("sinfo %u: Cert %u as key %x\n",
sinfo->index, x509->index, key_serial(key));
goto matched;
}
if (key == ERR_PTR(-ENOMEM))
return -ENOMEM;
/* Self-signed certificates form roots of their own, and if we
* don't know them, then we can't accept them.
*/
if (x509->signer == x509) {
kleave(" = -ENOKEY [unknown self-signed]");
return -ENOKEY;
}
might_sleep();
last = x509;
sig = last->sig;
}
/* No match - see if the root certificate has a signer amongst the
* trusted keys.
*/
if (last && (last->sig->auth_ids[0] || last->sig->auth_ids[1])) {
key = find_asymmetric_key(trust_keyring,
last->sig->auth_ids[0],
last->sig->auth_ids[1],
false);
if (!IS_ERR(key)) {
x509 = last;
pr_devel("sinfo %u: Root cert %u signer is key %x\n",
sinfo->index, x509->index, key_serial(key));
goto matched;
}
if (PTR_ERR(key) != -ENOKEY)
return PTR_ERR(key);
}
/* As a last resort, see if we have a trusted public key that matches
* the signed info directly.
*/
key = find_asymmetric_key(trust_keyring,
sinfo->sig->auth_ids[0], NULL, false);
if (!IS_ERR(key)) {
pr_devel("sinfo %u: Direct signer is key %x\n",
sinfo->index, key_serial(key));
x509 = NULL;
goto matched;
}
if (PTR_ERR(key) != -ENOKEY)
return PTR_ERR(key);
kleave(" = -ENOKEY [no backref]");
return -ENOKEY;
matched:
ret = public_key_verify_signature(key->public_key, sig);
key_put(key);
if (ret < 0) {
if (ret == -ENOMEM)
return ret;
kleave(" = -EKEYREJECTED [verify %d]", ret);
return -EKEYREJECTED;
}
verified:
if (x509) {
x509->verified = true;
for (p = sinfo->signer; p != x509; p = p->signer)
p->verified = true;
}
kleave(" = 0");
return 0;
}
/*
* Get the appropriate destination keyring for the request.
*
* The keyring selected is returned with an extra reference upon it which the
* caller must release.
*/
static void construct_get_dest_keyring(struct key **_dest_keyring)
{
struct request_key_auth *rka;
const struct cred *cred = current_cred();
struct key *dest_keyring = *_dest_keyring, *authkey;
kenter("%p", dest_keyring);
/* find the appropriate keyring */
if (dest_keyring) {
/* the caller supplied one */
key_get(dest_keyring);
} else {
/* use a default keyring; falling through the cases until we
* find one that we actually have */
switch (cred->jit_keyring) {
case KEY_REQKEY_DEFL_DEFAULT:
case KEY_REQKEY_DEFL_REQUESTOR_KEYRING:
if (cred->request_key_auth) {
authkey = cred->request_key_auth;
down_read(&authkey->sem);
rka = authkey->payload.data;
if (!test_bit(KEY_FLAG_REVOKED,
&authkey->flags))
dest_keyring =
key_get(rka->dest_keyring);
up_read(&authkey->sem);
if (dest_keyring)
break;
}
case KEY_REQKEY_DEFL_THREAD_KEYRING:
dest_keyring = key_get(cred->thread_keyring);
if (dest_keyring)
break;
case KEY_REQKEY_DEFL_PROCESS_KEYRING:
dest_keyring = key_get(cred->tgcred->process_keyring);
if (dest_keyring)
break;
case KEY_REQKEY_DEFL_SESSION_KEYRING:
rcu_read_lock();
dest_keyring = key_get(
rcu_dereference(cred->tgcred->session_keyring));
rcu_read_unlock();
if (dest_keyring)
break;
case KEY_REQKEY_DEFL_USER_SESSION_KEYRING:
dest_keyring =
key_get(cred->user->session_keyring);
break;
case KEY_REQKEY_DEFL_USER_KEYRING:
dest_keyring = key_get(cred->user->uid_keyring);
break;
case KEY_REQKEY_DEFL_GROUP_KEYRING:
default:
BUG();
}
}
*_dest_keyring = dest_keyring;
kleave(" [dk %d]", key_serial(dest_keyring));
return;
}
/*
* create a vfsmount to be automounted
*/
static struct vfsmount *afs_mntpt_do_automount(struct dentry *mntpt)
{
struct afs_super_info *super;
struct vfsmount *mnt;
struct page *page = NULL;
size_t size;
char *buf, *devname = NULL, *options = NULL;
int ret;
kenter("{%s}", mntpt->d_name.name);
BUG_ON(!mntpt->d_inode);
ret = -EINVAL;
size = mntpt->d_inode->i_size;
if (size > PAGE_SIZE - 1)
goto error;
ret = -ENOMEM;
devname = (char *) get_zeroed_page(GFP_KERNEL);
if (!devname)
goto error;
options = (char *) get_zeroed_page(GFP_KERNEL);
if (!options)
goto error;
/* read the contents of the AFS special symlink */
page = read_mapping_page(mntpt->d_inode->i_mapping, 0, NULL);
if (IS_ERR(page)) {
ret = PTR_ERR(page);
goto error;
}
ret = -EIO;
wait_on_page_locked(page);
if (!PageUptodate(page) || PageError(page))
goto error;
buf = kmap(page);
memcpy(devname, buf, size);
kunmap(page);
page_cache_release(page);
page = NULL;
/* work out what options we want */
super = AFS_FS_S(mntpt->d_sb);
memcpy(options, "cell=", 5);
strcpy(options + 5, super->volume->cell->name);
if (super->volume->type == AFSVL_RWVOL)
strcat(options, ",rwpath");
/* try and do the mount */
kdebug("--- attempting mount %s -o %s ---", devname, options);
mnt = vfs_kern_mount(&afs_fs_type, 0, devname, options);
kdebug("--- mount result %p ---", mnt);
free_page((unsigned long) devname);
free_page((unsigned long) options);
kleave(" = %p", mnt);
return mnt;
error:
if (page)
page_cache_release(page);
if (devname)
free_page((unsigned long) devname);
if (options)
free_page((unsigned long) options);
kleave(" = %d", ret);
return ERR_PTR(ret);
} /* end afs_mntpt_do_automount() */
/**
* Check the trust on one PKCS#7 SignedInfo block.
*/
int pkcs7_validate_trust_one(struct pkcs7_message *pkcs7,
struct pkcs7_signed_info *sinfo,
struct key *trust_keyring)
{
struct public_key_signature *sig = &sinfo->sig;
struct x509_certificate *x509, *last = NULL, *p;
struct key *key;
bool trusted;
int ret;
kenter(",%u,", sinfo->index);
for (x509 = sinfo->signer; x509; x509 = x509->signer) {
if (x509->seen) {
if (x509->verified) {
trusted = x509->trusted;
goto verified;
}
kleave(" = -ENOKEY [cached]");
return -ENOKEY;
}
x509->seen = true;
/* Look to see if this certificate is present in the trusted
* keys.
*/
key = pkcs7_request_asymmetric_key(
trust_keyring,
x509->subject, strlen(x509->subject),
x509->fingerprint, strlen(x509->fingerprint));
if (!IS_ERR(key))
/* One of the X.509 certificates in the PKCS#7 message
* is apparently the same as one we already trust.
* Verify that the trusted variant can also validate
* the signature on the descendant.
*/
goto matched;
if (key == ERR_PTR(-ENOMEM))
return -ENOMEM;
/* Self-signed certificates form roots of their own, and if we
* don't know them, then we can't accept them.
*/
if (x509->next == x509) {
kleave(" = -ENOKEY [unknown self-signed]");
return -ENOKEY;
}
might_sleep();
last = x509;
sig = &last->sig;
}
/* No match - see if the root certificate has a signer amongst the
* trusted keys.
*/
if (!last || !last->issuer || !last->authority) {
kleave(" = -ENOKEY [no backref]");
return -ENOKEY;
}
key = pkcs7_request_asymmetric_key(
trust_keyring,
last->issuer, strlen(last->issuer),
last->authority, strlen(last->authority));
if (IS_ERR(key))
return PTR_ERR(key) == -ENOMEM ? -ENOMEM : -ENOKEY;
x509 = last;
matched:
ret = verify_signature(key, sig);
trusted = test_bit(KEY_FLAG_TRUSTED, &key->flags);
key_put(key);
if (ret < 0) {
if (ret == -ENOMEM)
return ret;
kleave(" = -EKEYREJECTED [verify %d]", ret);
return -EKEYREJECTED;
}
verified:
x509->verified = true;
for (p = sinfo->signer; p != x509; p = p->signer) {
p->verified = true;
p->trusted = trusted;
}
sinfo->trusted = trusted;
kleave(" = 0");
return 0;
}
int afs_rxfs_lookup(struct afs_server *server,
struct afs_vnode *dir,
const char *filename,
struct afs_vnode *vnode,
struct afs_volsync *volsync)
{
struct rxrpc_connection *conn;
struct rxrpc_call *call;
struct kvec piov[3];
size_t sent;
int ret;
u32 *bp, zero;
DECLARE_WAITQUEUE(myself, current);
kenter("%p,{%u,%u,%u},%s",
server, fid->vid, fid->vnode, fid->unique, filename);
/* get hold of the fileserver connection */
ret = afs_server_get_fsconn(server, &conn);
if (ret < 0)
goto out;
/* create a call through that connection */
ret = rxrpc_create_call(conn, NULL, NULL, afs_rxfs_aemap, &call);
if (ret < 0) {
printk("kAFS: Unable to create call: %d\n", ret);
goto out_put_conn;
}
call->app_opcode = FSLOOKUP;
/* we want to get event notifications from the call */
add_wait_queue(&call->waitq,&myself);
/* marshall the parameters */
bp = rxrpc_call_alloc_scratch(call, 20);
zero = 0;
piov[0].iov_len = 20;
piov[0].iov_base = bp;
piov[1].iov_len = strlen(filename);
piov[1].iov_base = (char *) filename;
piov[2].iov_len = (4 - (piov[1].iov_len & 3)) & 3;
piov[2].iov_base = &zero;
*bp++ = htonl(FSLOOKUP);
*bp++ = htonl(dirfid->vid);
*bp++ = htonl(dirfid->vnode);
*bp++ = htonl(dirfid->unique);
*bp++ = htonl(piov[1].iov_len);
/* send the parameters to the server */
ret = rxrpc_call_write_data(call, 3, piov, RXRPC_LAST_PACKET, GFP_NOFS,
0, &sent);
if (ret < 0)
goto abort;
/* wait for the reply to completely arrive */
bp = rxrpc_call_alloc_scratch(call, 220);
ret = rxrpc_call_read_data(call, bp, 220,
RXRPC_CALL_READ_BLOCK |
RXRPC_CALL_READ_ALL);
if (ret < 0) {
if (ret == -ECONNABORTED) {
ret = call->app_errno;
goto out_unwait;
}
goto abort;
}
/* unmarshall the reply */
fid->vid = ntohl(*bp++);
fid->vnode = ntohl(*bp++);
fid->unique = ntohl(*bp++);
vnode->status.if_version = ntohl(*bp++);
vnode->status.type = ntohl(*bp++);
vnode->status.nlink = ntohl(*bp++);
vnode->status.size = ntohl(*bp++);
vnode->status.version = ntohl(*bp++);
vnode->status.author = ntohl(*bp++);
vnode->status.owner = ntohl(*bp++);
vnode->status.caller_access = ntohl(*bp++);
vnode->status.anon_access = ntohl(*bp++);
vnode->status.mode = ntohl(*bp++);
vnode->status.parent.vid = dirfid->vid;
vnode->status.parent.vnode = ntohl(*bp++);
vnode->status.parent.unique = ntohl(*bp++);
bp++; /* seg size */
vnode->status.mtime_client = ntohl(*bp++);
vnode->status.mtime_server = ntohl(*bp++);
bp++; /* group */
bp++; /* sync counter */
vnode->status.version |= ((unsigned long long) ntohl(*bp++)) << 32;
bp++; /* spare2 */
bp++; /* spare3 */
bp++; /* spare4 */
dir->status.if_version = ntohl(*bp++);
dir->status.type = ntohl(*bp++);
dir->status.nlink = ntohl(*bp++);
dir->status.size = ntohl(*bp++);
dir->status.version = ntohl(*bp++);
dir->status.author = ntohl(*bp++);
dir->status.owner = ntohl(*bp++);
dir->status.caller_access = ntohl(*bp++);
dir->status.anon_access = ntohl(*bp++);
dir->status.mode = ntohl(*bp++);
dir->status.parent.vid = dirfid->vid;
dir->status.parent.vnode = ntohl(*bp++);
dir->status.parent.unique = ntohl(*bp++);
bp++; /* seg size */
dir->status.mtime_client = ntohl(*bp++);
dir->status.mtime_server = ntohl(*bp++);
bp++; /* group */
bp++; /* sync counter */
dir->status.version |= ((unsigned long long) ntohl(*bp++)) << 32;
bp++; /* spare2 */
bp++; /* spare3 */
bp++; /* spare4 */
callback->fid = *fid;
callback->version = ntohl(*bp++);
callback->expiry = ntohl(*bp++);
callback->type = ntohl(*bp++);
if (volsync) {
volsync->creation = ntohl(*bp++);
bp++; /* spare2 */
bp++; /* spare3 */
bp++; /* spare4 */
bp++; /* spare5 */
bp++; /* spare6 */
}
/* success */
ret = 0;
out_unwait:
set_current_state(TASK_RUNNING);
remove_wait_queue(&call->waitq, &myself);
rxrpc_put_call(call);
out_put_conn:
afs_server_release_fsconn(server, conn);
out:
kleave("");
return ret;
abort:
set_current_state(TASK_UNINTERRUPTIBLE);
rxrpc_call_abort(call, ret);
schedule();
goto out_unwait;
} /* end afs_rxfs_lookup() */
/*
* Garbage collector for unused keys.
*
* This is done in process context so that we don't have to disable interrupts
* all over the place. key_put() schedules this rather than trying to do the
* cleanup itself, which means key_put() doesn't have to sleep.
*/
static void key_garbage_collector(struct work_struct *work)
{
static LIST_HEAD(graveyard);
static u8 gc_state; /* Internal persistent state */
#define KEY_GC_REAP_AGAIN 0x01 /* - Need another cycle */
#define KEY_GC_REAPING_LINKS 0x02 /* - We need to reap links */
#define KEY_GC_SET_TIMER 0x04 /* - We need to restart the timer */
#define KEY_GC_REAPING_DEAD_1 0x10 /* - We need to mark dead keys */
#define KEY_GC_REAPING_DEAD_2 0x20 /* - We need to reap dead key links */
#define KEY_GC_REAPING_DEAD_3 0x40 /* - We need to reap dead keys */
#define KEY_GC_FOUND_DEAD_KEY 0x80 /* - We found at least one dead key */
struct rb_node *cursor;
struct key *key;
time_t new_timer, limit;
kenter("[%lx,%x]", key_gc_flags, gc_state);
limit = current_kernel_time().tv_sec;
if (limit > key_gc_delay)
limit -= key_gc_delay;
else
limit = key_gc_delay;
/* Work out what we're going to be doing in this pass */
gc_state &= KEY_GC_REAPING_DEAD_1 | KEY_GC_REAPING_DEAD_2;
gc_state <<= 1;
if (test_and_clear_bit(KEY_GC_KEY_EXPIRED, &key_gc_flags))
gc_state |= KEY_GC_REAPING_LINKS | KEY_GC_SET_TIMER;
if (test_and_clear_bit(KEY_GC_REAP_KEYTYPE, &key_gc_flags))
gc_state |= KEY_GC_REAPING_DEAD_1;
kdebug("new pass %x", gc_state);
new_timer = LONG_MAX;
/* As only this function is permitted to remove things from the key
* serial tree, if cursor is non-NULL then it will always point to a
* valid node in the tree - even if lock got dropped.
*/
spin_lock(&key_serial_lock);
cursor = rb_first(&key_serial_tree);
continue_scanning:
while (cursor) {
key = rb_entry(cursor, struct key, serial_node);
cursor = rb_next(cursor);
if (atomic_read(&key->usage) == 0)
goto found_unreferenced_key;
if (unlikely(gc_state & KEY_GC_REAPING_DEAD_1)) {
if (key->type == key_gc_dead_keytype) {
gc_state |= KEY_GC_FOUND_DEAD_KEY;
set_bit(KEY_FLAG_DEAD, &key->flags);
key->perm = 0;
goto skip_dead_key;
}
}
if (gc_state & KEY_GC_SET_TIMER) {
if (key->expiry > limit && key->expiry < new_timer) {
kdebug("will expire %x in %ld",
key_serial(key), key->expiry - limit);
new_timer = key->expiry;
}
}
if (unlikely(gc_state & KEY_GC_REAPING_DEAD_2))
if (key->type == key_gc_dead_keytype)
gc_state |= KEY_GC_FOUND_DEAD_KEY;
if ((gc_state & KEY_GC_REAPING_LINKS) ||
unlikely(gc_state & KEY_GC_REAPING_DEAD_2)) {
if (key->type == &key_type_keyring)
goto found_keyring;
}
if (unlikely(gc_state & KEY_GC_REAPING_DEAD_3))
if (key->type == key_gc_dead_keytype)
goto destroy_dead_key;
skip_dead_key:
if (spin_is_contended(&key_serial_lock) || need_resched())
goto contended;
}
contended:
spin_unlock(&key_serial_lock);
maybe_resched:
if (cursor) {
cond_resched();
spin_lock(&key_serial_lock);
goto continue_scanning;
}
/* We've completed the pass. Set the timer if we need to and queue a
* new cycle if necessary. We keep executing cycles until we find one
* where we didn't reap any keys.
*/
kdebug("pass complete");
if (gc_state & KEY_GC_SET_TIMER && new_timer != (time_t)LONG_MAX) {
new_timer += key_gc_delay;
key_schedule_gc(new_timer);
}
if (unlikely(gc_state & KEY_GC_REAPING_DEAD_2) ||
!list_empty(&graveyard)) {
/* Make sure that all pending keyring payload destructions are
* fulfilled and that people aren't now looking at dead or
* dying keys that they don't have a reference upon or a link
* to.
*/
kdebug("gc sync");
synchronize_rcu();
}
if (!list_empty(&graveyard)) {
kdebug("gc keys");
key_gc_unused_keys(&graveyard);
}
if (unlikely(gc_state & (KEY_GC_REAPING_DEAD_1 |
KEY_GC_REAPING_DEAD_2))) {
if (!(gc_state & KEY_GC_FOUND_DEAD_KEY)) {
/* No remaining dead keys: short circuit the remaining
* keytype reap cycles.
*/
kdebug("dead short");
gc_state &= ~(KEY_GC_REAPING_DEAD_1 | KEY_GC_REAPING_DEAD_2);
gc_state |= KEY_GC_REAPING_DEAD_3;
} else {
gc_state |= KEY_GC_REAP_AGAIN;
}
}
if (unlikely(gc_state & KEY_GC_REAPING_DEAD_3)) {
kdebug("dead wake");
smp_mb();
clear_bit(KEY_GC_REAPING_KEYTYPE, &key_gc_flags);
wake_up_bit(&key_gc_flags, KEY_GC_REAPING_KEYTYPE);
}
if (gc_state & KEY_GC_REAP_AGAIN)
schedule_work(&key_gc_work);
kleave(" [end %x]", gc_state);
return;
/* We found an unreferenced key - once we've removed it from the tree,
* we can safely drop the lock.
*/
found_unreferenced_key:
kdebug("unrefd key %d", key->serial);
rb_erase(&key->serial_node, &key_serial_tree);
spin_unlock(&key_serial_lock);
list_add_tail(&key->graveyard_link, &graveyard);
gc_state |= KEY_GC_REAP_AGAIN;
goto maybe_resched;
/* We found a keyring and we need to check the payload for links to
* dead or expired keys. We don't flag another reap immediately as we
* have to wait for the old payload to be destroyed by RCU before we
* can reap the keys to which it refers.
*/
found_keyring:
spin_unlock(&key_serial_lock);
kdebug("scan keyring %d", key->serial);
key_gc_keyring(key, limit);
goto maybe_resched;
/* We found a dead key that is still referenced. Reset its type and
* destroy its payload with its semaphore held.
*/
destroy_dead_key:
spin_unlock(&key_serial_lock);
kdebug("destroy key %d", key->serial);
down_write(&key->sem);
key->type = &key_type_dead;
if (key_gc_dead_keytype->destroy)
key_gc_dead_keytype->destroy(key);
memset(&key->payload, KEY_DESTROY, sizeof(key->payload));
up_write(&key->sem);
goto maybe_resched;
}
/*
* create an authorisation token for /sbin/request-key or whoever to gain
* access to the caller's security data
*/
struct key *request_key_auth_new(struct key *target, const void *callout_info,
size_t callout_len, struct key *dest_keyring)
{
struct request_key_auth *rka, *irka;
const struct cred *cred = current->cred;
struct key *authkey = NULL;
char desc[20];
int ret;
kenter("%d,", target->serial);
/* allocate a auth record */
rka = kmalloc(sizeof(*rka), GFP_KERNEL);
if (!rka) {
kleave(" = -ENOMEM");
return ERR_PTR(-ENOMEM);
}
rka->callout_info = kmalloc(callout_len, GFP_KERNEL);
if (!rka->callout_info) {
kleave(" = -ENOMEM");
kfree(rka);
return ERR_PTR(-ENOMEM);
}
/* see if the calling process is already servicing the key request of
* another process */
if (cred->request_key_auth) {
/* it is - use that instantiation context here too */
down_read(&cred->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, &cred->request_key_auth->flags))
goto auth_key_revoked;
irka = cred->request_key_auth->payload.data;
rka->cred = get_cred(irka->cred);
rka->pid = irka->pid;
up_read(&cred->request_key_auth->sem);
}
else {
/* it isn't - use this process as the context */
rka->cred = get_cred(cred);
rka->pid = current->pid;
}
rka->target_key = key_get(target);
rka->dest_keyring = key_get(dest_keyring);
memcpy(rka->callout_info, callout_info, callout_len);
rka->callout_len = callout_len;
/* allocate the auth key */
sprintf(desc, "%x", target->serial);
authkey = key_alloc(&key_type_request_key_auth, desc,
cred->fsuid, cred->fsgid, cred,
KEY_POS_VIEW | KEY_POS_READ | KEY_POS_SEARCH |
KEY_USR_VIEW, KEY_ALLOC_NOT_IN_QUOTA);
if (IS_ERR(authkey)) {
ret = PTR_ERR(authkey);
goto error_alloc;
}
/* construct the auth key */
ret = key_instantiate_and_link(authkey, rka, 0, NULL, NULL);
if (ret < 0)
goto error_inst;
kleave(" = {%d,%d}", authkey->serial, atomic_read(&authkey->usage));
return authkey;
auth_key_revoked:
up_read(&cred->request_key_auth->sem);
kfree(rka->callout_info);
kfree(rka);
kleave("= -EKEYREVOKED");
return ERR_PTR(-EKEYREVOKED);
error_inst:
key_revoke(authkey);
key_put(authkey);
error_alloc:
key_put(rka->target_key);
key_put(rka->dest_keyring);
kfree(rka->callout_info);
kfree(rka);
kleave("= %d", ret);
return ERR_PTR(ret);
} /* end request_key_auth_new() */
int afs_rxfs_get_root_volume(struct afs_server *server,
char *buf, size_t *buflen)
{
struct rxrpc_connection *conn;
struct rxrpc_call *call;
struct kvec piov[2];
size_t sent;
int ret;
u32 param[1];
DECLARE_WAITQUEUE(myself, current);
kenter("%p,%p,%u",server, buf, *buflen);
/* get hold of the fileserver connection */
ret = afs_server_get_fsconn(server, &conn);
if (ret < 0)
goto out;
/* create a call through that connection */
ret = rxrpc_create_call(conn, NULL, NULL, afs_rxfs_aemap, &call);
if (ret < 0) {
printk("kAFS: Unable to create call: %d\n", ret);
goto out_put_conn;
}
call->app_opcode = FSGETROOTVOLUME;
/* we want to get event notifications from the call */
add_wait_queue(&call->waitq, &myself);
/* marshall the parameters */
param[0] = htonl(FSGETROOTVOLUME);
piov[0].iov_len = sizeof(param);
piov[0].iov_base = param;
/* send the parameters to the server */
ret = rxrpc_call_write_data(call, 1, piov, RXRPC_LAST_PACKET, GFP_NOFS,
0, &sent);
if (ret < 0)
goto abort;
/* wait for the reply to completely arrive */
for (;;) {
set_current_state(TASK_INTERRUPTIBLE);
if (call->app_call_state != RXRPC_CSTATE_CLNT_RCV_REPLY ||
signal_pending(current))
break;
schedule();
}
set_current_state(TASK_RUNNING);
ret = -EINTR;
if (signal_pending(current))
goto abort;
switch (call->app_call_state) {
case RXRPC_CSTATE_ERROR:
ret = call->app_errno;
kdebug("Got Error: %d", ret);
goto out_unwait;
case RXRPC_CSTATE_CLNT_GOT_REPLY:
/* read the reply */
kdebug("Got Reply: qty=%d", call->app_ready_qty);
ret = -EBADMSG;
if (call->app_ready_qty <= 4)
goto abort;
ret = rxrpc_call_read_data(call, NULL, call->app_ready_qty, 0);
if (ret < 0)
goto abort;
#if 0
/* unmarshall the reply */
bp = buffer;
for (loop = 0; loop < 65; loop++)
entry->name[loop] = ntohl(*bp++);
entry->name[64] = 0;
entry->type = ntohl(*bp++);
entry->num_servers = ntohl(*bp++);
for (loop = 0; loop < 8; loop++)
entry->servers[loop].addr.s_addr = *bp++;
for (loop = 0; loop < 8; loop++)
entry->servers[loop].partition = ntohl(*bp++);
for (loop = 0; loop < 8; loop++)
entry->servers[loop].flags = ntohl(*bp++);
for (loop = 0; loop < 3; loop++)
entry->volume_ids[loop] = ntohl(*bp++);
entry->clone_id = ntohl(*bp++);
entry->flags = ntohl(*bp);
#endif
/* success */
ret = 0;
goto out_unwait;
default:
BUG();
}
abort:
set_current_state(TASK_UNINTERRUPTIBLE);
rxrpc_call_abort(call, ret);
schedule();
out_unwait:
set_current_state(TASK_RUNNING);
remove_wait_queue(&call->waitq, &myself);
rxrpc_put_call(call);
out_put_conn:
afs_server_release_fsconn(server, conn);
out:
kleave("");
return ret;
} /* end afs_rxfs_get_root_volume() */
