X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=security%2Fkeys%2Fkey.c;h=700400d801dcc1e5360427bfc07c9c722a256c46;hb=97bf2856c6014879bd04983a3e9dfcdac1e7fe85;hp=0e2584e113082d0af7f2535e5da9c2c1c52ef2f0;hpb=76828883507a47dae78837ab5dec5a5b4513c667;p=linux-2.6.git diff --git a/security/keys/key.c b/security/keys/key.c index 0e2584e11..700400d80 100644 --- a/security/keys/key.c +++ b/security/keys/key.c @@ -1,6 +1,6 @@ /* key.c: basic authentication token and access key management * - * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. + * Copyright (C) 2004-6 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or @@ -11,15 +11,16 @@ #include #include +#include #include #include #include #include +#include #include #include "internal.h" -static kmem_cache_t *key_jar; -static key_serial_t key_serial_next = 3; +static struct kmem_cache *key_jar; struct rb_root key_serial_tree; /* tree of keys indexed by serial */ DEFINE_SPINLOCK(key_serial_lock); @@ -29,8 +30,8 @@ DEFINE_SPINLOCK(key_user_lock); static LIST_HEAD(key_types_list); static DECLARE_RWSEM(key_types_sem); -static void key_cleanup(void *data); -static DECLARE_WORK(key_cleanup_task, key_cleanup, NULL); +static void key_cleanup(struct work_struct *work); +static DECLARE_WORK(key_cleanup_task, key_cleanup); /* we serialise key instantiation and link */ DECLARE_RWSEM(key_construction_sem); @@ -169,23 +170,25 @@ static void __init __key_insert_serial(struct key *key) /*****************************************************************************/ /* * assign a key the next unique serial number - * - we work through all the serial numbers between 2 and 2^31-1 in turn and - * then wrap + * - these are assigned randomly to avoid security issues through covert + * channel problems */ static inline void key_alloc_serial(struct key *key) { struct rb_node *parent, **p; struct key *xkey; - spin_lock(&key_serial_lock); - - /* propose a likely serial number and look for a hole for it in the + /* propose a random serial number and look for a hole for it in the * serial number tree */ - key->serial = key_serial_next; - if (key->serial < 3) - key->serial = 3; - key_serial_next = key->serial + 1; + do { + get_random_bytes(&key->serial, sizeof(key->serial)); + key->serial >>= 1; /* negative numbers are not permitted */ + } while (key->serial < 3); + + spin_lock(&key_serial_lock); + +attempt_insertion: parent = NULL; p = &key_serial_tree.rb_node; @@ -200,40 +203,33 @@ static inline void key_alloc_serial(struct key *key) else goto serial_exists; } - goto insert_here; + + /* we've found a suitable hole - arrange for this key to occupy it */ + rb_link_node(&key->serial_node, parent, p); + rb_insert_color(&key->serial_node, &key_serial_tree); + + spin_unlock(&key_serial_lock); + return; /* we found a key with the proposed serial number - walk the tree from * that point looking for the next unused serial number */ - serial_exists: +serial_exists: for (;;) { - key->serial = key_serial_next; - if (key->serial < 2) - key->serial = 2; - key_serial_next = key->serial + 1; - - if (!parent->rb_parent) - p = &key_serial_tree.rb_node; - else if (parent->rb_parent->rb_left == parent) - p = &parent->rb_parent->rb_left; - else - p = &parent->rb_parent->rb_right; + key->serial++; + if (key->serial < 3) { + key->serial = 3; + goto attempt_insertion; + } parent = rb_next(parent); if (!parent) - break; + goto attempt_insertion; xkey = rb_entry(parent, struct key, serial_node); if (key->serial < xkey->serial) - goto insert_here; + goto attempt_insertion; } - /* we've found a suitable hole - arrange for this key to occupy it */ - insert_here: - rb_link_node(&key->serial_node, parent, p); - rb_insert_color(&key->serial_node, &key_serial_tree); - - spin_unlock(&key_serial_lock); - } /* end key_alloc_serial() */ /*****************************************************************************/ @@ -247,8 +243,8 @@ static inline void key_alloc_serial(struct key *key) * instantiate the key or discard it before returning */ struct key *key_alloc(struct key_type *type, const char *desc, - uid_t uid, gid_t gid, key_perm_t perm, - int not_in_quota) + uid_t uid, gid_t gid, struct task_struct *ctx, + key_perm_t perm, unsigned long flags) { struct key_user *user = NULL; struct key *key; @@ -269,12 +265,14 @@ struct key *key_alloc(struct key_type *type, const char *desc, /* 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; @@ -282,16 +280,14 @@ struct key *key_alloc(struct key_type *type, const char *desc, } /* allocate and initialise the key and its description */ - key = kmem_cache_alloc(key_jar, SLAB_KERNEL); + key = kmem_cache_alloc(key_jar, GFP_KERNEL); if (!key) goto no_memory_2; if (desc) { - key->description = kmalloc(desclen, GFP_KERNEL); + key->description = kmemdup(desc, desclen, GFP_KERNEL); if (!key->description) goto no_memory_3; - - memcpy(key->description, desc, desclen); } atomic_set(&key->usage, 1); @@ -308,7 +304,7 @@ struct key *key_alloc(struct key_type *type, const char *desc, 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 +314,7 @@ struct key *key_alloc(struct key_type *type, const char *desc, #endif /* let the security module know about the key */ - ret = security_key_alloc(key); + ret = security_key_alloc(key, ctx, flags); if (ret < 0) goto security_error; @@ -332,7 +328,7 @@ error: 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 +341,7 @@ security_error: 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; @@ -549,7 +545,7 @@ EXPORT_SYMBOL(key_negate_and_link); * do cleaning up in process context so that we don't have to disable * interrupts all over the place */ -static void key_cleanup(void *data) +static void key_cleanup(struct work_struct *work) { struct rb_node *_n; struct key *key; @@ -761,7 +757,7 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref, 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; @@ -799,12 +795,16 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref, goto error_3; } - /* search for an existing key of the same type and description in the - * destination keyring + /* if it's possible to update this type of key, search for an existing + * key of the same type and description in the destination keyring and + * update that instead if possible */ - key_ref = __keyring_search_one(keyring_ref, ktype, description, 0); - if (!IS_ERR(key_ref)) - goto found_matching_key; + if (ktype->update) { + key_ref = __keyring_search_one(keyring_ref, ktype, description, + 0); + if (!IS_ERR(key_ref)) + goto found_matching_key; + } /* decide on the permissions we want */ perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR; @@ -818,7 +818,7 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref, /* allocate a new key */ key = key_alloc(ktype, description, current->fsuid, current->fsgid, - perm, not_in_quota); + current, perm, flags); if (IS_ERR(key)) { key_ref = ERR_PTR(PTR_ERR(key)); goto error_3; @@ -903,6 +903,10 @@ void key_revoke(struct key *key) * it */ down_write(&key->sem); set_bit(KEY_FLAG_REVOKED, &key->flags); + + if (key->type->revoke) + key->type->revoke(key); + up_write(&key->sem); } /* end key_revoke() */ @@ -978,7 +982,7 @@ void unregister_key_type(struct key_type *ktype) if (key->type == ktype) { if (ktype->destroy) ktype->destroy(key); - memset(&key->payload, 0xbd, sizeof(key->payload)); + memset(&key->payload, KEY_DESTROY, sizeof(key->payload)); } }