diff options
| -rw-r--r-- | include/linux/key.h | 8 | ||||
| -rw-r--r-- | kernel/user.c | 15 | ||||
| -rw-r--r-- | security/keys/internal.h | 4 | ||||
| -rw-r--r-- | security/keys/key.c | 45 | ||||
| -rw-r--r-- | security/keys/keyring.c | 19 | ||||
| -rw-r--r-- | security/keys/process_keys.c | 142 | ||||
| -rw-r--r-- | security/selinux/hooks.c | 8 |
7 files changed, 96 insertions, 145 deletions
diff --git a/include/linux/key.h b/include/linux/key.h index 8b0bd33..2effd03 100644 --- a/include/linux/key.h +++ b/include/linux/key.h @@ -268,9 +268,6 @@ extern struct key *key_lookup(key_serial_t id); /* * the userspace interface */ -extern struct key root_user_keyring, root_session_keyring; -extern int alloc_uid_keyring(struct user_struct *user, - struct task_struct *ctx); extern void switch_uid_keyring(struct user_struct *new_user); extern int copy_keys(unsigned long clone_flags, struct task_struct *tsk); extern int copy_thread_group_keys(struct task_struct *tsk); @@ -299,7 +296,6 @@ extern void key_init(void); #define make_key_ref(k, p) ({ NULL; }) #define key_ref_to_ptr(k) ({ NULL; }) #define is_key_possessed(k) 0 -#define alloc_uid_keyring(u,c) 0 #define switch_uid_keyring(u) do { } while(0) #define __install_session_keyring(t, k) ({ NULL; }) #define copy_keys(f,t) 0 @@ -312,10 +308,6 @@ extern void key_init(void); #define key_fsgid_changed(t) do { } while(0) #define key_init() do { } while(0) -/* Initial keyrings */ -extern struct key root_user_keyring; -extern struct key root_session_keyring; - #endif /* CONFIG_KEYS */ #endif /* __KERNEL__ */ #endif /* _LINUX_KEY_H */ diff --git a/kernel/user.c b/kernel/user.c index debce60..aefbbfa 100644 --- a/kernel/user.c +++ b/kernel/user.c @@ -53,10 +53,6 @@ struct user_struct root_user = { .files = ATOMIC_INIT(0), .sigpending = ATOMIC_INIT(0), .locked_shm = 0, -#ifdef CONFIG_KEYS - .uid_keyring = &root_user_keyring, - .session_keyring = &root_session_keyring, -#endif #ifdef CONFIG_USER_SCHED .tg = &init_task_group, #endif @@ -420,12 +416,12 @@ struct user_struct * alloc_uid(struct user_namespace *ns, uid_t uid) new->mq_bytes = 0; #endif new->locked_shm = 0; - - if (alloc_uid_keyring(new, current) < 0) - goto out_free_user; +#ifdef CONFIG_KEYS + new->uid_keyring = new->session_keyring = NULL; +#endif if (sched_create_user(new) < 0) - goto out_put_keys; + goto out_free_user; if (uids_user_create(new)) goto out_destoy_sched; @@ -459,9 +455,6 @@ struct user_struct * alloc_uid(struct user_namespace *ns, uid_t uid) out_destoy_sched: sched_destroy_user(new); -out_put_keys: - key_put(new->uid_keyring); - key_put(new->session_keyring); out_free_user: kmem_cache_free(uid_cachep, new); out_unlock: diff --git a/security/keys/internal.h b/security/keys/internal.h index 6361d37..2ab3885 100644 --- a/security/keys/internal.h +++ b/security/keys/internal.h @@ -77,8 +77,6 @@ extern struct mutex key_construction_mutex; extern wait_queue_head_t request_key_conswq; -extern void keyring_publish_name(struct key *keyring); - extern int __key_link(struct key *keyring, struct key *key); extern key_ref_t __keyring_search_one(key_ref_t keyring_ref, @@ -102,7 +100,7 @@ extern key_ref_t search_process_keyrings(struct key_type *type, key_match_func_t match, struct task_struct *tsk); -extern struct key *find_keyring_by_name(const char *name, key_serial_t bound); +extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check); extern int install_thread_keyring(struct task_struct *tsk); extern int install_process_keyring(struct task_struct *tsk); diff --git a/security/keys/key.c b/security/keys/key.c index d98c619..46f125a 100644 --- a/security/keys/key.c +++ b/security/keys/key.c @@ -1,6 +1,6 @@ /* Basic authentication token and access key management * - * Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved. + * Copyright (C) 2004-2008 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or @@ -139,36 +139,6 @@ void key_user_put(struct key_user *user) /*****************************************************************************/ /* - * insert a key with a fixed serial number - */ -static void __init __key_insert_serial(struct key *key) -{ - struct rb_node *parent, **p; - struct key *xkey; - - parent = NULL; - p = &key_serial_tree.rb_node; - - while (*p) { - parent = *p; - xkey = rb_entry(parent, struct key, serial_node); - - if (key->serial < xkey->serial) - p = &(*p)->rb_left; - else if (key->serial > xkey->serial) - p = &(*p)->rb_right; - else - BUG(); - } - - /* 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); - -} /* end __key_insert_serial() */ - -/*****************************************************************************/ -/* * assign a key the next unique serial number * - these are assigned randomly to avoid security issues through covert * channel problems @@ -1020,17 +990,4 @@ void __init key_init(void) rb_insert_color(&root_key_user.node, &key_user_tree); - /* record root's user standard keyrings */ - key_check(&root_user_keyring); - key_check(&root_session_keyring); - - __key_insert_serial(&root_user_keyring); - __key_insert_serial(&root_session_keyring); - - keyring_publish_name(&root_user_keyring); - keyring_publish_name(&root_session_keyring); - - /* link the two root keyrings together */ - key_link(&root_session_keyring, &root_user_keyring); - } /* end key_init() */ diff --git a/security/keys/keyring.c b/security/keys/keyring.c index 70f0c31..a9ab8af 100644 --- a/security/keys/keyring.c +++ b/security/keys/keyring.c @@ -1,6 +1,6 @@ -/* keyring.c: keyring handling +/* Keyring handling * - * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved. + * Copyright (C) 2004-2005, 2008 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or @@ -79,7 +79,7 @@ static DECLARE_RWSEM(keyring_serialise_link_sem); * publish the name of a keyring so that it can be found by name (if it has * one) */ -void keyring_publish_name(struct key *keyring) +static void keyring_publish_name(struct key *keyring) { int bucket; @@ -516,10 +516,9 @@ key_ref_t __keyring_search_one(key_ref_t keyring_ref, /* * find a keyring with the specified name * - all named keyrings are searched - * - only find keyrings with search permission for the process - * - only find keyrings with a serial number greater than the one specified + * - normally only finds keyrings with search permission for the current process */ -struct key *find_keyring_by_name(const char *name, key_serial_t bound) +struct key *find_keyring_by_name(const char *name, bool skip_perm_check) { struct key *keyring; int bucket; @@ -545,15 +544,11 @@ struct key *find_keyring_by_name(const char *name, key_serial_t bound) if (strcmp(keyring->description, name) != 0) continue; - if (key_permission(make_key_ref(keyring, 0), + if (!skip_perm_check && + key_permission(make_key_ref(keyring, 0), KEY_SEARCH) < 0) continue; - /* found a potential candidate, but we still need to - * check the serial number */ - if (keyring->serial <= bound) - continue; - /* we've got a match */ atomic_inc(&keyring->usage); read_unlock(&keyring_name_lock); diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c index c886a2b..5be6d01 100644 --- a/security/keys/process_keys.c +++ b/security/keys/process_keys.c @@ -1,6 +1,6 @@ -/* process_keys.c: management of a process's keyrings +/* Management of a process's keyrings * - * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved. + * Copyright (C) 2004-2005, 2008 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or @@ -23,6 +23,9 @@ /* session keyring create vs join semaphore */ static DEFINE_MUTEX(key_session_mutex); +/* user keyring creation semaphore */ +static DEFINE_MUTEX(key_user_keyring_mutex); + /* the root user's tracking struct */ struct key_user root_key_user = { .usage = ATOMIC_INIT(3), @@ -33,78 +36,84 @@ struct key_user root_key_user = { .uid = 0, }; -/* the root user's UID keyring */ -struct key root_user_keyring = { - .usage = ATOMIC_INIT(1), - .serial = 2, - .type = &key_type_keyring, - .user = &root_key_user, - .sem = __RWSEM_INITIALIZER(root_user_keyring.sem), - .perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL, - .flags = 1 << KEY_FLAG_INSTANTIATED, - .description = "_uid.0", -#ifdef KEY_DEBUGGING - .magic = KEY_DEBUG_MAGIC, -#endif -}; - -/* the root user's default session keyring */ -struct key root_session_keyring = { - .usage = ATOMIC_INIT(1), - .serial = 1, - .type = &key_type_keyring, - .user = &root_key_user, - .sem = __RWSEM_INITIALIZER(root_session_keyring.sem), - .perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL, - .flags = 1 << KEY_FLAG_INSTANTIATED, - .description = "_uid_ses.0", -#ifdef KEY_DEBUGGING - .magic = KEY_DEBUG_MAGIC, -#endif -}; - /*****************************************************************************/ /* - * allocate the keyrings to be associated with a UID + * install user and user session keyrings for a particular UID */ -int alloc_uid_keyring(struct user_struct *user, - struct task_struct *ctx) +static int install_user_keyrings(struct task_struct *tsk) { + struct user_struct *user = tsk->user; struct key *uid_keyring, *session_keyring; char buf[20]; int ret; - /* concoct a default session keyring */ - sprintf(buf, "_uid_ses.%u", user->uid); + kenter("%p{%u}", user, user->uid); - 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; + if (user->uid_keyring) { + kleave(" = 0 [exist]"); + return 0; } - /* and a UID specific keyring, pointed to by the default session - * keyring */ - sprintf(buf, "_uid.%u", user->uid); + mutex_lock(&key_user_keyring_mutex); + ret = 0; - 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); - goto error; + 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, + tsk, 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, + tsk, 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; } - /* install the keyrings */ - user->uid_keyring = uid_keyring; - user->session_keyring = session_keyring; - ret = 0; + 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; - -} /* end alloc_uid_keyring() */ +} /*****************************************************************************/ /* @@ -481,7 +490,7 @@ key_ref_t search_process_keyrings(struct key_type *type, } } /* or search the user-session keyring */ - else { + else if (context->user->session_keyring) { key_ref = keyring_search_aux( make_key_ref(context->user->session_keyring, 1), context, type, description, match); @@ -614,6 +623,9 @@ key_ref_t lookup_user_key(struct task_struct *context, key_serial_t id, if (!context->signal->session_keyring) { /* always install a session keyring upon access if one * doesn't exist yet */ + ret = install_user_keyrings(context); + if (ret < 0) + goto error; ret = install_session_keyring( context, context->user->session_keyring); if (ret < 0) @@ -628,12 +640,24 @@ key_ref_t lookup_user_key(struct task_struct *context, key_serial_t id, break; case KEY_SPEC_USER_KEYRING: + if (!context->user->uid_keyring) { + ret = install_user_keyrings(context); + if (ret < 0) + goto error; + } + key = context->user->uid_keyring; atomic_inc(&key->usage); key_ref = make_key_ref(key, 1); break; case KEY_SPEC_USER_SESSION_KEYRING: + if (!context->user->session_keyring) { + ret = install_user_keyrings(context); + if (ret < 0) + goto error; + } + key = context->user->session_keyring; atomic_inc(&key->usage); key_ref = make_key_ref(key, 1); @@ -744,7 +768,7 @@ long join_session_keyring(const char *name) mutex_lock(&key_session_mutex); /* look for an existing keyring of this name */ - keyring = find_keyring_by_name(name, 0); + keyring = find_keyring_by_name(name, false); if (PTR_ERR(keyring) == -ENOKEY) { /* not found - try and create a new one */ keyring = keyring_alloc(name, tsk->uid, tsk->gid, tsk, diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 838d1e5..4e4de98 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -5551,14 +5551,6 @@ static __init int selinux_init(void) else printk(KERN_DEBUG "SELinux: Starting in permissive mode\n"); -#ifdef CONFIG_KEYS - /* Add security information to initial keyrings */ - selinux_key_alloc(&root_user_keyring, current, - KEY_ALLOC_NOT_IN_QUOTA); - selinux_key_alloc(&root_session_keyring, current, - KEY_ALLOC_NOT_IN_QUOTA); -#endif - return 0; } |
