diff options
| -rw-r--r-- | Documentation/keys.txt | 22 | ||||
| -rw-r--r-- | include/linux/key-ui.h | 3 | ||||
| -rw-r--r-- | include/linux/key.h | 13 | ||||
| -rw-r--r-- | include/linux/security.h | 73 | ||||
| -rw-r--r-- | security/dummy.c | 23 | ||||
| -rw-r--r-- | security/keys/key.c | 56 | ||||
| -rw-r--r-- | security/keys/keyctl.c | 13 | ||||
| -rw-r--r-- | security/keys/keyring.c | 21 | ||||
| -rw-r--r-- | security/keys/permission.c | 7 | ||||
| -rw-r--r-- | security/keys/process_keys.c | 9 |
10 files changed, 191 insertions, 49 deletions
diff --git a/Documentation/keys.txt b/Documentation/keys.txt index 4afe03a..3115488 100644 --- a/Documentation/keys.txt +++ b/Documentation/keys.txt @@ -196,7 +196,7 @@ KEY ACCESS PERMISSIONS Keys have an owner user ID, a group access ID, and a permissions mask. The mask has up to eight bits each for possessor, user, group and other access. Only -five of each set of eight bits are defined. These permissions granted are: +six of each set of eight bits are defined. These permissions granted are: (*) View @@ -224,6 +224,10 @@ five of each set of eight bits are defined. These permissions granted are: keyring to a key, a process must have Write permission on the keyring and Link permission on the key. + (*) Set Attribute + + This permits a key's UID, GID and permissions mask to be changed. + For changing the ownership, group ID or permissions mask, being the owner of the key or having the sysadmin capability is sufficient. @@ -242,15 +246,15 @@ about the status of the key service: this way: SERIAL FLAGS USAGE EXPY PERM UID GID TYPE DESCRIPTION: SUMMARY - 00000001 I----- 39 perm 1f1f0000 0 0 keyring _uid_ses.0: 1/4 - 00000002 I----- 2 perm 1f1f0000 0 0 keyring _uid.0: empty - 00000007 I----- 1 perm 1f1f0000 0 0 keyring _pid.1: empty - 0000018d I----- 1 perm 1f1f0000 0 0 keyring _pid.412: empty - 000004d2 I--Q-- 1 perm 1f1f0000 32 -1 keyring _uid.32: 1/4 - 000004d3 I--Q-- 3 perm 1f1f0000 32 -1 keyring _uid_ses.32: empty + 00000001 I----- 39 perm 1f3f0000 0 0 keyring _uid_ses.0: 1/4 + 00000002 I----- 2 perm 1f3f0000 0 0 keyring _uid.0: empty + 00000007 I----- 1 perm 1f3f0000 0 0 keyring _pid.1: empty + 0000018d I----- 1 perm 1f3f0000 0 0 keyring _pid.412: empty + 000004d2 I--Q-- 1 perm 1f3f0000 32 -1 keyring _uid.32: 1/4 + 000004d3 I--Q-- 3 perm 1f3f0000 32 -1 keyring _uid_ses.32: empty 00000892 I--QU- 1 perm 1f000000 0 0 user metal:copper: 0 - 00000893 I--Q-N 1 35s 1f1f0000 0 0 user metal:silver: 0 - 00000894 I--Q-- 1 10h 001f0000 0 0 user metal:gold: 0 + 00000893 I--Q-N 1 35s 1f3f0000 0 0 user metal:silver: 0 + 00000894 I--Q-- 1 10h 003f0000 0 0 user metal:gold: 0 The flags are: diff --git a/include/linux/key-ui.h b/include/linux/key-ui.h index 7a2e332..e8b8a7a 100644 --- a/include/linux/key-ui.h +++ b/include/linux/key-ui.h @@ -24,7 +24,8 @@ extern spinlock_t key_serial_lock; #define KEY_WRITE 0x04 /* require permission to update / modify */ #define KEY_SEARCH 0x08 /* require permission to search (keyring) or find (key) */ #define KEY_LINK 0x10 /* require permission to link */ -#define KEY_ALL 0x1f /* all the above permissions */ +#define KEY_SETATTR 0x20 /* require permission to change attributes */ +#define KEY_ALL 0x3f /* all the above permissions */ /* * the keyring payload contains a list of the keys to which the keyring is diff --git a/include/linux/key.h b/include/linux/key.h index f1efa01..53513a3 100644 --- a/include/linux/key.h +++ b/include/linux/key.h @@ -40,28 +40,32 @@ struct key; #define KEY_POS_WRITE 0x04000000 /* possessor can update key payload / add link to keyring */ #define KEY_POS_SEARCH 0x08000000 /* possessor can find a key in search / search a keyring */ #define KEY_POS_LINK 0x10000000 /* possessor can create a link to a key/keyring */ -#define KEY_POS_ALL 0x1f000000 +#define KEY_POS_SETATTR 0x20000000 /* possessor can set key attributes */ +#define KEY_POS_ALL 0x3f000000 #define KEY_USR_VIEW 0x00010000 /* user permissions... */ #define KEY_USR_READ 0x00020000 #define KEY_USR_WRITE 0x00040000 #define KEY_USR_SEARCH 0x00080000 #define KEY_USR_LINK 0x00100000 -#define KEY_USR_ALL 0x001f0000 +#define KEY_USR_SETATTR 0x00200000 +#define KEY_USR_ALL 0x003f0000 #define KEY_GRP_VIEW 0x00000100 /* group permissions... */ #define KEY_GRP_READ 0x00000200 #define KEY_GRP_WRITE 0x00000400 #define KEY_GRP_SEARCH 0x00000800 #define KEY_GRP_LINK 0x00001000 -#define KEY_GRP_ALL 0x00001f00 +#define KEY_GRP_SETATTR 0x00002000 +#define KEY_GRP_ALL 0x00003f00 #define KEY_OTH_VIEW 0x00000001 /* third party permissions... */ #define KEY_OTH_READ 0x00000002 #define KEY_OTH_WRITE 0x00000004 #define KEY_OTH_SEARCH 0x00000008 #define KEY_OTH_LINK 0x00000010 -#define KEY_OTH_ALL 0x0000001f +#define KEY_OTH_SETATTR 0x00000020 +#define KEY_OTH_ALL 0x0000003f struct seq_file; struct user_struct; @@ -119,6 +123,7 @@ struct key { struct key_type *type; /* type of key */ struct rw_semaphore sem; /* change vs change sem */ struct key_user *user; /* owner of this key */ + void *security; /* security data for this key */ time_t expiry; /* time at which key expires (or 0) */ uid_t uid; gid_t gid; diff --git a/include/linux/security.h b/include/linux/security.h index 607ee20..f7e0ae0 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -30,6 +30,7 @@ #include <linux/shm.h> #include <linux/msg.h> #include <linux/sched.h> +#include <linux/key.h> struct ctl_table; @@ -788,6 +789,27 @@ struct swap_info_struct; * @sk_free_security: * Deallocate security structure. * + * Security hooks affecting all Key Management operations + * + * @key_alloc: + * Permit allocation of a key and assign security data. Note that key does + * not have a serial number assigned at this point. + * @key points to the key. + * Return 0 if permission is granted, -ve error otherwise. + * @key_free: + * Notification of destruction; free security data. + * @key points to the key. + * No return value. + * @key_permission: + * See whether a specific operational right is granted to a process on a + * key. + * @key_ref refers to the key (key pointer + possession attribute bit). + * @context points to the process to provide the context against which to + * evaluate the security data on the key. + * @perm describes the combination of permissions required of this key. + * Return 1 if permission granted, 0 if permission denied and -ve it the + * normal permissions model should be effected. + * * Security hooks affecting all System V IPC operations. * * @ipc_permission: @@ -1216,6 +1238,17 @@ struct security_operations { int (*sk_alloc_security) (struct sock *sk, int family, gfp_t priority); void (*sk_free_security) (struct sock *sk); #endif /* CONFIG_SECURITY_NETWORK */ + + /* key management security hooks */ +#ifdef CONFIG_KEYS + int (*key_alloc)(struct key *key); + void (*key_free)(struct key *key); + int (*key_permission)(key_ref_t key_ref, + struct task_struct *context, + key_perm_t perm); + +#endif /* CONFIG_KEYS */ + }; /* global variables */ @@ -2764,5 +2797,45 @@ static inline void security_sk_free(struct sock *sk) } #endif /* CONFIG_SECURITY_NETWORK */ +#ifdef CONFIG_KEYS +#ifdef CONFIG_SECURITY +static inline int security_key_alloc(struct key *key) +{ + return security_ops->key_alloc(key); +} + +static inline void security_key_free(struct key *key) +{ + security_ops->key_free(key); +} + +static inline int security_key_permission(key_ref_t key_ref, + struct task_struct *context, + key_perm_t perm) +{ + return security_ops->key_permission(key_ref, context, perm); +} + +#else + +static inline int security_key_alloc(struct key *key) +{ + return 0; +} + +static inline void security_key_free(struct key *key) +{ +} + +static inline int security_key_permission(key_ref_t key_ref, + struct task_struct *context, + key_perm_t perm) +{ + return 0; +} + +#endif +#endif /* CONFIG_KEYS */ + #endif /* ! __LINUX_SECURITY_H */ diff --git a/security/dummy.c b/security/dummy.c index 2a0337a..3ca5f2b 100644 --- a/security/dummy.c +++ b/security/dummy.c @@ -803,6 +803,23 @@ static int dummy_setprocattr(struct task_struct *p, char *name, void *value, siz return -EINVAL; } +#ifdef CONFIG_KEYS +static inline int dummy_key_alloc(struct key *key) +{ + return 0; +} + +static inline void dummy_key_free(struct key *key) +{ +} + +static inline int dummy_key_permission(key_ref_t key_ref, + struct task_struct *context, + key_perm_t perm) +{ + return 0; +} +#endif /* CONFIG_KEYS */ struct security_operations dummy_security_ops; @@ -954,5 +971,11 @@ void security_fixup_ops (struct security_operations *ops) set_to_dummy_if_null(ops, sk_alloc_security); set_to_dummy_if_null(ops, sk_free_security); #endif /* CONFIG_SECURITY_NETWORK */ +#ifdef CONFIG_KEYS + set_to_dummy_if_null(ops, key_alloc); + set_to_dummy_if_null(ops, key_free); + set_to_dummy_if_null(ops, key_permission); +#endif /* CONFIG_KEYS */ + } diff --git a/security/keys/key.c b/security/keys/key.c index 2182be9..ccde17a 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) 2004-5 Red Hat, Inc. All Rights Reserved. + * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or @@ -13,6 +13,7 @@ #include <linux/init.h> #include <linux/sched.h> #include <linux/slab.h> +#include <linux/security.h> #include <linux/workqueue.h> #include <linux/err.h> #include "internal.h" @@ -253,6 +254,7 @@ struct key *key_alloc(struct key_type *type, const char *desc, struct key_user *user = NULL; struct key *key; size_t desclen, quotalen; + int ret; key = ERR_PTR(-EINVAL); if (!desc || !*desc) @@ -305,6 +307,7 @@ struct key *key_alloc(struct key_type *type, const char *desc, key->flags = 0; key->expiry = 0; key->payload.data = NULL; + key->security = NULL; if (!not_in_quota) key->flags |= 1 << KEY_FLAG_IN_QUOTA; @@ -315,16 +318,34 @@ struct key *key_alloc(struct key_type *type, const char *desc, key->magic = KEY_DEBUG_MAGIC; #endif + /* let the security module know about the key */ + ret = security_key_alloc(key); + if (ret < 0) + goto security_error; + /* publish the key by giving it a serial number */ atomic_inc(&user->nkeys); key_alloc_serial(key); - error: +error: return key; - no_memory_3: +security_error: + kfree(key->description); + kmem_cache_free(key_jar, key); + if (!not_in_quota) { + spin_lock(&user->lock); + user->qnkeys--; + user->qnbytes -= quotalen; + spin_unlock(&user->lock); + } + key_user_put(user); + key = ERR_PTR(ret); + goto error; + +no_memory_3: kmem_cache_free(key_jar, key); - no_memory_2: +no_memory_2: if (!not_in_quota) { spin_lock(&user->lock); user->qnkeys--; @@ -332,11 +353,11 @@ struct key *key_alloc(struct key_type *type, const char *desc, spin_unlock(&user->lock); } key_user_put(user); - no_memory_1: +no_memory_1: key = ERR_PTR(-ENOMEM); goto error; - no_quota: +no_quota: spin_unlock(&user->lock); key_user_put(user); key = ERR_PTR(-EDQUOT); @@ -556,6 +577,8 @@ static void key_cleanup(void *data) key_check(key); + security_key_free(key); + /* deal with the user's key tracking and quota */ if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { spin_lock(&key->user->lock); @@ -700,8 +723,8 @@ static inline key_ref_t __key_update(key_ref_t key_ref, int ret; /* need write permission on the key to update it */ - ret = -EACCES; - if (!key_permission(key_ref, KEY_WRITE)) + ret = key_permission(key_ref, KEY_WRITE); + if (ret < 0) goto error; ret = -EEXIST; @@ -711,7 +734,6 @@ static inline key_ref_t __key_update(key_ref_t key_ref, down_write(&key->sem); ret = key->type->update(key, payload, plen); - if (ret == 0) /* updating a negative key instantiates it */ clear_bit(KEY_FLAG_NEGATIVE, &key->flags); @@ -768,9 +790,11 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref, /* if we're going to allocate a new key, we're going to have * to modify the keyring */ - key_ref = ERR_PTR(-EACCES); - if (!key_permission(keyring_ref, KEY_WRITE)) + ret = key_permission(keyring_ref, KEY_WRITE); + if (ret < 0) { + key_ref = ERR_PTR(ret); goto error_3; + } /* search for an existing key of the same type and description in the * destination keyring @@ -780,8 +804,8 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref, goto found_matching_key; /* decide on the permissions we want */ - perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK; - perm |= KEY_USR_VIEW | KEY_USR_SEARCH | KEY_USR_LINK; + perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR; + perm |= KEY_USR_VIEW | KEY_USR_SEARCH | KEY_USR_LINK | KEY_USR_SETATTR; if (ktype->read) perm |= KEY_POS_READ | KEY_USR_READ; @@ -840,16 +864,16 @@ int key_update(key_ref_t key_ref, const void *payload, size_t plen) key_check(key); /* the key must be writable */ - ret = -EACCES; - if (!key_permission(key_ref, KEY_WRITE)) + ret = key_permission(key_ref, KEY_WRITE); + if (ret < 0) goto error; /* attempt to update it if supported */ ret = -EOPNOTSUPP; if (key->type->update) { down_write(&key->sem); - ret = key->type->update(key, payload, plen); + ret = key->type->update(key, payload, plen); if (ret == 0) /* updating a negative key instantiates it */ clear_bit(KEY_FLAG_NEGATIVE, &key->flags); diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c index 4c670ee..b7a468f 100644 --- a/security/keys/keyctl.c +++ b/security/keys/keyctl.c @@ -624,8 +624,8 @@ long keyctl_keyring_search(key_serial_t ringid, /* link the resulting key to the destination keyring if we can */ if (dest_ref) { - ret = -EACCES; - if (!key_permission(key_ref, KEY_LINK)) + ret = key_permission(key_ref, KEY_LINK); + if (ret < 0) goto error6; ret = key_link(key_ref_to_ptr(dest_ref), key_ref_to_ptr(key_ref)); @@ -676,8 +676,11 @@ long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen) key = key_ref_to_ptr(key_ref); /* see if we can read it directly */ - if (key_permission(key_ref, KEY_READ)) + ret = key_permission(key_ref, KEY_READ); + if (ret == 0) goto can_read_key; + if (ret != -EACCES) + goto error; /* we can't; see if it's searchable from this process's keyrings * - we automatically take account of the fact that it may be @@ -726,7 +729,7 @@ long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid) if (uid == (uid_t) -1 && gid == (gid_t) -1) goto error; - key_ref = lookup_user_key(NULL, id, 1, 1, 0); + key_ref = lookup_user_key(NULL, id, 1, 1, KEY_SETATTR); if (IS_ERR(key_ref)) { ret = PTR_ERR(key_ref); goto error; @@ -786,7 +789,7 @@ long keyctl_setperm_key(key_serial_t id, key_perm_t perm) if (perm & ~(KEY_POS_ALL | KEY_USR_ALL | KEY_GRP_ALL | KEY_OTH_ALL)) goto error; - key_ref = lookup_user_key(NULL, id, 1, 1, 0); + key_ref = lookup_user_key(NULL, id, 1, 1, KEY_SETATTR); if (IS_ERR(key_ref)) { ret = PTR_ERR(key_ref); goto error; diff --git a/security/keys/keyring.c b/security/keys/keyring.c index 0639396..e1cc4dd 100644 --- a/security/keys/keyring.c +++ b/security/keys/keyring.c @@ -13,6 +13,7 @@ #include <linux/init.h> #include <linux/sched.h> #include <linux/slab.h> +#include <linux/security.h> #include <linux/seq_file.h> #include <linux/err.h> #include <asm/uaccess.h> @@ -309,7 +310,9 @@ struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid, int ret; keyring = key_alloc(&key_type_keyring, description, - uid, gid, KEY_POS_ALL | KEY_USR_ALL, not_in_quota); + uid, gid, + (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL, + not_in_quota); if (!IS_ERR(keyring)) { ret = key_instantiate_and_link(keyring, NULL, 0, dest, NULL); @@ -359,9 +362,11 @@ key_ref_t keyring_search_aux(key_ref_t keyring_ref, key_check(keyring); /* top keyring must have search permission to begin the search */ - key_ref = ERR_PTR(-EACCES); - if (!key_task_permission(keyring_ref, context, KEY_SEARCH)) + err = key_task_permission(keyring_ref, context, KEY_SEARCH); + if (err < 0) { + key_ref = ERR_PTR(err); goto error; + } key_ref = ERR_PTR(-ENOTDIR); if (keyring->type != &key_type_keyring) @@ -402,8 +407,8 @@ descend: continue; /* key must have search permissions */ - if (!key_task_permission(make_key_ref(key, possessed), - context, KEY_SEARCH)) + if (key_task_permission(make_key_ref(key, possessed), + context, KEY_SEARCH) < 0) continue; /* we set a different error code if we find a negative key */ @@ -430,7 +435,7 @@ ascend: continue; if (!key_task_permission(make_key_ref(key, possessed), - context, KEY_SEARCH)) + context, KEY_SEARCH) < 0) continue; /* stack the current position */ @@ -521,7 +526,7 @@ key_ref_t __keyring_search_one(key_ref_t keyring_ref, (!key->type->match || key->type->match(key, description)) && key_permission(make_key_ref(key, possessed), - perm) && + perm) < 0 && !test_bit(KEY_FLAG_REVOKED, &key->flags) ) goto found; @@ -617,7 +622,7 @@ struct key *find_keyring_by_name(const char *name, key_serial_t bound) continue; if (!key_permission(make_key_ref(keyring, 0), - KEY_SEARCH)) + KEY_SEARCH) < 0) continue; /* found a potential candidate, but we still need to diff --git a/security/keys/permission.c b/security/keys/permission.c index 03db073..e7f579c 100644 --- a/security/keys/permission.c +++ b/security/keys/permission.c @@ -10,6 +10,7 @@ */ #include <linux/module.h> +#include <linux/security.h> #include "internal.h" /*****************************************************************************/ @@ -63,7 +64,11 @@ use_these_perms: kperm = kperm & perm & KEY_ALL; - return kperm == perm; + if (kperm != perm) + return -EACCES; + + /* let LSM be the final arbiter */ + return security_key_permission(key_ref, context, perm); } /* end key_task_permission() */ diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c index d42d215..566b1cc 100644 --- a/security/keys/process_keys.c +++ b/security/keys/process_keys.c @@ -39,7 +39,7 @@ struct key root_user_keyring = { .type = &key_type_keyring, .user = &root_key_user, .sem = __RWSEM_INITIALIZER(root_user_keyring.sem), - .perm = KEY_POS_ALL | KEY_USR_ALL, + .perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL, .flags = 1 << KEY_FLAG_INSTANTIATED, .description = "_uid.0", #ifdef KEY_DEBUGGING @@ -54,7 +54,7 @@ struct key root_session_keyring = { .type = &key_type_keyring, .user = &root_key_user, .sem = __RWSEM_INITIALIZER(root_session_keyring.sem), - .perm = KEY_POS_ALL | KEY_USR_ALL, + .perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL, .flags = 1 << KEY_FLAG_INSTANTIATED, .description = "_uid_ses.0", #ifdef KEY_DEBUGGING @@ -666,9 +666,8 @@ key_ref_t lookup_user_key(struct task_struct *context, key_serial_t id, goto invalid_key; /* check the permissions */ - ret = -EACCES; - - if (!key_task_permission(key_ref, context, perm)) + ret = key_task_permission(key_ref, context, perm); + if (ret < 0) goto invalid_key; error: |
