diff options
Diffstat (limited to 'security/keys')
-rw-r--r-- | security/keys/Makefile | 1 | ||||
-rw-r--r-- | security/keys/compat.c | 3 | ||||
-rw-r--r-- | security/keys/internal.h | 30 | ||||
-rw-r--r-- | security/keys/key.c | 86 | ||||
-rw-r--r-- | security/keys/keyctl.c | 126 | ||||
-rw-r--r-- | security/keys/keyring.c | 54 | ||||
-rw-r--r-- | security/keys/proc.c | 17 | ||||
-rw-r--r-- | security/keys/process_keys.c | 142 | ||||
-rw-r--r-- | security/keys/request_key.c | 50 | ||||
-rw-r--r-- | security/keys/request_key_auth.c | 13 | ||||
-rw-r--r-- | security/keys/sysctl.c | 50 |
11 files changed, 382 insertions, 190 deletions
diff --git a/security/keys/Makefile b/security/keys/Makefile index 5145adfb6a05..747a464943af 100644 --- a/security/keys/Makefile +++ b/security/keys/Makefile @@ -14,3 +14,4 @@ obj-y := \ obj-$(CONFIG_KEYS_COMPAT) += compat.o obj-$(CONFIG_PROC_FS) += proc.o +obj-$(CONFIG_SYSCTL) += sysctl.o diff --git a/security/keys/compat.c b/security/keys/compat.c index e10ec995f275..c766c68a63bc 100644 --- a/security/keys/compat.c +++ b/security/keys/compat.c @@ -79,6 +79,9 @@ asmlinkage long compat_sys_keyctl(u32 option, case KEYCTL_ASSUME_AUTHORITY: return keyctl_assume_authority(arg2); + case KEYCTL_GET_SECURITY: + return keyctl_get_security(arg2, compat_ptr(arg3), arg4); + default: return -EOPNOTSUPP; } diff --git a/security/keys/internal.h b/security/keys/internal.h index 7d894ef70370..8c05587f5018 100644 --- a/security/keys/internal.h +++ b/security/keys/internal.h @@ -57,10 +57,6 @@ struct key_user { int qnbytes; /* number of bytes allocated to this user */ }; -#define KEYQUOTA_MAX_KEYS 100 -#define KEYQUOTA_MAX_BYTES 10000 -#define KEYQUOTA_LINK_BYTES 4 /* a link in a keyring is worth 4 bytes */ - extern struct rb_root key_user_tree; extern spinlock_t key_user_lock; extern struct key_user root_key_user; @@ -68,6 +64,16 @@ extern struct key_user root_key_user; extern struct key_user *key_user_lookup(uid_t uid); extern void key_user_put(struct key_user *user); +/* + * key quota limits + * - root has its own separate limits to everyone else + */ +extern unsigned key_quota_root_maxkeys; +extern unsigned key_quota_root_maxbytes; +extern unsigned key_quota_maxkeys; +extern unsigned key_quota_maxbytes; + +#define KEYQUOTA_LINK_BYTES 4 /* a link in a keyring is worth 4 bytes */ extern struct rb_root key_serial_tree; @@ -77,8 +83,6 @@ 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, @@ -102,14 +106,15 @@ 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); extern struct key *request_key_and_link(struct key_type *type, const char *description, - const char *callout_info, + const void *callout_info, + size_t callout_len, void *aux, struct key *dest_keyring, unsigned long flags); @@ -120,13 +125,15 @@ extern struct key *request_key_and_link(struct key_type *type, struct request_key_auth { struct key *target_key; struct task_struct *context; - char *callout_info; + void *callout_info; + size_t callout_len; pid_t pid; }; extern struct key_type key_type_request_key_auth; extern struct key *request_key_auth_new(struct key *target, - const char *callout_info); + const void *callout_info, + size_t callout_len); extern struct key *key_get_instantiation_authkey(key_serial_t target_id); @@ -152,7 +159,8 @@ extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t); extern long keyctl_set_reqkey_keyring(int); extern long keyctl_set_timeout(key_serial_t, unsigned); extern long keyctl_assume_authority(key_serial_t); - +extern long keyctl_get_security(key_serial_t keyid, char __user *buffer, + size_t buflen); /* * debugging key validation diff --git a/security/keys/key.c b/security/keys/key.c index 654d23baf352..14948cf83ef6 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 @@ -27,6 +27,11 @@ DEFINE_SPINLOCK(key_serial_lock); struct rb_root key_user_tree; /* tree of quota records indexed by UID */ DEFINE_SPINLOCK(key_user_lock); +unsigned int key_quota_root_maxkeys = 200; /* root's key count quota */ +unsigned int key_quota_root_maxbytes = 20000; /* root's key space quota */ +unsigned int key_quota_maxkeys = 200; /* general key count quota */ +unsigned int key_quota_maxbytes = 20000; /* general key space quota */ + static LIST_HEAD(key_types_list); static DECLARE_RWSEM(key_types_sem); @@ -139,36 +144,6 @@ 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 @@ -266,11 +241,16 @@ 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 (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { + unsigned maxkeys = (uid == 0) ? + key_quota_root_maxkeys : key_quota_maxkeys; + unsigned maxbytes = (uid == 0) ? + key_quota_root_maxbytes : key_quota_maxbytes; + spin_lock(&user->lock); if (!(flags & KEY_ALLOC_QUOTA_OVERRUN)) { - if (user->qnkeys + 1 >= KEYQUOTA_MAX_KEYS || - user->qnbytes + quotalen >= KEYQUOTA_MAX_BYTES - ) + if (user->qnkeys + 1 >= maxkeys || + user->qnbytes + quotalen >= maxbytes || + user->qnbytes + quotalen < user->qnbytes) goto no_quota; } @@ -375,11 +355,14 @@ int key_payload_reserve(struct key *key, size_t datalen) /* contemplate the quota adjustment */ if (delta != 0 && test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { + unsigned maxbytes = (key->user->uid == 0) ? + key_quota_root_maxbytes : key_quota_maxbytes; + spin_lock(&key->user->lock); if (delta > 0 && - key->user->qnbytes + delta > KEYQUOTA_MAX_BYTES - ) { + (key->user->qnbytes + delta >= maxbytes || + key->user->qnbytes + delta < key->user->qnbytes)) { ret = -EDQUOT; } else { @@ -757,11 +740,11 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref, const char *description, const void *payload, size_t plen, + key_perm_t perm, unsigned long flags) { struct key_type *ktype; struct key *keyring, *key = NULL; - key_perm_t perm; key_ref_t key_ref; int ret; @@ -806,15 +789,17 @@ 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 | KEY_POS_SETATTR; - perm |= KEY_USR_VIEW | KEY_USR_SEARCH | KEY_USR_LINK | KEY_USR_SETATTR; + /* if the client doesn't provide, decide on the permissions we want */ + if (perm == KEY_PERM_UNDEF) { + 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; + if (ktype->read) + perm |= KEY_POS_READ | KEY_USR_READ; - if (ktype == &key_type_keyring || ktype->update) - perm |= KEY_USR_WRITE; + if (ktype == &key_type_keyring || ktype->update) + perm |= KEY_USR_WRITE; + } /* allocate a new key */ key = key_alloc(ktype, description, current->fsuid, current->fsgid, @@ -1018,17 +1003,4 @@ 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/keyctl.c b/security/keys/keyctl.c index d9ca15c109cc..acc9c89e40a8 100644 --- a/security/keys/keyctl.c +++ b/security/keys/keyctl.c @@ -19,6 +19,8 @@ #include <linux/capability.h> #include <linux/string.h> #include <linux/err.h> +#include <linux/vmalloc.h> +#include <linux/security.h> #include <asm/uaccess.h> #include "internal.h" @@ -62,9 +64,10 @@ asmlinkage long sys_add_key(const char __user *_type, char type[32], *description; void *payload; long ret; + bool vm; ret = -EINVAL; - if (plen > 32767) + if (plen > 1024 * 1024 - 1) goto error; /* draw all the data into kernel space */ @@ -81,11 +84,18 @@ asmlinkage long sys_add_key(const char __user *_type, /* pull the payload in if one was supplied */ payload = NULL; + vm = false; if (_payload) { ret = -ENOMEM; payload = kmalloc(plen, GFP_KERNEL); - if (!payload) - goto error2; + if (!payload) { + if (plen <= PAGE_SIZE) + goto error2; + vm = true; + payload = vmalloc(plen); + if (!payload) + goto error2; + } ret = -EFAULT; if (copy_from_user(payload, _payload, plen) != 0) @@ -102,7 +112,8 @@ asmlinkage long sys_add_key(const char __user *_type, /* create or update the requested key and add it to the target * keyring */ key_ref = key_create_or_update(keyring_ref, type, description, - payload, plen, KEY_ALLOC_IN_QUOTA); + payload, plen, KEY_PERM_UNDEF, + KEY_ALLOC_IN_QUOTA); if (!IS_ERR(key_ref)) { ret = key_ref_to_ptr(key_ref)->serial; key_ref_put(key_ref); @@ -113,7 +124,10 @@ asmlinkage long sys_add_key(const char __user *_type, key_ref_put(keyring_ref); error3: - kfree(payload); + if (!vm) + kfree(payload); + else + vfree(payload); error2: kfree(description); error: @@ -140,6 +154,7 @@ asmlinkage long sys_request_key(const char __user *_type, struct key_type *ktype; struct key *key; key_ref_t dest_ref; + size_t callout_len; char type[32], *description, *callout_info; long ret; @@ -157,12 +172,14 @@ asmlinkage long sys_request_key(const char __user *_type, /* pull the callout info into kernel space */ callout_info = NULL; + callout_len = 0; if (_callout_info) { callout_info = strndup_user(_callout_info, PAGE_SIZE); if (IS_ERR(callout_info)) { ret = PTR_ERR(callout_info); goto error2; } + callout_len = strlen(callout_info); } /* get the destination keyring if specified */ @@ -183,8 +200,8 @@ asmlinkage long sys_request_key(const char __user *_type, } /* do the search */ - key = request_key_and_link(ktype, description, callout_info, NULL, - key_ref_to_ptr(dest_ref), + key = request_key_and_link(ktype, description, callout_info, + callout_len, NULL, key_ref_to_ptr(dest_ref), KEY_ALLOC_IN_QUOTA); if (IS_ERR(key)) { ret = PTR_ERR(key); @@ -714,10 +731,16 @@ long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid) /* transfer the quota burden to the new user */ if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { + unsigned maxkeys = (uid == 0) ? + key_quota_root_maxkeys : key_quota_maxkeys; + unsigned maxbytes = (uid == 0) ? + key_quota_root_maxbytes : key_quota_maxbytes; + spin_lock(&newowner->lock); - if (newowner->qnkeys + 1 >= KEYQUOTA_MAX_KEYS || - newowner->qnbytes + key->quotalen >= - KEYQUOTA_MAX_BYTES) + if (newowner->qnkeys + 1 >= maxkeys || + newowner->qnbytes + key->quotalen >= maxbytes || + newowner->qnbytes + key->quotalen < + newowner->qnbytes) goto quota_overrun; newowner->qnkeys++; @@ -821,9 +844,10 @@ long keyctl_instantiate_key(key_serial_t id, key_ref_t keyring_ref; void *payload; long ret; + bool vm = false; ret = -EINVAL; - if (plen > 32767) + if (plen > 1024 * 1024 - 1) goto error; /* the appropriate instantiation authorisation key must have been @@ -843,8 +867,14 @@ long keyctl_instantiate_key(key_serial_t id, if (_payload) { ret = -ENOMEM; payload = kmalloc(plen, GFP_KERNEL); - if (!payload) - goto error; + if (!payload) { + if (plen <= PAGE_SIZE) + goto error; + vm = true; + payload = vmalloc(plen); + if (!payload) + goto error; + } ret = -EFAULT; if (copy_from_user(payload, _payload, plen) != 0) @@ -877,7 +907,10 @@ long keyctl_instantiate_key(key_serial_t id, } error2: - kfree(payload); + if (!vm) + kfree(payload); + else + vfree(payload); error: return ret; @@ -1055,6 +1088,66 @@ error: } /* end keyctl_assume_authority() */ +/* + * get the security label of a key + * - the key must grant us view permission + * - if there's a buffer, we place up to buflen bytes of data into it + * - unless there's an error, we return the amount of information available, + * irrespective of how much we may have copied (including the terminal NUL) + * - implements keyctl(KEYCTL_GET_SECURITY) + */ +long keyctl_get_security(key_serial_t keyid, + char __user *buffer, + size_t buflen) +{ + struct key *key, *instkey; + key_ref_t key_ref; + char *context; + long ret; + + key_ref = lookup_user_key(NULL, keyid, 0, 1, KEY_VIEW); + if (IS_ERR(key_ref)) { + if (PTR_ERR(key_ref) != -EACCES) + return PTR_ERR(key_ref); + + /* viewing a key under construction is also permitted if we + * have the authorisation token handy */ + instkey = key_get_instantiation_authkey(keyid); + if (IS_ERR(instkey)) + return PTR_ERR(key_ref); + key_put(instkey); + + key_ref = lookup_user_key(NULL, keyid, 0, 1, 0); + if (IS_ERR(key_ref)) + return PTR_ERR(key_ref); + } + + key = key_ref_to_ptr(key_ref); + ret = security_key_getsecurity(key, &context); + if (ret == 0) { + /* if no information was returned, give userspace an empty + * string */ + ret = 1; + if (buffer && buflen > 0 && + copy_to_user(buffer, "", 1) != 0) + ret = -EFAULT; + } else if (ret > 0) { + /* return as much data as there's room for */ + if (buffer && buflen > 0) { + if (buflen > ret) + buflen = ret; + + if (copy_to_user(buffer, context, buflen) != 0) + ret = -EFAULT; + } + + kfree(context); + } + + key_ref_put(key_ref); + return ret; +} + /*****************************************************************************/ /* * the key control system call @@ -1135,6 +1228,11 @@ asmlinkage long sys_keyctl(int option, unsigned long arg2, unsigned long arg3, case KEYCTL_ASSUME_AUTHORITY: return keyctl_assume_authority((key_serial_t) arg2); + case KEYCTL_GET_SECURITY: + return keyctl_get_security((key_serial_t) arg2, + (char *) arg3, + (size_t) arg4); + default: return -EOPNOTSUPP; } diff --git a/security/keys/keyring.c b/security/keys/keyring.c index 88292e3dee96..a9ab8affc092 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; @@ -292,7 +292,7 @@ key_ref_t keyring_search_aux(key_ref_t keyring_ref, struct keyring_list *keylist; struct timespec now; - unsigned long possessed; + unsigned long possessed, kflags; struct key *keyring, *key; key_ref_t key_ref; long err; @@ -319,6 +319,32 @@ key_ref_t keyring_search_aux(key_ref_t keyring_ref, err = -EAGAIN; sp = 0; + /* firstly we should check to see if this top-level keyring is what we + * are looking for */ + key_ref = ERR_PTR(-EAGAIN); + kflags = keyring->flags; + if (keyring->type == type && match(keyring, description)) { + key = keyring; + + /* check it isn't negative and hasn't expired or been + * revoked */ + if (kflags & (1 << KEY_FLAG_REVOKED)) + goto error_2; + if (key->expiry && now.tv_sec >= key->expiry) + goto error_2; + key_ref = ERR_PTR(-ENOKEY); + if (kflags & (1 << KEY_FLAG_NEGATIVE)) + goto error_2; + goto found; + } + + /* otherwise, the top keyring must not be revoked, expired, or + * negatively instantiated if we are to search it */ + key_ref = ERR_PTR(-EAGAIN); + if (kflags & ((1 << KEY_FLAG_REVOKED) | (1 << KEY_FLAG_NEGATIVE)) || + (keyring->expiry && now.tv_sec >= keyring->expiry)) + goto error_2; + /* start processing a new keyring */ descend: if (test_bit(KEY_FLAG_REVOKED, &keyring->flags)) @@ -331,13 +357,14 @@ descend: /* iterate through the keys in this keyring first */ for (kix = 0; kix < keylist->nkeys; kix++) { key = keylist->keys[kix]; + kflags = key->flags; /* ignore keys not of this type */ if (key->type != type) continue; /* skip revoked keys and expired keys */ - if (test_bit(KEY_FLAG_REVOKED, &key->flags)) + if (kflags & (1 << KEY_FLAG_REVOKED)) continue; if (key->expiry && now.tv_sec >= key->expiry) @@ -352,8 +379,8 @@ descend: context, KEY_SEARCH) < 0) continue; - /* we set a different error code if we find a negative key */ - if (test_bit(KEY_FLAG_NEGATIVE, &key->flags)) { + /* we set a different error code if we pass a negative key */ + if (kflags & (1 << KEY_FLAG_NEGATIVE)) { err = -ENOKEY; continue; } @@ -489,10 +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; @@ -518,15 +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/proc.c b/security/keys/proc.c index 694126003ed3..f619170da760 100644 --- a/security/keys/proc.c +++ b/security/keys/proc.c @@ -70,19 +70,15 @@ static int __init key_proc_init(void) struct proc_dir_entry *p; #ifdef CONFIG_KEYS_DEBUG_PROC_KEYS - p = create_proc_entry("keys", 0, NULL); + p = proc_create("keys", 0, NULL, &proc_keys_fops); if (!p) panic("Cannot create /proc/keys\n"); - - p->proc_fops = &proc_keys_fops; #endif - p = create_proc_entry("key-users", 0, NULL); + p = proc_create("key-users", 0, NULL, &proc_key_users_fops); if (!p) panic("Cannot create /proc/key-users\n"); - p->proc_fops = &proc_key_users_fops; - return 0; } /* end key_proc_init() */ @@ -246,6 +242,10 @@ static int proc_key_users_show(struct seq_file *m, void *v) { struct rb_node *_p = v; struct key_user *user = rb_entry(_p, struct key_user, node); + unsigned maxkeys = (user->uid == 0) ? + key_quota_root_maxkeys : key_quota_maxkeys; + unsigned maxbytes = (user->uid == 0) ? + key_quota_root_maxbytes : key_quota_maxbytes; seq_printf(m, "%5u: %5d %d/%d %d/%d %d/%d\n", user->uid, @@ -253,10 +253,9 @@ static int proc_key_users_show(struct seq_file *m, void *v) atomic_read(&user->nkeys), atomic_read(&user->nikeys), user->qnkeys, - KEYQUOTA_MAX_KEYS, + maxkeys, user->qnbytes, - KEYQUOTA_MAX_BYTES - ); + maxbytes); return 0; diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c index c886a2bb792a..5be6d018759a 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/keys/request_key.c b/security/keys/request_key.c index 5ecc5057fb54..ba32ca6469bd 100644 --- a/security/keys/request_key.c +++ b/security/keys/request_key.c @@ -16,6 +16,7 @@ #include <linux/kmod.h> #include <linux/err.h> #include <linux/keyctl.h> +#include <linux/slab.h> #include "internal.h" /* @@ -161,21 +162,22 @@ error_alloc: * call out to userspace for key construction * - we ignore program failure and go on key status instead */ -static int construct_key(struct key *key, const char *callout_info, void *aux) +static int construct_key(struct key *key, const void *callout_info, + size_t callout_len, void *aux) { struct key_construction *cons; request_key_actor_t actor; struct key *authkey; int ret; - kenter("%d,%s,%p", key->serial, callout_info, aux); + 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); + authkey = request_key_auth_new(key, callout_info, callout_len); if (IS_ERR(authkey)) { kfree(cons); ret = PTR_ERR(authkey); @@ -331,6 +333,7 @@ alloc_failed: 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) @@ -348,7 +351,7 @@ static struct key *construct_key_and_link(struct key_type *type, key_user_put(user); if (ret == 0) { - ret = construct_key(key, callout_info, aux); + ret = construct_key(key, callout_info, callout_len, aux); if (ret < 0) goto construction_failed; } @@ -370,7 +373,8 @@ construction_failed: */ struct key *request_key_and_link(struct key_type *type, const char *description, - const char *callout_info, + const void *callout_info, + size_t callout_len, void *aux, struct key *dest_keyring, unsigned long flags) @@ -378,8 +382,8 @@ struct key *request_key_and_link(struct key_type *type, struct key *key; key_ref_t key_ref; - kenter("%s,%s,%s,%p,%p,%lx", - type->name, description, callout_info, aux, + 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 */ @@ -398,7 +402,8 @@ struct key *request_key_and_link(struct key_type *type, goto error; key = construct_key_and_link(type, description, callout_info, - aux, dest_keyring, flags); + callout_len, aux, dest_keyring, + flags); } error: @@ -434,10 +439,13 @@ struct key *request_key(struct key_type *type, const char *callout_info) { struct key *key; + size_t callout_len = 0; int ret; - key = request_key_and_link(type, description, callout_info, NULL, - NULL, KEY_ALLOC_IN_QUOTA); + if (callout_info) + callout_len = strlen(callout_info); + key = request_key_and_link(type, description, callout_info, callout_len, + NULL, NULL, KEY_ALLOC_IN_QUOTA); if (!IS_ERR(key)) { ret = wait_for_key_construction(key, false); if (ret < 0) { @@ -458,14 +466,15 @@ EXPORT_SYMBOL(request_key); */ struct key *request_key_with_auxdata(struct key_type *type, const char *description, - const char *callout_info, + const void *callout_info, + size_t callout_len, void *aux) { struct key *key; int ret; - key = request_key_and_link(type, description, callout_info, aux, - NULL, KEY_ALLOC_IN_QUOTA); + key = request_key_and_link(type, description, callout_info, callout_len, + aux, NULL, KEY_ALLOC_IN_QUOTA); if (!IS_ERR(key)) { ret = wait_for_key_construction(key, false); if (ret < 0) { @@ -485,10 +494,12 @@ EXPORT_SYMBOL(request_key_with_auxdata); */ struct key *request_key_async(struct key_type *type, const char *description, - const char *callout_info) + const void *callout_info, + size_t callout_len) { - return request_key_and_link(type, description, callout_info, NULL, - NULL, KEY_ALLOC_IN_QUOTA); + return request_key_and_link(type, description, callout_info, + callout_len, NULL, NULL, + KEY_ALLOC_IN_QUOTA); } EXPORT_SYMBOL(request_key_async); @@ -500,10 +511,11 @@ EXPORT_SYMBOL(request_key_async); */ struct key *request_key_async_with_auxdata(struct key_type *type, const char *description, - const char *callout_info, + const void *callout_info, + size_t callout_len, void *aux) { - return request_key_and_link(type, description, callout_info, aux, - NULL, KEY_ALLOC_IN_QUOTA); + return request_key_and_link(type, description, callout_info, + callout_len, aux, NULL, KEY_ALLOC_IN_QUOTA); } EXPORT_SYMBOL(request_key_async_with_auxdata); diff --git a/security/keys/request_key_auth.c b/security/keys/request_key_auth.c index e42b5252486f..bd237b0a6331 100644 --- a/security/keys/request_key_auth.c +++ b/security/keys/request_key_auth.c @@ -15,6 +15,7 @@ #include <linux/sched.h> #include <linux/err.h> #include <linux/seq_file.h> +#include <linux/slab.h> #include <asm/uaccess.h> #include "internal.h" @@ -61,7 +62,7 @@ static void request_key_auth_describe(const struct key *key, seq_puts(m, "key:"); seq_puts(m, key->description); - seq_printf(m, " pid:%d ci:%zu", rka->pid, strlen(rka->callout_info)); + seq_printf(m, " pid:%d ci:%zu", rka->pid, rka->callout_len); } /* end request_key_auth_describe() */ @@ -77,7 +78,7 @@ static long request_key_auth_read(const struct key *key, size_t datalen; long ret; - datalen = strlen(rka->callout_info); + datalen = rka->callout_len; ret = datalen; /* we can return the data as is */ @@ -137,7 +138,8 @@ static void request_key_auth_destroy(struct key *key) * 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 char *callout_info) +struct key *request_key_auth_new(struct key *target, const void *callout_info, + size_t callout_len) { struct request_key_auth *rka, *irka; struct key *authkey = NULL; @@ -152,7 +154,7 @@ struct key *request_key_auth_new(struct key *target, const char *callout_info) kleave(" = -ENOMEM"); return ERR_PTR(-ENOMEM); } - rka->callout_info = kmalloc(strlen(callout_info) + 1, GFP_KERNEL); + rka->callout_info = kmalloc(callout_len, GFP_KERNEL); if (!rka->callout_info) { kleave(" = -ENOMEM"); kfree(rka); @@ -186,7 +188,8 @@ struct key *request_key_auth_new(struct key *target, const char *callout_info) } rka->target_key = key_get(target); - strcpy(rka->callout_info, callout_info); + memcpy(rka->callout_info, callout_info, callout_len); + rka->callout_len = callout_len; /* allocate the auth key */ sprintf(desc, "%x", target->serial); diff --git a/security/keys/sysctl.c b/security/keys/sysctl.c new file mode 100644 index 000000000000..b611d493c2d8 --- /dev/null +++ b/security/keys/sysctl.c @@ -0,0 +1,50 @@ +/* Key management controls + * + * Copyright (C) 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 + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ + +#include <linux/key.h> +#include <linux/sysctl.h> +#include "internal.h" + +ctl_table key_sysctls[] = { + { + .ctl_name = CTL_UNNUMBERED, + .procname = "maxkeys", + .data = &key_quota_maxkeys, + .maxlen = sizeof(unsigned), + .mode = 0644, + .proc_handler = &proc_dointvec, + }, + { + .ctl_name = CTL_UNNUMBERED, + .procname = "maxbytes", + .data = &key_quota_maxbytes, + .maxlen = sizeof(unsigned), + .mode = 0644, + .proc_handler = &proc_dointvec, + }, + { + .ctl_name = CTL_UNNUMBERED, + .procname = "root_maxkeys", + .data = &key_quota_root_maxkeys, + .maxlen = sizeof(unsigned), + .mode = 0644, + .proc_handler = &proc_dointvec, + }, + { + .ctl_name = CTL_UNNUMBERED, + .procname = "root_maxbytes", + .data = &key_quota_root_maxbytes, + .maxlen = sizeof(unsigned), + .mode = 0644, + .proc_handler = &proc_dointvec, + }, + { .ctl_name = 0 } +}; |