diff options
author | David Woodhouse <dwmw2@shinybook.infradead.org> | 2005-07-02 13:39:09 +0100 |
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committer | David Woodhouse <dwmw2@shinybook.infradead.org> | 2005-07-02 13:39:09 +0100 |
commit | d2f6409584e2c62ffad81690562330ff3bf4a458 (patch) | |
tree | 3bdfb97d0b51be2f7f414f2107e97603c1206abb /security | |
parent | e1b09eba2686eca94a3a188042b518df6044a3c1 (diff) | |
parent | 4a89a04f1ee21a7c1f4413f1ad7dcfac50ff9b63 (diff) | |
download | op-kernel-dev-d2f6409584e2c62ffad81690562330ff3bf4a458.zip op-kernel-dev-d2f6409584e2c62ffad81690562330ff3bf4a458.tar.gz |
Merge with master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
Diffstat (limited to 'security')
-rw-r--r-- | security/commoncap.c | 2 | ||||
-rw-r--r-- | security/dummy.c | 2 | ||||
-rw-r--r-- | security/keys/Makefile | 5 | ||||
-rw-r--r-- | security/keys/compat.c | 7 | ||||
-rw-r--r-- | security/keys/internal.h | 45 | ||||
-rw-r--r-- | security/keys/key.c | 118 | ||||
-rw-r--r-- | security/keys/keyctl.c | 199 | ||||
-rw-r--r-- | security/keys/keyring.c | 312 | ||||
-rw-r--r-- | security/keys/proc.c | 21 | ||||
-rw-r--r-- | security/keys/process_keys.c | 213 | ||||
-rw-r--r-- | security/keys/request_key.c | 221 | ||||
-rw-r--r-- | security/keys/request_key_auth.c | 180 | ||||
-rw-r--r-- | security/keys/user_defined.c | 87 | ||||
-rw-r--r-- | security/seclvl.c | 4 | ||||
-rw-r--r-- | security/selinux/hooks.c | 28 | ||||
-rw-r--r-- | security/selinux/include/av_perm_to_string.h | 2 | ||||
-rw-r--r-- | security/selinux/include/av_permissions.h | 2 | ||||
-rw-r--r-- | security/selinux/selinuxfs.c | 9 | ||||
-rw-r--r-- | security/selinux/ss/conditional.c | 9 | ||||
-rw-r--r-- | security/selinux/ss/policydb.c | 15 | ||||
-rw-r--r-- | security/selinux/ss/services.c | 6 |
21 files changed, 1036 insertions, 451 deletions
diff --git a/security/commoncap.c b/security/commoncap.c index 849b8c3..04c12f5 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -149,7 +149,7 @@ void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe) if (bprm->e_uid != current->uid || bprm->e_gid != current->gid || !cap_issubset (new_permitted, current->cap_permitted)) { - current->mm->dumpable = 0; + current->mm->dumpable = suid_dumpable; if (unsafe & ~LSM_UNSAFE_PTRACE_CAP) { if (!capable(CAP_SETUID)) { diff --git a/security/dummy.c b/security/dummy.c index b32eff1..6ff8875 100644 --- a/security/dummy.c +++ b/security/dummy.c @@ -130,7 +130,7 @@ static void dummy_bprm_free_security (struct linux_binprm *bprm) static void dummy_bprm_apply_creds (struct linux_binprm *bprm, int unsafe) { if (bprm->e_uid != current->uid || bprm->e_gid != current->gid) { - current->mm->dumpable = 0; + current->mm->dumpable = suid_dumpable; if ((unsafe & ~LSM_UNSAFE_PTRACE_CAP) && !capable(CAP_SETUID)) { bprm->e_uid = current->uid; diff --git a/security/keys/Makefile b/security/keys/Makefile index ddb495d6..c392d75 100644 --- a/security/keys/Makefile +++ b/security/keys/Makefile @@ -7,8 +7,9 @@ obj-y := \ keyring.o \ keyctl.o \ process_keys.o \ - user_defined.o \ - request_key.o + request_key.o \ + request_key_auth.o \ + user_defined.o obj-$(CONFIG_KEYS_COMPAT) += compat.o obj-$(CONFIG_PROC_FS) += proc.o diff --git a/security/keys/compat.c b/security/keys/compat.c index aff8b22..3303673 100644 --- a/security/keys/compat.c +++ b/security/keys/compat.c @@ -1,6 +1,6 @@ /* compat.c: 32-bit compatibility syscall for 64-bit systems * - * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. + * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or @@ -24,7 +24,7 @@ * - if you can, you should call sys_keyctl directly */ asmlinkage long compat_sys_keyctl(u32 option, - u32 arg2, u32 arg3, u32 arg4, u32 arg5) + u32 arg2, u32 arg3, u32 arg4, u32 arg5) { switch (option) { case KEYCTL_GET_KEYRING_ID: @@ -71,6 +71,9 @@ asmlinkage long compat_sys_keyctl(u32 option, case KEYCTL_NEGATE: return keyctl_negate_key(arg2, arg3, arg4); + case KEYCTL_SET_REQKEY_KEYRING: + return keyctl_set_reqkey_keyring(arg2); + default: return -EOPNOTSUPP; } diff --git a/security/keys/internal.h b/security/keys/internal.h index 67b2b93..46c8602 100644 --- a/security/keys/internal.h +++ b/security/keys/internal.h @@ -1,6 +1,6 @@ /* internal.h: authentication token and access key management internal defs * - * Copyright (C) 2003 Red Hat, Inc. All Rights Reserved. + * Copyright (C) 2003-5 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or @@ -15,6 +15,16 @@ #include <linux/key.h> #include <linux/key-ui.h> +#if 0 +#define kenter(FMT, a...) printk("==> %s("FMT")\n",__FUNCTION__ , ## a) +#define kleave(FMT, a...) printk("<== %s()"FMT"\n",__FUNCTION__ , ## a) +#define kdebug(FMT, a...) printk(FMT"\n" , ## a) +#else +#define kenter(FMT, a...) do {} while(0) +#define kleave(FMT, a...) do {} while(0) +#define kdebug(FMT, a...) do {} while(0) +#endif + extern struct key_type key_type_dead; extern struct key_type key_type_user; @@ -66,20 +76,46 @@ extern struct key *__keyring_search_one(struct key *keyring, const char *description, key_perm_t perm); +extern struct key *keyring_search_instkey(struct key *keyring, + key_serial_t target_id); + typedef int (*key_match_func_t)(const struct key *, const void *); extern struct key *keyring_search_aux(struct key *keyring, + struct task_struct *tsk, struct key_type *type, const void *description, key_match_func_t match); -extern struct key *search_process_keyrings_aux(struct key_type *type, - const void *description, - key_match_func_t match); +extern struct key *search_process_keyrings(struct key_type *type, + const void *description, + key_match_func_t match, + struct task_struct *tsk); extern struct key *find_keyring_by_name(const char *name, key_serial_t bound); 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, + struct key *dest_keyring); + +/* + * request_key authorisation + */ +struct request_key_auth { + struct key *target_key; + struct task_struct *context; + pid_t pid; +}; + +extern struct key_type key_type_request_key_auth; +extern struct key *request_key_auth_new(struct key *target, + struct key **_rkakey); + +extern struct key *key_get_instantiation_authkey(key_serial_t target_id); /* * keyctl functions @@ -100,6 +136,7 @@ extern long keyctl_setperm_key(key_serial_t, key_perm_t); extern long keyctl_instantiate_key(key_serial_t, const void __user *, size_t, key_serial_t); extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t); +extern long keyctl_set_reqkey_keyring(int); /* diff --git a/security/keys/key.c b/security/keys/key.c index 59402c8..fb89f98 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) 2004-5 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or @@ -294,7 +294,6 @@ struct key *key_alloc(struct key_type *type, const char *desc, } atomic_set(&key->usage, 1); - rwlock_init(&key->lock); init_rwsem(&key->sem); key->type = type; key->user = user; @@ -308,7 +307,7 @@ struct key *key_alloc(struct key_type *type, const char *desc, key->payload.data = NULL; if (!not_in_quota) - key->flags |= KEY_FLAG_IN_QUOTA; + key->flags |= 1 << KEY_FLAG_IN_QUOTA; memset(&key->type_data, 0, sizeof(key->type_data)); @@ -359,7 +358,7 @@ int key_payload_reserve(struct key *key, size_t datalen) key_check(key); /* contemplate the quota adjustment */ - if (delta != 0 && key->flags & KEY_FLAG_IN_QUOTA) { + if (delta != 0 && test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { spin_lock(&key->user->lock); if (delta > 0 && @@ -392,7 +391,8 @@ EXPORT_SYMBOL(key_payload_reserve); static int __key_instantiate_and_link(struct key *key, const void *data, size_t datalen, - struct key *keyring) + struct key *keyring, + struct key *instkey) { int ret, awaken; @@ -405,27 +405,25 @@ static int __key_instantiate_and_link(struct key *key, down_write(&key_construction_sem); /* can't instantiate twice */ - if (!(key->flags & KEY_FLAG_INSTANTIATED)) { + if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) { /* instantiate the key */ ret = key->type->instantiate(key, data, datalen); if (ret == 0) { /* mark the key as being instantiated */ - write_lock(&key->lock); - atomic_inc(&key->user->nikeys); - key->flags |= KEY_FLAG_INSTANTIATED; + set_bit(KEY_FLAG_INSTANTIATED, &key->flags); - if (key->flags & KEY_FLAG_USER_CONSTRUCT) { - key->flags &= ~KEY_FLAG_USER_CONSTRUCT; + if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) awaken = 1; - } - - write_unlock(&key->lock); /* and link it into the destination keyring */ if (keyring) ret = __key_link(keyring, key); + + /* disable the authorisation key */ + if (instkey) + key_revoke(instkey); } } @@ -446,19 +444,21 @@ static int __key_instantiate_and_link(struct key *key, int key_instantiate_and_link(struct key *key, const void *data, size_t datalen, - struct key *keyring) + struct key *keyring, + struct key *instkey) { int ret; if (keyring) down_write(&keyring->sem); - ret = __key_instantiate_and_link(key, data, datalen, keyring); + ret = __key_instantiate_and_link(key, data, datalen, keyring, instkey); if (keyring) up_write(&keyring->sem); return ret; + } /* end key_instantiate_and_link() */ EXPORT_SYMBOL(key_instantiate_and_link); @@ -469,7 +469,8 @@ EXPORT_SYMBOL(key_instantiate_and_link); */ int key_negate_and_link(struct key *key, unsigned timeout, - struct key *keyring) + struct key *keyring, + struct key *instkey) { struct timespec now; int ret, awaken; @@ -486,26 +487,26 @@ int key_negate_and_link(struct key *key, down_write(&key_construction_sem); /* can't instantiate twice */ - if (!(key->flags & KEY_FLAG_INSTANTIATED)) { + if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) { /* mark the key as being negatively instantiated */ - write_lock(&key->lock); - atomic_inc(&key->user->nikeys); - key->flags |= KEY_FLAG_INSTANTIATED | KEY_FLAG_NEGATIVE; + set_bit(KEY_FLAG_NEGATIVE, &key->flags); + set_bit(KEY_FLAG_INSTANTIATED, &key->flags); now = current_kernel_time(); key->expiry = now.tv_sec + timeout; - if (key->flags & KEY_FLAG_USER_CONSTRUCT) { - key->flags &= ~KEY_FLAG_USER_CONSTRUCT; + if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) awaken = 1; - } - write_unlock(&key->lock); ret = 0; /* and link it into the destination keyring */ if (keyring) ret = __key_link(keyring, key); + + /* disable the authorisation key */ + if (instkey) + key_revoke(instkey); } up_write(&key_construction_sem); @@ -553,8 +554,10 @@ static void key_cleanup(void *data) rb_erase(&key->serial_node, &key_serial_tree); spin_unlock(&key_serial_lock); + key_check(key); + /* deal with the user's key tracking and quota */ - if (key->flags & KEY_FLAG_IN_QUOTA) { + if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { spin_lock(&key->user->lock); key->user->qnkeys--; key->user->qnbytes -= key->quotalen; @@ -562,7 +565,7 @@ static void key_cleanup(void *data) } atomic_dec(&key->user->nkeys); - if (key->flags & KEY_FLAG_INSTANTIATED) + if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) atomic_dec(&key->user->nikeys); key_user_put(key->user); @@ -631,9 +634,9 @@ struct key *key_lookup(key_serial_t id) goto error; found: - /* pretent doesn't exist if it's dead */ + /* pretend it doesn't exist if it's dead */ if (atomic_read(&key->usage) == 0 || - (key->flags & KEY_FLAG_DEAD) || + test_bit(KEY_FLAG_DEAD, &key->flags) || key->type == &key_type_dead) goto not_found; @@ -708,12 +711,9 @@ static inline struct key *__key_update(struct key *key, const void *payload, ret = key->type->update(key, payload, plen); - if (ret == 0) { + if (ret == 0) /* updating a negative key instantiates it */ - write_lock(&key->lock); - key->flags &= ~KEY_FLAG_NEGATIVE; - write_unlock(&key->lock); - } + clear_bit(KEY_FLAG_NEGATIVE, &key->flags); up_write(&key->sem); @@ -793,7 +793,7 @@ struct key *key_create_or_update(struct key *keyring, } /* instantiate it and link it into the target keyring */ - ret = __key_instantiate_and_link(key, payload, plen, keyring); + ret = __key_instantiate_and_link(key, payload, plen, keyring, NULL); if (ret < 0) { key_put(key); key = ERR_PTR(ret); @@ -841,12 +841,9 @@ int key_update(struct key *key, const void *payload, size_t plen) down_write(&key->sem); ret = key->type->update(key, payload, plen); - if (ret == 0) { + if (ret == 0) /* updating a negative key instantiates it */ - write_lock(&key->lock); - key->flags &= ~KEY_FLAG_NEGATIVE; - write_unlock(&key->lock); - } + clear_bit(KEY_FLAG_NEGATIVE, &key->flags); up_write(&key->sem); } @@ -892,10 +889,7 @@ struct key *key_duplicate(struct key *source, const char *desc) goto error2; atomic_inc(&key->user->nikeys); - - write_lock(&key->lock); - key->flags |= KEY_FLAG_INSTANTIATED; - write_unlock(&key->lock); + set_bit(KEY_FLAG_INSTANTIATED, &key->flags); error_k: up_read(&key_types_sem); @@ -922,9 +916,7 @@ void key_revoke(struct key *key) /* make sure no one's trying to change or use the key when we mark * it */ down_write(&key->sem); - write_lock(&key->lock); - key->flags |= KEY_FLAG_REVOKED; - write_unlock(&key->lock); + set_bit(KEY_FLAG_REVOKED, &key->flags); up_write(&key->sem); } /* end key_revoke() */ @@ -975,24 +967,33 @@ void unregister_key_type(struct key_type *ktype) /* withdraw the key type */ list_del_init(&ktype->link); - /* need to withdraw all keys of this type */ + /* mark all the keys of this type dead */ spin_lock(&key_serial_lock); for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) { key = rb_entry(_n, struct key, serial_node); - if (key->type != ktype) - continue; + if (key->type == ktype) + key->type = &key_type_dead; + } + + spin_unlock(&key_serial_lock); + + /* make sure everyone revalidates their keys */ + synchronize_rcu(); - write_lock(&key->lock); - key->type = &key_type_dead; - write_unlock(&key->lock); + /* we should now be able to destroy the payloads of all the keys of + * this type with impunity */ + spin_lock(&key_serial_lock); + + for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) { + key = rb_entry(_n, struct key, serial_node); - /* there shouldn't be anyone looking at the description or - * payload now */ - if (ktype->destroy) - ktype->destroy(key); - memset(&key->payload, 0xbd, sizeof(key->payload)); + if (key->type == ktype) { + if (ktype->destroy) + ktype->destroy(key); + memset(&key->payload, 0xbd, sizeof(key->payload)); + } } spin_unlock(&key_serial_lock); @@ -1037,4 +1038,5 @@ void __init key_init(void) /* 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 dc0011b..fea2628 100644 --- a/security/keys/keyctl.c +++ b/security/keys/keyctl.c @@ -1,6 +1,6 @@ /* keyctl.c: userspace keyctl operations * - * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. + * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or @@ -49,6 +49,13 @@ asmlinkage long sys_add_key(const char __user *_type, goto error; type[31] = '\0'; + if (!type[0]) + goto error; + + ret = -EPERM; + if (type[0] == '.') + goto error; + ret = -EFAULT; dlen = strnlen_user(_description, PAGE_SIZE - 1); if (dlen <= 0) @@ -82,7 +89,7 @@ asmlinkage long sys_add_key(const char __user *_type, } /* find the target keyring (which must be writable) */ - keyring = lookup_user_key(ringid, 1, 0, KEY_WRITE); + keyring = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE); if (IS_ERR(keyring)) { ret = PTR_ERR(keyring); goto error3; @@ -181,7 +188,7 @@ asmlinkage long sys_request_key(const char __user *_type, /* get the destination keyring if specified */ dest = NULL; if (destringid) { - dest = lookup_user_key(destringid, 1, 0, KEY_WRITE); + dest = lookup_user_key(NULL, destringid, 1, 0, KEY_WRITE); if (IS_ERR(dest)) { ret = PTR_ERR(dest); goto error3; @@ -196,23 +203,15 @@ asmlinkage long sys_request_key(const char __user *_type, } /* do the search */ - key = request_key(ktype, description, callout_info); + key = request_key_and_link(ktype, description, callout_info, dest); if (IS_ERR(key)) { ret = PTR_ERR(key); goto error5; } - /* link the resulting key to the destination keyring */ - if (dest) { - ret = key_link(dest, key); - if (ret < 0) - goto error6; - } - ret = key->serial; - error6: - key_put(key); + key_put(key); error5: key_type_put(ktype); error4: @@ -237,7 +236,7 @@ long keyctl_get_keyring_ID(key_serial_t id, int create) struct key *key; long ret; - key = lookup_user_key(id, create, 0, KEY_SEARCH); + key = lookup_user_key(NULL, id, create, 0, KEY_SEARCH); if (IS_ERR(key)) { ret = PTR_ERR(key); goto error; @@ -324,7 +323,7 @@ long keyctl_update_key(key_serial_t id, } /* find the target key (which must be writable) */ - key = lookup_user_key(id, 0, 0, KEY_WRITE); + key = lookup_user_key(NULL, id, 0, 0, KEY_WRITE); if (IS_ERR(key)) { ret = PTR_ERR(key); goto error2; @@ -352,7 +351,7 @@ long keyctl_revoke_key(key_serial_t id) struct key *key; long ret; - key = lookup_user_key(id, 0, 0, KEY_WRITE); + key = lookup_user_key(NULL, id, 0, 0, KEY_WRITE); if (IS_ERR(key)) { ret = PTR_ERR(key); goto error; @@ -378,7 +377,7 @@ long keyctl_keyring_clear(key_serial_t ringid) struct key *keyring; long ret; - keyring = lookup_user_key(ringid, 1, 0, KEY_WRITE); + keyring = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE); if (IS_ERR(keyring)) { ret = PTR_ERR(keyring); goto error; @@ -404,13 +403,13 @@ long keyctl_keyring_link(key_serial_t id, key_serial_t ringid) struct key *keyring, *key; long ret; - keyring = lookup_user_key(ringid, 1, 0, KEY_WRITE); + keyring = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE); if (IS_ERR(keyring)) { ret = PTR_ERR(keyring); goto error; } - key = lookup_user_key(id, 1, 0, KEY_LINK); + key = lookup_user_key(NULL, id, 1, 0, KEY_LINK); if (IS_ERR(key)) { ret = PTR_ERR(key); goto error2; @@ -438,13 +437,13 @@ long keyctl_keyring_unlink(key_serial_t id, key_serial_t ringid) struct key *keyring, *key; long ret; - keyring = lookup_user_key(ringid, 0, 0, KEY_WRITE); + keyring = lookup_user_key(NULL, ringid, 0, 0, KEY_WRITE); if (IS_ERR(keyring)) { ret = PTR_ERR(keyring); goto error; } - key = lookup_user_key(id, 0, 0, 0); + key = lookup_user_key(NULL, id, 0, 0, 0); if (IS_ERR(key)) { ret = PTR_ERR(key); goto error2; @@ -475,16 +474,29 @@ long keyctl_describe_key(key_serial_t keyid, char __user *buffer, size_t buflen) { - struct key *key; + struct key *key, *instkey; char *tmpbuf; long ret; - key = lookup_user_key(keyid, 0, 1, KEY_VIEW); + key = lookup_user_key(NULL, keyid, 0, 1, KEY_VIEW); if (IS_ERR(key)) { + /* viewing a key under construction is permitted if we have the + * authorisation token handy */ + if (PTR_ERR(key) == -EACCES) { + instkey = key_get_instantiation_authkey(keyid); + if (!IS_ERR(instkey)) { + key_put(instkey); + key = lookup_user_key(NULL, keyid, 0, 1, 0); + if (!IS_ERR(key)) + goto okay; + } + } + ret = PTR_ERR(key); goto error; } +okay: /* calculate how much description we're going to return */ ret = -ENOMEM; tmpbuf = kmalloc(PAGE_SIZE, GFP_KERNEL); @@ -568,7 +580,7 @@ long keyctl_keyring_search(key_serial_t ringid, goto error2; /* get the keyring at which to begin the search */ - keyring = lookup_user_key(ringid, 0, 0, KEY_SEARCH); + keyring = lookup_user_key(NULL, ringid, 0, 0, KEY_SEARCH); if (IS_ERR(keyring)) { ret = PTR_ERR(keyring); goto error2; @@ -577,7 +589,7 @@ long keyctl_keyring_search(key_serial_t ringid, /* get the destination keyring if specified */ dest = NULL; if (destringid) { - dest = lookup_user_key(destringid, 1, 0, KEY_WRITE); + dest = lookup_user_key(NULL, destringid, 1, 0, KEY_WRITE); if (IS_ERR(dest)) { ret = PTR_ERR(dest); goto error3; @@ -656,24 +668,23 @@ long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen) long ret; /* find the key first */ - key = lookup_user_key(keyid, 0, 0, 0); + key = lookup_user_key(NULL, keyid, 0, 0, 0); if (!IS_ERR(key)) { /* see if we can read it directly */ if (key_permission(key, KEY_READ)) goto can_read_key; - /* can't; see if it's searchable from this process's - * keyrings */ - ret = -ENOKEY; - if (key_permission(key, KEY_SEARCH)) { - /* okay - we do have search permission on the key - * itself, but do we have the key? */ - skey = search_process_keyrings_aux(key->type, key, - keyctl_read_key_same); - if (!IS_ERR(skey)) - goto can_read_key2; - } - + /* we can't; see if it's searchable from this process's + * keyrings + * - we automatically take account of the fact that it may be + * dangling off an instantiation key + */ + skey = search_process_keyrings(key->type, key, + keyctl_read_key_same, current); + if (!IS_ERR(skey)) + goto can_read_key2; + + ret = PTR_ERR(skey); goto error2; } @@ -719,7 +730,7 @@ 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 = lookup_user_key(id, 1, 1, 0); + key = lookup_user_key(NULL, id, 1, 1, 0); if (IS_ERR(key)) { ret = PTR_ERR(key); goto error; @@ -728,7 +739,6 @@ long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid) /* make the changes with the locks held to prevent chown/chown races */ ret = -EACCES; down_write(&key->sem); - write_lock(&key->lock); if (!capable(CAP_SYS_ADMIN)) { /* only the sysadmin can chown a key to some other UID */ @@ -755,7 +765,6 @@ long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid) ret = 0; no_access: - write_unlock(&key->lock); up_write(&key->sem); key_put(key); error: @@ -778,32 +787,25 @@ long keyctl_setperm_key(key_serial_t id, key_perm_t perm) if (perm & ~(KEY_USR_ALL | KEY_GRP_ALL | KEY_OTH_ALL)) goto error; - key = lookup_user_key(id, 1, 1, 0); + key = lookup_user_key(NULL, id, 1, 1, 0); if (IS_ERR(key)) { ret = PTR_ERR(key); goto error; } - /* make the changes with the locks held to prevent chown/chmod - * races */ + /* make the changes with the locks held to prevent chown/chmod races */ ret = -EACCES; down_write(&key->sem); - write_lock(&key->lock); - /* if we're not the sysadmin, we can only chmod a key that we - * own */ - if (!capable(CAP_SYS_ADMIN) && key->uid != current->fsuid) - goto no_access; - - /* changing the permissions mask */ - key->perm = perm; - ret = 0; + /* if we're not the sysadmin, we can only change a key that we own */ + if (capable(CAP_SYS_ADMIN) || key->uid == current->fsuid) { + key->perm = perm; + ret = 0; + } - no_access: - write_unlock(&key->lock); up_write(&key->sem); key_put(key); - error: +error: return ret; } /* end keyctl_setperm_key() */ @@ -818,7 +820,8 @@ long keyctl_instantiate_key(key_serial_t id, size_t plen, key_serial_t ringid) { - struct key *key, *keyring; + struct request_key_auth *rka; + struct key *instkey, *keyring; void *payload; long ret; @@ -840,18 +843,21 @@ long keyctl_instantiate_key(key_serial_t id, goto error2; } - /* find the target key (which must be writable) */ - key = lookup_user_key(id, 0, 1, KEY_WRITE); - if (IS_ERR(key)) { - ret = PTR_ERR(key); + /* find the instantiation authorisation key */ + instkey = key_get_instantiation_authkey(id); + if (IS_ERR(instkey)) { + ret = PTR_ERR(instkey); goto error2; } - /* find the destination keyring if present (which must also be - * writable) */ + rka = instkey->payload.data; + + /* find the destination keyring amongst those belonging to the + * requesting task */ keyring = NULL; if (ringid) { - keyring = lookup_user_key(ringid, 1, 0, KEY_WRITE); + keyring = lookup_user_key(rka->context, ringid, 1, 0, + KEY_WRITE); if (IS_ERR(keyring)) { ret = PTR_ERR(keyring); goto error3; @@ -859,11 +865,12 @@ long keyctl_instantiate_key(key_serial_t id, } /* instantiate the key and link it into a keyring */ - ret = key_instantiate_and_link(key, payload, plen, keyring); + ret = key_instantiate_and_link(rka->target_key, payload, plen, + keyring, instkey); key_put(keyring); error3: - key_put(key); + key_put(instkey); error2: kfree(payload); error: @@ -878,21 +885,24 @@ long keyctl_instantiate_key(key_serial_t id, */ long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid) { - struct key *key, *keyring; + struct request_key_auth *rka; + struct key *instkey, *keyring; long ret; - /* find the target key (which must be writable) */ - key = lookup_user_key(id, 0, 1, KEY_WRITE); - if (IS_ERR(key)) { - ret = PTR_ERR(key); + /* find the instantiation authorisation key */ + instkey = key_get_instantiation_authkey(id); + if (IS_ERR(instkey)) { + ret = PTR_ERR(instkey); goto error; } + rka = instkey->payload.data; + /* find the destination keyring if present (which must also be * writable) */ keyring = NULL; if (ringid) { - keyring = lookup_user_key(ringid, 1, 0, KEY_WRITE); + keyring = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE); if (IS_ERR(keyring)) { ret = PTR_ERR(keyring); goto error2; @@ -900,11 +910,11 @@ long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid) } /* instantiate the key and link it into a keyring */ - ret = key_negate_and_link(key, timeout, keyring); + ret = key_negate_and_link(rka->target_key, timeout, keyring, instkey); key_put(keyring); error2: - key_put(key); + key_put(instkey); error: return ret; @@ -912,6 +922,44 @@ long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid) /*****************************************************************************/ /* + * set the default keyring in which request_key() will cache keys + * - return the old setting + */ +long keyctl_set_reqkey_keyring(int reqkey_defl) +{ + int ret; + + switch (reqkey_defl) { + case KEY_REQKEY_DEFL_THREAD_KEYRING: + ret = install_thread_keyring(current); + if (ret < 0) + return ret; + goto set; + + case KEY_REQKEY_DEFL_PROCESS_KEYRING: + ret = install_process_keyring(current); + if (ret < 0) + return ret; + + case KEY_REQKEY_DEFL_DEFAULT: + case KEY_REQKEY_DEFL_SESSION_KEYRING: + case KEY_REQKEY_DEFL_USER_KEYRING: + case KEY_REQKEY_DEFL_USER_SESSION_KEYRING: + set: + current->jit_keyring = reqkey_defl; + + case KEY_REQKEY_DEFL_NO_CHANGE: + return current->jit_keyring; + + case KEY_REQKEY_DEFL_GROUP_KEYRING: + default: + return -EINVAL; + } + +} /* end keyctl_set_reqkey_keyring() */ + +/*****************************************************************************/ +/* * the key control system call */ asmlinkage long sys_keyctl(int option, unsigned long arg2, unsigned long arg3, @@ -980,6 +1028,9 @@ asmlinkage long sys_keyctl(int option, unsigned long arg2, unsigned long arg3, (unsigned) arg3, (key_serial_t) arg4); + case KEYCTL_SET_REQKEY_KEYRING: + return keyctl_set_reqkey_keyring(arg2); + default: return -EOPNOTSUPP; } diff --git a/security/keys/keyring.c b/security/keys/keyring.c index e2ab4f8..90a551e 100644 --- a/security/keys/keyring.c +++ b/security/keys/keyring.c @@ -1,6 +1,6 @@ /* keyring.c: keyring handling * - * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. + * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or @@ -132,10 +132,17 @@ static int keyring_duplicate(struct key *keyring, const struct key *source) (PAGE_SIZE - sizeof(*klist)) / sizeof(struct key); ret = 0; - sklist = source->payload.subscriptions; - if (sklist && sklist->nkeys > 0) { + /* find out how many keys are currently linked */ + rcu_read_lock(); + sklist = rcu_dereference(source->payload.subscriptions); + max = 0; + if (sklist) max = sklist->nkeys; + rcu_read_unlock(); + + /* allocate a new payload and stuff load with key links */ + if (max > 0) { BUG_ON(max > limit); max = (max + 3) & ~3; @@ -148,6 +155,10 @@ static int keyring_duplicate(struct key *keyring, const struct key *source) if (!klist) goto error; + /* set links */ + rcu_read_lock(); + sklist = rcu_dereference(source->payload.subscriptions); + klist->maxkeys = max; klist->nkeys = sklist->nkeys; memcpy(klist->keys, @@ -157,7 +168,9 @@ static int keyring_duplicate(struct key *keyring, const struct key *source) for (loop = klist->nkeys - 1; loop >= 0; loop--) atomic_inc(&klist->keys[loop]->usage); - keyring->payload.subscriptions = klist; + rcu_read_unlock(); + + rcu_assign_pointer(keyring->payload.subscriptions, klist); ret = 0; } @@ -192,7 +205,7 @@ static void keyring_destroy(struct key *keyring) write_unlock(&keyring_name_lock); } - klist = keyring->payload.subscriptions; + klist = rcu_dereference(keyring->payload.subscriptions); if (klist) { for (loop = klist->nkeys - 1; loop >= 0; loop--) key_put(klist->keys[loop]); @@ -216,17 +229,20 @@ static void keyring_describe(const struct key *keyring, struct seq_file *m) seq_puts(m, "[anon]"); } - klist = keyring->payload.subscriptions; + rcu_read_lock(); + klist = rcu_dereference(keyring->payload.subscriptions); if (klist) seq_printf(m, ": %u/%u", klist->nkeys, klist->maxkeys); else seq_puts(m, ": empty"); + rcu_read_unlock(); } /* end keyring_describe() */ /*****************************************************************************/ /* * read a list of key IDs from the keyring's contents + * - the keyring's semaphore is read-locked */ static long keyring_read(const struct key *keyring, char __user *buffer, size_t buflen) @@ -237,7 +253,7 @@ static long keyring_read(const struct key *keyring, int loop, ret; ret = 0; - klist = keyring->payload.subscriptions; + klist = rcu_dereference(keyring->payload.subscriptions); if (klist) { /* calculate how much data we could return */ @@ -292,7 +308,7 @@ struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid, uid, gid, KEY_USR_ALL, not_in_quota); if (!IS_ERR(keyring)) { - ret = key_instantiate_and_link(keyring, NULL, 0, dest); + ret = key_instantiate_and_link(keyring, NULL, 0, dest, NULL); if (ret < 0) { key_put(keyring); keyring = ERR_PTR(ret); @@ -310,17 +326,18 @@ struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid, * - we only find keys on which we have search permission * - we use the supplied match function to see if the description (or other * feature of interest) matches - * - we readlock the keyrings as we search down the tree + * - we rely on RCU to prevent the keyring lists from disappearing on us * - we return -EAGAIN if we didn't find any matching key * - we return -ENOKEY if we only found negative matching keys */ struct key *keyring_search_aux(struct key *keyring, + struct task_struct *context, struct key_type *type, const void *description, key_match_func_t match) { struct { - struct key *keyring; + struct keyring_list *keylist; int kix; } stack[KEYRING_SEARCH_MAX_DEPTH]; @@ -328,13 +345,15 @@ struct key *keyring_search_aux(struct key *keyring, struct timespec now; struct key *key; long err; - int sp, psp, kix; + int sp, kix; key_check(keyring); + rcu_read_lock(); + /* top keyring must have search permission to begin the search */ key = ERR_PTR(-EACCES); - if (!key_permission(keyring, KEY_SEARCH)) + if (!key_task_permission(keyring, context, KEY_SEARCH)) goto error; key = ERR_PTR(-ENOTDIR); @@ -347,11 +366,10 @@ struct key *keyring_search_aux(struct key *keyring, /* start processing a new keyring */ descend: - read_lock(&keyring->lock); - if (keyring->flags & KEY_FLAG_REVOKED) + if (test_bit(KEY_FLAG_REVOKED, &keyring->flags)) goto not_this_keyring; - keylist = keyring->payload.subscriptions; + keylist = rcu_dereference(keyring->payload.subscriptions); if (!keylist) goto not_this_keyring; @@ -364,7 +382,7 @@ struct key *keyring_search_aux(struct key *keyring, continue; /* skip revoked keys and expired keys */ - if (key->flags & KEY_FLAG_REVOKED) + if (test_bit(KEY_FLAG_REVOKED, &key->flags)) continue; if (key->expiry && now.tv_sec >= key->expiry) @@ -375,11 +393,11 @@ struct key *keyring_search_aux(struct key *keyring, continue; /* key must have search permissions */ - if (!key_permission(key, KEY_SEARCH)) + if (!key_task_permission(key, context, KEY_SEARCH)) continue; /* we set a different error code if we find a negative key */ - if (key->flags & KEY_FLAG_NEGATIVE) { + if (test_bit(KEY_FLAG_NEGATIVE, &key->flags)) { err = -ENOKEY; continue; } @@ -390,48 +408,37 @@ struct key *keyring_search_aux(struct key *keyring, /* search through the keyrings nested in this one */ kix = 0; ascend: - while (kix < keylist->nkeys) { + for (; kix < keylist->nkeys; kix++) { key = keylist->keys[kix]; if (key->type != &key_type_keyring) - goto next; + continue; /* recursively search nested keyrings * - only search keyrings for which we have search permission */ if (sp >= KEYRING_SEARCH_MAX_DEPTH) - goto next; - - if (!key_permission(key, KEY_SEARCH)) - goto next; + continue; - /* evade loops in the keyring tree */ - for (psp = 0; psp < sp; psp++) - if (stack[psp].keyring == keyring) - goto next; + if (!key_task_permission(key, context, KEY_SEARCH)) + continue; /* stack the current position */ - stack[sp].keyring = keyring; + stack[sp].keylist = keylist; stack[sp].kix = kix; sp++; /* begin again with the new keyring */ keyring = key; goto descend; - - next: - kix++; } /* the keyring we're looking at was disqualified or didn't contain a * matching key */ not_this_keyring: - read_unlock(&keyring->lock); - if (sp > 0) { /* resume the processing of a keyring higher up in the tree */ sp--; - keyring = stack[sp].keyring; - keylist = keyring->payload.subscriptions; + keylist = stack[sp].keylist; kix = stack[sp].kix + 1; goto ascend; } @@ -442,16 +449,9 @@ struct key *keyring_search_aux(struct key *keyring, /* we found a viable match */ found: atomic_inc(&key->usage); - read_unlock(&keyring->lock); - - /* unwind the keyring stack */ - while (sp > 0) { - sp--; - read_unlock(&stack[sp].keyring->lock); - } - key_check(key); error: + rcu_read_unlock(); return key; } /* end keyring_search_aux() */ @@ -469,7 +469,11 @@ struct key *keyring_search(struct key *keyring, struct key_type *type, const char *description) { - return keyring_search_aux(keyring, type, description, type->match); + if (!type->match) + return ERR_PTR(-ENOKEY); + + return keyring_search_aux(keyring, current, + type, description, type->match); } /* end keyring_search() */ @@ -489,15 +493,18 @@ struct key *__keyring_search_one(struct key *keyring, struct key *key; int loop; - klist = keyring->payload.subscriptions; + rcu_read_lock(); + + klist = rcu_dereference(keyring->payload.subscriptions); if (klist) { for (loop = 0; loop < klist->nkeys; loop++) { key = klist->keys[loop]; if (key->type == ktype && - key->type->match(key, description) && + (!key->type->match || + key->type->match(key, description)) && key_permission(key, perm) && - !(key->flags & KEY_FLAG_REVOKED) + !test_bit(KEY_FLAG_REVOKED, &key->flags) ) goto found; } @@ -509,12 +516,58 @@ struct key *__keyring_search_one(struct key *keyring, found: atomic_inc(&key->usage); error: + rcu_read_unlock(); return key; } /* end __keyring_search_one() */ /*****************************************************************************/ /* + * search for an instantiation authorisation key matching a target key + * - the RCU read lock must be held by the caller + * - a target_id of zero specifies any valid token + */ +struct key *keyring_search_instkey(struct key *keyring, + key_serial_t target_id) +{ + struct request_key_auth *rka; + struct keyring_list *klist; + struct key *instkey; + int loop; + + klist = rcu_dereference(keyring->payload.subscriptions); + if (klist) { + for (loop = 0; loop < klist->nkeys; loop++) { + instkey = klist->keys[loop]; + + if (instkey->type != &key_type_request_key_auth) + continue; + + rka = instkey->payload.data; + if (target_id && rka->target_key->serial != target_id) + continue; + + /* the auth key is revoked during instantiation */ + if (!test_bit(KEY_FLAG_REVOKED, &instkey->flags)) + goto found; + + instkey = ERR_PTR(-EKEYREVOKED); + goto error; + } + } + + instkey = ERR_PTR(-EACCES); + goto error; + +found: + atomic_inc(&instkey->usage); +error: + return instkey; + +} /* end keyring_search_instkey() */ + +/*****************************************************************************/ +/* * find a keyring with the specified name * - all named keyrings are searched * - only find keyrings with search permission for the process @@ -540,7 +593,7 @@ struct key *find_keyring_by_name(const char *name, key_serial_t bound) &keyring_name_hash[bucket], type_data.link ) { - if (keyring->flags & KEY_FLAG_REVOKED) + if (test_bit(KEY_FLAG_REVOKED, &keyring->flags)) continue; if (strcmp(keyring->description, name) != 0) @@ -579,7 +632,7 @@ struct key *find_keyring_by_name(const char *name, key_serial_t bound) static int keyring_detect_cycle(struct key *A, struct key *B) { struct { - struct key *subtree; + struct keyring_list *keylist; int kix; } stack[KEYRING_SEARCH_MAX_DEPTH]; @@ -587,20 +640,21 @@ static int keyring_detect_cycle(struct key *A, struct key *B) struct key *subtree, *key; int sp, kix, ret; + rcu_read_lock(); + ret = -EDEADLK; if (A == B) - goto error; + goto cycle_detected; subtree = B; sp = 0; /* start processing a new keyring */ descend: - read_lock(&subtree->lock); - if (subtree->flags & KEY_FLAG_REVOKED) + if (test_bit(KEY_FLAG_REVOKED, &subtree->flags)) goto not_this_keyring; - keylist = subtree->payload.subscriptions; + keylist = rcu_dereference(subtree->payload.subscriptions); if (!keylist) goto not_this_keyring; kix = 0; @@ -619,7 +673,7 @@ static int keyring_detect_cycle(struct key *A, struct key *B) goto too_deep; /* stack the current position */ - stack[sp].subtree = subtree; + stack[sp].keylist = keylist; stack[sp].kix = kix; sp++; @@ -632,13 +686,10 @@ static int keyring_detect_cycle(struct key *A, struct key *B) /* the keyring we're looking at was disqualified or didn't contain a * matching key */ not_this_keyring: - read_unlock(&subtree->lock); - if (sp > 0) { /* resume the checking of a keyring higher up in the tree */ sp--; - subtree = stack[sp].subtree; - keylist = subtree->payload.subscriptions; + keylist = stack[sp].keylist; kix = stack[sp].kix + 1; goto ascend; } @@ -646,30 +697,36 @@ static int keyring_detect_cycle(struct key *A, struct key *B) ret = 0; /* no cycles detected */ error: + rcu_read_unlock(); return ret; too_deep: ret = -ELOOP; - goto error_unwind; + goto error; + cycle_detected: ret = -EDEADLK; - error_unwind: - read_unlock(&subtree->lock); - - /* unwind the keyring stack */ - while (sp > 0) { - sp--; - read_unlock(&stack[sp].subtree->lock); - } - goto error; } /* end keyring_detect_cycle() */ /*****************************************************************************/ /* + * dispose of a keyring list after the RCU grace period + */ +static void keyring_link_rcu_disposal(struct rcu_head *rcu) +{ + struct keyring_list *klist = + container_of(rcu, struct keyring_list, rcu); + + kfree(klist); + +} /* end keyring_link_rcu_disposal() */ + +/*****************************************************************************/ +/* * link a key into to a keyring - * - must be called with the keyring's semaphore held + * - must be called with the keyring's semaphore write-locked */ int __key_link(struct key *keyring, struct key *key) { @@ -679,7 +736,7 @@ int __key_link(struct key *keyring, struct key *key) int ret; ret = -EKEYREVOKED; - if (keyring->flags & KEY_FLAG_REVOKED) + if (test_bit(KEY_FLAG_REVOKED, &keyring->flags)) goto error; ret = -ENOTDIR; @@ -710,9 +767,10 @@ int __key_link(struct key *keyring, struct key *key) /* there's sufficient slack space to add directly */ atomic_inc(&key->usage); - write_lock(&keyring->lock); - klist->keys[klist->nkeys++] = key; - write_unlock(&keyring->lock); + klist->keys[klist->nkeys] = key; + smp_wmb(); + klist->nkeys++; + smp_wmb(); ret = 0; } @@ -723,6 +781,8 @@ int __key_link(struct key *keyring, struct key *key) max += klist->maxkeys; ret = -ENFILE; + if (max > 65535) + goto error3; size = sizeof(*klist) + sizeof(*key) * max; if (size > PAGE_SIZE) goto error3; @@ -743,14 +803,13 @@ int __key_link(struct key *keyring, struct key *key) /* add the key into the new space */ atomic_inc(&key->usage); - - write_lock(&keyring->lock); - keyring->payload.subscriptions = nklist; nklist->keys[nklist->nkeys++] = key; - write_unlock(&keyring->lock); + + rcu_assign_pointer(keyring->payload.subscriptions, nklist); /* dispose of the old keyring list */ - kfree(klist); + if (klist) + call_rcu(&klist->rcu, keyring_link_rcu_disposal); ret = 0; } @@ -791,11 +850,26 @@ EXPORT_SYMBOL(key_link); /*****************************************************************************/ /* + * dispose of a keyring list after the RCU grace period, freeing the unlinked + * key + */ +static void keyring_unlink_rcu_disposal(struct rcu_head *rcu) +{ + struct keyring_list *klist = + container_of(rcu, struct keyring_list, rcu); + + key_put(klist->keys[klist->delkey]); + kfree(klist); + +} /* end keyring_unlink_rcu_disposal() */ + +/*****************************************************************************/ +/* * unlink the first link to a key from a keyring */ int key_unlink(struct key *keyring, struct key *key) { - struct keyring_list *klist; + struct keyring_list *klist, *nklist; int loop, ret; key_check(keyring); @@ -819,31 +893,45 @@ int key_unlink(struct key *keyring, struct key *key) ret = -ENOENT; goto error; - key_is_present: +key_is_present: + /* we need to copy the key list for RCU purposes */ + nklist = kmalloc(sizeof(*klist) + sizeof(*key) * klist->maxkeys, + GFP_KERNEL); + if (!nklist) + goto nomem; + nklist->maxkeys = klist->maxkeys; + nklist->nkeys = klist->nkeys - 1; + + if (loop > 0) + memcpy(&nklist->keys[0], + &klist->keys[0], + loop * sizeof(klist->keys[0])); + + if (loop < nklist->nkeys) + memcpy(&nklist->keys[loop], + &klist->keys[loop + 1], + (nklist->nkeys - loop) * sizeof(klist->keys[0])); + /* adjust the user's quota */ key_payload_reserve(keyring, keyring->datalen - KEYQUOTA_LINK_BYTES); - /* shuffle down the key pointers - * - it might be worth shrinking the allocated memory, but that runs - * the risk of ENOMEM as we would have to copy - */ - write_lock(&keyring->lock); + rcu_assign_pointer(keyring->payload.subscriptions, nklist); - klist->nkeys--; - if (loop < klist->nkeys) - memcpy(&klist->keys[loop], - &klist->keys[loop + 1], - (klist->nkeys - loop) * sizeof(struct key *)); + up_write(&keyring->sem); - write_unlock(&keyring->lock); + /* schedule for later cleanup */ + klist->delkey = loop; + call_rcu(&klist->rcu, keyring_unlink_rcu_disposal); - up_write(&keyring->sem); - key_put(key); ret = 0; - error: +error: return ret; +nomem: + ret = -ENOMEM; + up_write(&keyring->sem); + goto error; } /* end key_unlink() */ @@ -851,13 +939,32 @@ EXPORT_SYMBOL(key_unlink); /*****************************************************************************/ /* + * dispose of a keyring list after the RCU grace period, releasing the keys it + * links to + */ +static void keyring_clear_rcu_disposal(struct rcu_head *rcu) +{ + struct keyring_list *klist; + int loop; + + klist = container_of(rcu, struct keyring_list, rcu); + + for (loop = klist->nkeys - 1; loop >= 0; loop--) + key_put(klist->keys[loop]); + + kfree(klist); + +} /* end keyring_clear_rcu_disposal() */ + +/*****************************************************************************/ +/* * clear the specified process keyring * - implements keyctl(KEYCTL_CLEAR) */ int keyring_clear(struct key *keyring) { struct keyring_list *klist; - int loop, ret; + int ret; ret = -ENOTDIR; if (keyring->type == &key_type_keyring) { @@ -870,20 +977,15 @@ int keyring_clear(struct key *keyring) key_payload_reserve(keyring, sizeof(struct keyring_list)); - write_lock(&keyring->lock); - keyring->payload.subscriptions = NULL; - write_unlock(&keyring->lock); + rcu_assign_pointer(keyring->payload.subscriptions, + NULL); } up_write(&keyring->sem); /* free the keys after the locks have been dropped */ - if (klist) { - for (loop = klist->nkeys - 1; loop >= 0; loop--) - key_put(klist->keys[loop]); - - kfree(klist); - } + if (klist) + call_rcu(&klist->rcu, keyring_clear_rcu_disposal); ret = 0; } diff --git a/security/keys/proc.c b/security/keys/proc.c index 91343b8..c55cf1f 100644 --- a/security/keys/proc.c +++ b/security/keys/proc.c @@ -140,7 +140,7 @@ static int proc_keys_show(struct seq_file *m, void *v) now = current_kernel_time(); - read_lock(&key->lock); + rcu_read_lock(); /* come up with a suitable timeout value */ if (key->expiry == 0) { @@ -164,14 +164,17 @@ static int proc_keys_show(struct seq_file *m, void *v) sprintf(xbuf, "%luw", timo / (60*60*24*7)); } +#define showflag(KEY, LETTER, FLAG) \ + (test_bit(FLAG, &(KEY)->flags) ? LETTER : '-') + seq_printf(m, "%08x %c%c%c%c%c%c %5d %4s %06x %5d %5d %-9.9s ", key->serial, - key->flags & KEY_FLAG_INSTANTIATED ? 'I' : '-', - key->flags & KEY_FLAG_REVOKED ? 'R' : '-', - key->flags & KEY_FLAG_DEAD ? 'D' : '-', - key->flags & KEY_FLAG_IN_QUOTA ? 'Q' : '-', - key->flags & KEY_FLAG_USER_CONSTRUCT ? 'U' : '-', - key->flags & KEY_FLAG_NEGATIVE ? 'N' : '-', + showflag(key, 'I', KEY_FLAG_INSTANTIATED), + showflag(key, 'R', KEY_FLAG_REVOKED), + showflag(key, 'D', KEY_FLAG_DEAD), + showflag(key, 'Q', KEY_FLAG_IN_QUOTA), + showflag(key, 'U', KEY_FLAG_USER_CONSTRUCT), + showflag(key, 'N', KEY_FLAG_NEGATIVE), atomic_read(&key->usage), xbuf, key->perm, @@ -179,11 +182,13 @@ static int proc_keys_show(struct seq_file *m, void *v) key->gid, key->type->name); +#undef showflag + if (key->type->describe) key->type->describe(key, m); seq_putc(m, '\n'); - read_unlock(&key->lock); + rcu_read_unlock(); return 0; diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c index 2eb0e47..9b0369c 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 * - * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. + * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or @@ -38,10 +38,9 @@ struct key root_user_keyring = { .serial = 2, .type = &key_type_keyring, .user = &root_key_user, - .lock = RW_LOCK_UNLOCKED, .sem = __RWSEM_INITIALIZER(root_user_keyring.sem), .perm = KEY_USR_ALL, - .flags = KEY_FLAG_INSTANTIATED, + .flags = 1 << KEY_FLAG_INSTANTIATED, .description = "_uid.0", #ifdef KEY_DEBUGGING .magic = KEY_DEBUG_MAGIC, @@ -54,10 +53,9 @@ struct key root_session_keyring = { .serial = 1, .type = &key_type_keyring, .user = &root_key_user, - .lock = RW_LOCK_UNLOCKED, .sem = __RWSEM_INITIALIZER(root_session_keyring.sem), .perm = KEY_USR_ALL, - .flags = KEY_FLAG_INSTANTIATED, + .flags = 1 << KEY_FLAG_INSTANTIATED, .description = "_uid_ses.0", #ifdef KEY_DEBUGGING .magic = KEY_DEBUG_MAGIC, @@ -167,7 +165,7 @@ int install_thread_keyring(struct task_struct *tsk) /* * make sure a process keyring is installed */ -static int install_process_keyring(struct task_struct *tsk) +int install_process_keyring(struct task_struct *tsk) { unsigned long flags; struct key *keyring; @@ -183,7 +181,7 @@ static int install_process_keyring(struct task_struct *tsk) goto error; } - /* attach or swap keyrings */ + /* attach keyring */ spin_lock_irqsave(&tsk->sighand->siglock, flags); if (!tsk->signal->process_keyring) { tsk->signal->process_keyring = keyring; @@ -229,12 +227,14 @@ static int install_session_keyring(struct task_struct *tsk, /* install the keyring */ spin_lock_irqsave(&tsk->sighand->siglock, flags); - old = tsk->signal->session_keyring; - tsk->signal->session_keyring = keyring; + old = rcu_dereference(tsk->signal->session_keyring); + rcu_assign_pointer(tsk->signal->session_keyring, keyring); spin_unlock_irqrestore(&tsk->sighand->siglock, flags); ret = 0; + /* we're using RCU on the pointer */ + synchronize_rcu(); key_put(old); error: return ret; @@ -247,8 +247,6 @@ static int install_session_keyring(struct task_struct *tsk, */ int copy_thread_group_keys(struct task_struct *tsk) { - unsigned long flags; - key_check(current->thread_group->session_keyring); key_check(current->thread_group->process_keyring); @@ -256,10 +254,10 @@ int copy_thread_group_keys(struct task_struct *tsk) tsk->signal->process_keyring = NULL; /* same session keyring */ - spin_lock_irqsave(¤t->sighand->siglock, flags); + rcu_read_lock(); tsk->signal->session_keyring = - key_get(current->signal->session_keyring); - spin_unlock_irqrestore(¤t->sighand->siglock, flags); + key_get(rcu_dereference(current->signal->session_keyring)); + rcu_read_unlock(); return 0; @@ -349,9 +347,7 @@ void key_fsuid_changed(struct task_struct *tsk) /* update the ownership of the thread keyring */ if (tsk->thread_keyring) { down_write(&tsk->thread_keyring->sem); - write_lock(&tsk->thread_keyring->lock); tsk->thread_keyring->uid = tsk->fsuid; - write_unlock(&tsk->thread_keyring->lock); up_write(&tsk->thread_keyring->sem); } @@ -366,9 +362,7 @@ void key_fsgid_changed(struct task_struct *tsk) /* update the ownership of the thread keyring */ if (tsk->thread_keyring) { down_write(&tsk->thread_keyring->sem); - write_lock(&tsk->thread_keyring->lock); tsk->thread_keyring->gid = tsk->fsgid; - write_unlock(&tsk->thread_keyring->lock); up_write(&tsk->thread_keyring->sem); } @@ -382,13 +376,13 @@ void key_fsgid_changed(struct task_struct *tsk) * - we return -EAGAIN if we didn't find any matching key * - we return -ENOKEY if we found only negative matching keys */ -struct key *search_process_keyrings_aux(struct key_type *type, - const void *description, - key_match_func_t match) +struct key *search_process_keyrings(struct key_type *type, + const void *description, + key_match_func_t match, + struct task_struct *context) { - struct task_struct *tsk = current; - unsigned long flags; - struct key *key, *ret, *err, *tmp; + struct request_key_auth *rka; + struct key *key, *ret, *err, *instkey; /* we want to return -EAGAIN or -ENOKEY if any of the keyrings were * searchable, but we failed to find a key or we found a negative key; @@ -402,9 +396,9 @@ struct key *search_process_keyrings_aux(struct key_type *type, err = ERR_PTR(-EAGAIN); /* search the thread keyring first */ - if (tsk->thread_keyring) { - key = keyring_search_aux(tsk->thread_keyring, type, - description, match); + if (context->thread_keyring) { + key = keyring_search_aux(context->thread_keyring, + context, type, description, match); if (!IS_ERR(key)) goto found; @@ -422,9 +416,9 @@ struct key *search_process_keyrings_aux(struct key_type *type, } /* search the process keyring second */ - if (tsk->signal->process_keyring) { - key = keyring_search_aux(tsk->signal->process_keyring, - type, description, match); + if (context->signal->process_keyring) { + key = keyring_search_aux(context->signal->process_keyring, + context, type, description, match); if (!IS_ERR(key)) goto found; @@ -441,52 +435,93 @@ struct key *search_process_keyrings_aux(struct key_type *type, } } - /* search the session keyring last */ - spin_lock_irqsave(&tsk->sighand->siglock, flags); + /* search the session keyring */ + if (context->signal->session_keyring) { + rcu_read_lock(); + key = keyring_search_aux( + rcu_dereference(context->signal->session_keyring), + context, type, description, match); + rcu_read_unlock(); - tmp = tsk->signal->session_keyring; - if (!tmp) - tmp = tsk->user->session_keyring; - atomic_inc(&tmp->usage); + if (!IS_ERR(key)) + goto found; - spin_unlock_irqrestore(&tsk->sighand->siglock, flags); + switch (PTR_ERR(key)) { + case -EAGAIN: /* no key */ + if (ret) + break; + case -ENOKEY: /* negative key */ + ret = key; + break; + default: + err = key; + break; + } + + /* if this process has a session keyring and that has an + * instantiation authorisation key in the bottom level, then we + * also search the keyrings of the process mentioned there */ + if (context != current) + goto no_key; + + rcu_read_lock(); + instkey = __keyring_search_one( + rcu_dereference(context->signal->session_keyring), + &key_type_request_key_auth, NULL, 0); + rcu_read_unlock(); + + if (IS_ERR(instkey)) + goto no_key; + + rka = instkey->payload.data; - key = keyring_search_aux(tmp, type, description, match); - key_put(tmp); - if (!IS_ERR(key)) - goto found; + key = search_process_keyrings(type, description, match, + rka->context); + key_put(instkey); - switch (PTR_ERR(key)) { - case -EAGAIN: /* no key */ - if (ret) + if (!IS_ERR(key)) + goto found; + + switch (PTR_ERR(key)) { + case -EAGAIN: /* no key */ + if (ret) + break; + case -ENOKEY: /* negative key */ + ret = key; break; - case -ENOKEY: /* negative key */ - ret = key; - break; - default: - err = key; - break; + default: + err = key; + break; + } + } + /* or search the user-session keyring */ + else { + key = keyring_search_aux(context->user->session_keyring, + context, type, description, match); + if (!IS_ERR(key)) + goto found; + + switch (PTR_ERR(key)) { + case -EAGAIN: /* no key */ + if (ret) + break; + case -ENOKEY: /* negative key */ + ret = key; + break; + default: + err = key; + break; + } } + +no_key: /* no key - decide on the error we're going to go for */ key = ret ? ret : err; - found: +found: return key; -} /* end search_process_keyrings_aux() */ - -/*****************************************************************************/ -/* - * search the process keyrings for the first matching key - * - we return -EAGAIN if we didn't find any matching key - * - we return -ENOKEY if we found only negative matching keys - */ -struct key *search_process_keyrings(struct key_type *type, - const char *description) -{ - return search_process_keyrings_aux(type, description, type->match); - } /* end search_process_keyrings() */ /*****************************************************************************/ @@ -495,72 +530,73 @@ struct key *search_process_keyrings(struct key_type *type, * - don't create special keyrings unless so requested * - partially constructed keys aren't found unless requested */ -struct key *lookup_user_key(key_serial_t id, int create, int partial, - key_perm_t perm) +struct key *lookup_user_key(struct task_struct *context, key_serial_t id, + int create, int partial, key_perm_t perm) { - struct task_struct *tsk = current; - unsigned long flags; struct key *key; int ret; + if (!context) + context = current; + key = ERR_PTR(-ENOKEY); switch (id) { case KEY_SPEC_THREAD_KEYRING: - if (!tsk->thread_keyring) { + if (!context->thread_keyring) { if (!create) goto error; - ret = install_thread_keyring(tsk); + ret = install_thread_keyring(context); if (ret < 0) { key = ERR_PTR(ret); goto error; } } - key = tsk->thread_keyring; + key = context->thread_keyring; atomic_inc(&key->usage); break; case KEY_SPEC_PROCESS_KEYRING: - if (!tsk->signal->process_keyring) { + if (!context->signal->process_keyring) { if (!create) goto error; - ret = install_process_keyring(tsk); + ret = install_process_keyring(context); if (ret < 0) { key = ERR_PTR(ret); goto error; } } - key = tsk->signal->process_keyring; + key = context->signal->process_keyring; atomic_inc(&key->usage); break; case KEY_SPEC_SESSION_KEYRING: - if (!tsk->signal->session_keyring) { + if (!context->signal->session_keyring) { /* always install a session keyring upon access if one * doesn't exist yet */ ret = install_session_keyring( - tsk, tsk->user->session_keyring); + context, context->user->session_keyring); if (ret < 0) goto error; } - spin_lock_irqsave(&tsk->sighand->siglock, flags); - key = tsk->signal->session_keyring; + rcu_read_lock(); + key = rcu_dereference(context->signal->session_keyring); atomic_inc(&key->usage); - spin_unlock_irqrestore(&tsk->sighand->siglock, flags); + rcu_read_unlock(); break; case KEY_SPEC_USER_KEYRING: - key = tsk->user->uid_keyring; + key = context->user->uid_keyring; atomic_inc(&key->usage); break; case KEY_SPEC_USER_SESSION_KEYRING: - key = tsk->user->session_keyring; + key = context->user->session_keyring; atomic_inc(&key->usage); break; @@ -580,7 +616,7 @@ struct key *lookup_user_key(key_serial_t id, int create, int partial, break; } - /* check the status and permissions */ + /* check the status */ if (perm) { ret = key_validate(key); if (ret < 0) @@ -588,11 +624,13 @@ struct key *lookup_user_key(key_serial_t id, int create, int partial, } ret = -EIO; - if (!partial && !(key->flags & KEY_FLAG_INSTANTIATED)) + if (!partial && !test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) goto invalid_key; + /* check the permissions */ ret = -EACCES; - if (!key_permission(key, perm)) + + if (!key_task_permission(key, context, perm)) goto invalid_key; error: @@ -615,7 +653,6 @@ struct key *lookup_user_key(key_serial_t id, int create, int partial, long join_session_keyring(const char *name) { struct task_struct *tsk = current; - unsigned long flags; struct key *keyring; long ret; @@ -625,9 +662,9 @@ long join_session_keyring(const char *name) if (ret < 0) goto error; - spin_lock_irqsave(&tsk->sighand->siglock, flags); - ret = tsk->signal->session_keyring->serial; - spin_unlock_irqrestore(&tsk->sighand->siglock, flags); + rcu_read_lock(); + ret = rcu_dereference(tsk->signal->session_keyring)->serial; + rcu_read_unlock(); goto error; } diff --git a/security/keys/request_key.c b/security/keys/request_key.c index 9705b1a..dfcd983 100644 --- a/security/keys/request_key.c +++ b/security/keys/request_key.c @@ -1,6 +1,6 @@ /* request_key.c: request a key from userspace * - * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. + * Copyright (C) 2004-5 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/sched.h> #include <linux/kmod.h> #include <linux/err.h> +#include <linux/keyctl.h> #include "internal.h" struct key_construction { @@ -27,18 +28,26 @@ DECLARE_WAIT_QUEUE_HEAD(request_key_conswq); /* * request userspace finish the construction of a key * - execute "/sbin/request-key <op> <key> <uid> <gid> <keyring> <keyring> <keyring> <info>" - * - if callout_info is an empty string, it'll be rendered as a "-" instead */ static int call_request_key(struct key *key, const char *op, const char *callout_info) { struct task_struct *tsk = current; - unsigned long flags; key_serial_t prkey, sskey; + struct key *session_keyring, *rkakey; char *argv[10], *envp[3], uid_str[12], gid_str[12]; char key_str[12], keyring_str[3][12]; - int i; + int ret, i; + + kenter("{%d},%s,%s", key->serial, op, callout_info); + + /* generate a new session keyring with an auth key in it */ + session_keyring = request_key_auth_new(key, &rkakey); + if (IS_ERR(session_keyring)) { + ret = PTR_ERR(session_keyring); + goto error; + } /* record the UID and GID */ sprintf(uid_str, "%d", current->fsuid); @@ -55,17 +64,17 @@ static int call_request_key(struct key *key, if (tsk->signal->process_keyring) prkey = tsk->signal->process_keyring->serial; - sskey = 0; - spin_lock_irqsave(&tsk->sighand->siglock, flags); - if (tsk->signal->session_keyring) - sskey = tsk->signal->session_keyring->serial; - spin_unlock_irqrestore(&tsk->sighand->siglock, flags); - + sprintf(keyring_str[1], "%d", prkey); - if (!sskey) + if (tsk->signal->session_keyring) { + rcu_read_lock(); + sskey = rcu_dereference(tsk->signal->session_keyring)->serial; + rcu_read_unlock(); + } + else { sskey = tsk->user->session_keyring->serial; + } - sprintf(keyring_str[1], "%d", prkey); sprintf(keyring_str[2], "%d", sskey); /* set up a minimal environment */ @@ -84,11 +93,20 @@ static int call_request_key(struct key *key, argv[i++] = keyring_str[0]; argv[i++] = keyring_str[1]; argv[i++] = keyring_str[2]; - argv[i++] = callout_info[0] ? (char *) callout_info : "-"; + argv[i++] = (char *) callout_info; argv[i] = NULL; /* do it */ - return call_usermodehelper(argv[0], argv, envp, 1); + ret = call_usermodehelper_keys(argv[0], argv, envp, session_keyring, 1); + + /* dispose of the special keys */ + key_revoke(rkakey); + key_put(rkakey); + key_put(session_keyring); + + error: + kleave(" = %d", ret); + return ret; } /* end call_request_key() */ @@ -105,7 +123,9 @@ static struct key *__request_key_construction(struct key_type *type, struct key_construction cons; struct timespec now; struct key *key; - int ret, negative; + int ret, negated; + + kenter("%s,%s,%s", type->name, description, callout_info); /* create a key and add it to the queue */ key = key_alloc(type, description, @@ -113,9 +133,7 @@ static struct key *__request_key_construction(struct key_type *type, if (IS_ERR(key)) goto alloc_failed; - write_lock(&key->lock); - key->flags |= KEY_FLAG_USER_CONSTRUCT; - write_unlock(&key->lock); + set_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags); cons.key = key; list_add_tail(&cons.link, &key->user->consq); @@ -130,7 +148,7 @@ static struct key *__request_key_construction(struct key_type *type, /* if the key wasn't instantiated, then we want to give an error */ ret = -ENOKEY; - if (!(key->flags & KEY_FLAG_INSTANTIATED)) + if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) goto request_failed; down_write(&key_construction_sem); @@ -139,12 +157,13 @@ static struct key *__request_key_construction(struct key_type *type, /* also give an error if the key was negatively instantiated */ check_not_negative: - if (key->flags & KEY_FLAG_NEGATIVE) { + if (test_bit(KEY_FLAG_NEGATIVE, &key->flags)) { key_put(key); key = ERR_PTR(-ENOKEY); } out: + kleave(" = %p", key); return key; request_failed: @@ -152,24 +171,23 @@ static struct key *__request_key_construction(struct key_type *type, * - remove from construction queue * - mark the key as dead */ - negative = 0; + negated = 0; down_write(&key_construction_sem); list_del(&cons.link); - write_lock(&key->lock); - key->flags &= ~KEY_FLAG_USER_CONSTRUCT; - /* check it didn't get instantiated between the check and the down */ - if (!(key->flags & KEY_FLAG_INSTANTIATED)) { - key->flags |= KEY_FLAG_INSTANTIATED | KEY_FLAG_NEGATIVE; - negative = 1; + if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) { + set_bit(KEY_FLAG_NEGATIVE, &key->flags); + set_bit(KEY_FLAG_INSTANTIATED, &key->flags); + negated = 1; } - write_unlock(&key->lock); + clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags); + up_write(&key_construction_sem); - if (!negative) + if (!negated) goto check_not_negative; /* surprisingly, the key got * instantiated */ @@ -178,13 +196,12 @@ static struct key *__request_key_construction(struct key_type *type, key->expiry = now.tv_sec + key_negative_timeout; if (current->signal->session_keyring) { - unsigned long flags; struct key *keyring; - spin_lock_irqsave(¤t->sighand->siglock, flags); - keyring = current->signal->session_keyring; + rcu_read_lock(); + keyring = rcu_dereference(current->signal->session_keyring); atomic_inc(&keyring->usage); - spin_unlock_irqrestore(¤t->sighand->siglock, flags); + rcu_read_unlock(); key_link(keyring, key); key_put(keyring); @@ -220,6 +237,9 @@ static struct key *request_key_construction(struct key_type *type, DECLARE_WAITQUEUE(myself, current); + kenter("%s,%s,{%d},%s", + type->name, description, user->uid, callout_info); + /* see if there's such a key under construction already */ down_write(&key_construction_sem); @@ -236,6 +256,7 @@ static struct key *request_key_construction(struct key_type *type, /* see about getting userspace to construct the key */ key = __request_key_construction(type, description, callout_info); error: + kleave(" = %p", key); return key; /* someone else has the same key under construction @@ -249,8 +270,10 @@ static struct key *request_key_construction(struct key_type *type, add_wait_queue(&request_key_conswq, &myself); for (;;) { - set_current_state(TASK_UNINTERRUPTIBLE); - if (!(ckey->flags & KEY_FLAG_USER_CONSTRUCT)) + set_current_state(TASK_INTERRUPTIBLE); + if (!test_bit(KEY_FLAG_USER_CONSTRUCT, &ckey->flags)) + break; + if (signal_pending(current)) break; schedule(); } @@ -271,21 +294,83 @@ static struct key *request_key_construction(struct key_type *type, /*****************************************************************************/ /* + * link a freshly minted key to an appropriate destination keyring + */ +static void request_key_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 = current->user->session_keyring; + break; + + case KEY_REQKEY_DEFL_USER_KEYRING: + dest_keyring = current->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(""); + +} /* end request_key_link() */ + +/*****************************************************************************/ +/* * 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 requested (supplementary info can be - * passed) + * - call out to userspace for a key if supplementary info was provided + * - cache the key in an appropriate keyring */ -struct key *request_key(struct key_type *type, - const char *description, - const char *callout_info) +struct key *request_key_and_link(struct key_type *type, + const char *description, + const char *callout_info, + struct key *dest_keyring) { struct key_user *user; struct key *key; + kenter("%s,%s,%s,%p", + type->name, description, callout_info, dest_keyring); + /* search all the process keyrings for a key */ - key = search_process_keyrings_aux(type, description, type->match); + key = search_process_keyrings(type, description, type->match, current); if (PTR_ERR(key) == -EAGAIN) { /* the search failed, but the keyrings were searchable, so we @@ -296,12 +381,13 @@ struct key *request_key(struct key_type *type, /* - get hold of the user's construction queue */ user = key_user_lookup(current->fsuid); - if (!user) { - key = ERR_PTR(-ENOMEM); - goto error; - } + if (!user) + goto nomem; + + do { + if (signal_pending(current)) + goto interrupted; - for (;;) { /* ask userspace (returns NULL if it waited on a key * being constructed) */ key = request_key_construction(type, description, @@ -311,18 +397,46 @@ struct key *request_key(struct key_type *type, /* someone else made the key we want, so we need to * search again as it might now be available to us */ - key = search_process_keyrings_aux(type, description, - type->match); - if (PTR_ERR(key) != -EAGAIN) - break; - } + key = search_process_keyrings(type, description, + type->match, current); + + } while (PTR_ERR(key) == -EAGAIN); key_user_put(user); + + /* link the new key into the appropriate keyring */ + if (!PTR_ERR(key)) + request_key_link(key, dest_keyring); } - error: +error: + kleave(" = %p", key); return key; +nomem: + key = ERR_PTR(-ENOMEM); + goto error; + +interrupted: + key_user_put(user); + key = ERR_PTR(-EINTR); + goto error; + +} /* end request_key_and_link() */ + +/*****************************************************************************/ +/* + * 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 + */ +struct key *request_key(struct key_type *type, + const char *description, + const char *callout_info) +{ + return request_key_and_link(type, description, callout_info, NULL); + } /* end request_key() */ EXPORT_SYMBOL(request_key); @@ -339,7 +453,8 @@ int key_validate(struct key *key) if (key) { /* check it's still accessible */ ret = -EKEYREVOKED; - if (key->flags & (KEY_FLAG_REVOKED | KEY_FLAG_DEAD)) + if (test_bit(KEY_FLAG_REVOKED, &key->flags) || + test_bit(KEY_FLAG_DEAD, &key->flags)) goto error; /* check it hasn't expired */ diff --git a/security/keys/request_key_auth.c b/security/keys/request_key_auth.c new file mode 100644 index 0000000..f222646 --- /dev/null +++ b/security/keys/request_key_auth.c @@ -0,0 +1,180 @@ +/* request_key_auth.c: request key authorisation controlling key def + * + * Copyright (C) 2005 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 License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include <linux/module.h> +#include <linux/sched.h> +#include <linux/err.h> +#include <linux/seq_file.h> +#include "internal.h" + +static int request_key_auth_instantiate(struct key *, const void *, size_t); +static void request_key_auth_describe(const struct key *, struct seq_file *); +static void request_key_auth_destroy(struct key *); + +/* + * the request-key authorisation key type definition + */ +struct key_type key_type_request_key_auth = { + .name = ".request_key_auth", + .def_datalen = sizeof(struct request_key_auth), + .instantiate = request_key_auth_instantiate, + .describe = request_key_auth_describe, + .destroy = request_key_auth_destroy, +}; + +/*****************************************************************************/ +/* + * instantiate a request-key authorisation record + */ +static int request_key_auth_instantiate(struct key *key, + const void *data, + size_t datalen) +{ + struct request_key_auth *rka, *irka; + struct key *instkey; + int ret; + + ret = -ENOMEM; + rka = kmalloc(sizeof(*rka), GFP_KERNEL); + if (rka) { + /* see if the calling process is already servicing the key + * request of another process */ + instkey = key_get_instantiation_authkey(0); + if (!IS_ERR(instkey)) { + /* it is - use that instantiation context here too */ + irka = instkey->payload.data; + rka->context = irka->context; + rka->pid = irka->pid; + key_put(instkey); + } + else { + /* it isn't - use this process as the context */ + rka->context = current; + rka->pid = current->pid; + } + + rka->target_key = key_get((struct key *) data); + key->payload.data = rka; + ret = 0; + } + + return ret; + +} /* end request_key_auth_instantiate() */ + +/*****************************************************************************/ +/* + * + */ +static void request_key_auth_describe(const struct key *key, + struct seq_file *m) +{ + struct request_key_auth *rka = key->payload.data; + + seq_puts(m, "key:"); + seq_puts(m, key->description); + seq_printf(m, " pid:%d", rka->pid); + +} /* end request_key_auth_describe() */ + +/*****************************************************************************/ +/* + * destroy an instantiation authorisation token key + */ +static void request_key_auth_destroy(struct key *key) +{ + struct request_key_auth *rka = key->payload.data; + + kenter("{%d}", key->serial); + + key_put(rka->target_key); + +} /* end request_key_auth_destroy() */ + +/*****************************************************************************/ +/* + * 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() */ + +/*****************************************************************************/ +/* + * get the authorisation key for instantiation of a specific key if attached to + * the current process's keyrings + * - this key is inserted into a keyring and that is set as /sbin/request-key's + * session keyring + * - a target_id of zero specifies any valid token + */ +struct key *key_get_instantiation_authkey(key_serial_t target_id) +{ + struct task_struct *tsk = current; + struct key *instkey; + + /* we must have our own personal session keyring */ + if (!tsk->signal->session_keyring) + return ERR_PTR(-EACCES); + + /* and it must contain a suitable request authorisation key + * - lock RCU against session keyring changing + */ + rcu_read_lock(); + + instkey = keyring_search_instkey( + rcu_dereference(tsk->signal->session_keyring), target_id); + + rcu_read_unlock(); + return instkey; + +} /* end key_get_instantiation_authkey() */ diff --git a/security/keys/user_defined.c b/security/keys/user_defined.c index 8d65b3a..e446acb 100644 --- a/security/keys/user_defined.c +++ b/security/keys/user_defined.c @@ -42,12 +42,21 @@ struct key_type key_type_user = { .read = user_read, }; +struct user_key_payload { + struct rcu_head rcu; /* RCU destructor */ + unsigned short datalen; /* length of this data */ + char data[0]; /* actual data */ +}; + +EXPORT_SYMBOL_GPL(key_type_user); + /*****************************************************************************/ /* * instantiate a user defined key */ static int user_instantiate(struct key *key, const void *data, size_t datalen) { + struct user_key_payload *upayload; int ret; ret = -EINVAL; @@ -58,13 +67,15 @@ static int user_instantiate(struct key *key, const void *data, size_t datalen) if (ret < 0) goto error; - /* attach the data */ ret = -ENOMEM; - key->payload.data = kmalloc(datalen, GFP_KERNEL); - if (!key->payload.data) + upayload = kmalloc(sizeof(*upayload) + datalen, GFP_KERNEL); + if (!upayload) goto error; - memcpy(key->payload.data, data, datalen); + /* attach the data */ + upayload->datalen = datalen; + memcpy(upayload->data, data, datalen); + rcu_assign_pointer(key->payload.data, upayload); ret = 0; error: @@ -75,18 +86,25 @@ static int user_instantiate(struct key *key, const void *data, size_t datalen) /*****************************************************************************/ /* * duplicate a user defined key + * - both keys' semaphores are locked against further modification + * - the new key cannot yet be accessed */ static int user_duplicate(struct key *key, const struct key *source) { + struct user_key_payload *upayload, *spayload; int ret; /* just copy the payload */ ret = -ENOMEM; - key->payload.data = kmalloc(source->datalen, GFP_KERNEL); + upayload = kmalloc(sizeof(*upayload) + source->datalen, GFP_KERNEL); + if (upayload) { + spayload = rcu_dereference(source->payload.data); + BUG_ON(source->datalen != spayload->datalen); + + upayload->datalen = key->datalen = spayload->datalen; + memcpy(upayload->data, spayload->data, key->datalen); - if (key->payload.data) { - key->datalen = source->datalen; - memcpy(key->payload.data, source->payload.data, source->datalen); + key->payload.data = upayload; ret = 0; } @@ -96,40 +114,54 @@ static int user_duplicate(struct key *key, const struct key *source) /*****************************************************************************/ /* + * dispose of the old data from an updated user defined key + */ +static void user_update_rcu_disposal(struct rcu_head *rcu) +{ + struct user_key_payload *upayload; + + upayload = container_of(rcu, struct user_key_payload, rcu); + + kfree(upayload); + +} /* end user_update_rcu_disposal() */ + +/*****************************************************************************/ +/* * update a user defined key + * - the key's semaphore is write-locked */ static int user_update(struct key *key, const void *data, size_t datalen) { - void *new, *zap; + struct user_key_payload *upayload, *zap; int ret; ret = -EINVAL; if (datalen <= 0 || datalen > 32767 || !data) goto error; - /* copy the data */ + /* construct a replacement payload */ ret = -ENOMEM; - new = kmalloc(datalen, GFP_KERNEL); - if (!new) + upayload = kmalloc(sizeof(*upayload) + datalen, GFP_KERNEL); + if (!upayload) goto error; - memcpy(new, data, datalen); + upayload->datalen = datalen; + memcpy(upayload->data, data, datalen); /* check the quota and attach the new data */ - zap = new; - write_lock(&key->lock); + zap = upayload; ret = key_payload_reserve(key, datalen); if (ret == 0) { /* attach the new data, displacing the old */ zap = key->payload.data; - key->payload.data = new; + rcu_assign_pointer(key->payload.data, upayload); key->expiry = 0; } - write_unlock(&key->lock); - kfree(zap); + call_rcu(&zap->rcu, user_update_rcu_disposal); error: return ret; @@ -152,13 +184,15 @@ static int user_match(const struct key *key, const void *description) */ static void user_destroy(struct key *key) { - kfree(key->payload.data); + struct user_key_payload *upayload = key->payload.data; + + kfree(upayload); } /* end user_destroy() */ /*****************************************************************************/ /* - * describe the user + * describe the user key */ static void user_describe(const struct key *key, struct seq_file *m) { @@ -171,18 +205,23 @@ static void user_describe(const struct key *key, struct seq_file *m) /*****************************************************************************/ /* * read the key data + * - the key's semaphore is read-locked */ static long user_read(const struct key *key, char __user *buffer, size_t buflen) { - long ret = key->datalen; + struct user_key_payload *upayload; + long ret; + + upayload = rcu_dereference(key->payload.data); + ret = upayload->datalen; /* we can return the data as is */ if (buffer && buflen > 0) { - if (buflen > key->datalen) - buflen = key->datalen; + if (buflen > upayload->datalen) + buflen = upayload->datalen; - if (copy_to_user(buffer, key->payload.data, buflen) != 0) + if (copy_to_user(buffer, upayload->data, buflen) != 0) ret = -EFAULT; } diff --git a/security/seclvl.c b/security/seclvl.c index 8a0ab0d..c8e87b2 100644 --- a/security/seclvl.c +++ b/security/seclvl.c @@ -155,7 +155,7 @@ seclvl_attr_store(struct kobject *kobj, struct seclvl_obj *obj = container_of(kobj, struct seclvl_obj, kobj); struct seclvl_attribute *attribute = container_of(attr, struct seclvl_attribute, attr); - return (attribute->store ? attribute->store(obj, buf, len) : 0); + return attribute->store ? attribute->store(obj, buf, len) : -EIO; } static ssize_t @@ -164,7 +164,7 @@ seclvl_attr_show(struct kobject *kobj, struct attribute *attr, char *buf) struct seclvl_obj *obj = container_of(kobj, struct seclvl_obj, kobj); struct seclvl_attribute *attribute = container_of(attr, struct seclvl_attribute, attr); - return (attribute->show ? attribute->show(obj, buf) : 0); + return attribute->show ? attribute->show(obj, buf) : -EIO; } /** diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index b5220a2..5e755a3 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -68,6 +68,7 @@ #include <linux/personality.h> #include <linux/sysctl.h> #include <linux/audit.h> +#include <linux/string.h> #include "avc.h" #include "objsec.h" @@ -1658,9 +1659,8 @@ static int selinux_bprm_secureexec (struct linux_binprm *bprm) static void selinux_bprm_free_security(struct linux_binprm *bprm) { - struct bprm_security_struct *bsec = bprm->security; + kfree(bprm->security); bprm->security = NULL; - kfree(bsec); } extern struct vfsmount *selinuxfs_mount; @@ -1944,7 +1944,8 @@ static int selinux_sb_copy_data(struct file_system_type *type, void *orig, void } } while (*in_end++); - copy_page(in_save, nosec_save); + strcpy(in_save, nosec_save); + free_page((unsigned long)nosec_save); out: return rc; } @@ -2476,6 +2477,17 @@ static int selinux_file_mprotect(struct vm_area_struct *vma, prot = reqprot; #ifndef CONFIG_PPC32 + if ((prot & PROT_EXEC) && !(vma->vm_flags & VM_EXECUTABLE) && + (vma->vm_start >= vma->vm_mm->start_brk && + vma->vm_end <= vma->vm_mm->brk)) { + /* + * We are making an executable mapping in the brk region. + * This has an additional execheap check. + */ + rc = task_has_perm(current, current, PROCESS__EXECHEAP); + if (rc) + return rc; + } if (vma->vm_file != NULL && vma->anon_vma != NULL && (prot & PROT_EXEC)) { /* * We are making executable a file mapping that has @@ -2487,6 +2499,16 @@ static int selinux_file_mprotect(struct vm_area_struct *vma, if (rc) return rc; } + if (!vma->vm_file && (prot & PROT_EXEC) && + vma->vm_start <= vma->vm_mm->start_stack && + vma->vm_end >= vma->vm_mm->start_stack) { + /* Attempt to make the process stack executable. + * This has an additional execstack check. + */ + rc = task_has_perm(current, current, PROCESS__EXECSTACK); + if (rc) + return rc; + } #endif return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED); diff --git a/security/selinux/include/av_perm_to_string.h b/security/selinux/include/av_perm_to_string.h index 8928bb4d..1deb59e 100644 --- a/security/selinux/include/av_perm_to_string.h +++ b/security/selinux/include/av_perm_to_string.h @@ -70,6 +70,8 @@ S_(SECCLASS_PROCESS, PROCESS__DYNTRANSITION, "dyntransition") S_(SECCLASS_PROCESS, PROCESS__SETCURRENT, "setcurrent") S_(SECCLASS_PROCESS, PROCESS__EXECMEM, "execmem") + S_(SECCLASS_PROCESS, PROCESS__EXECSTACK, "execstack") + S_(SECCLASS_PROCESS, PROCESS__EXECHEAP, "execheap") S_(SECCLASS_MSGQ, MSGQ__ENQUEUE, "enqueue") S_(SECCLASS_MSG, MSG__SEND, "send") S_(SECCLASS_MSG, MSG__RECEIVE, "receive") diff --git a/security/selinux/include/av_permissions.h b/security/selinux/include/av_permissions.h index bdfce4c..a78b5d5 100644 --- a/security/selinux/include/av_permissions.h +++ b/security/selinux/include/av_permissions.h @@ -465,6 +465,8 @@ #define PROCESS__DYNTRANSITION 0x00800000UL #define PROCESS__SETCURRENT 0x01000000UL #define PROCESS__EXECMEM 0x02000000UL +#define PROCESS__EXECSTACK 0x04000000UL +#define PROCESS__EXECHEAP 0x08000000UL #define IPC__CREATE 0x00000001UL #define IPC__DESTROY 0x00000002UL diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c index 0722156..8eb140d 100644 --- a/security/selinux/selinuxfs.c +++ b/security/selinux/selinuxfs.c @@ -951,8 +951,7 @@ static int sel_make_bools(void) u32 sid; /* remove any existing files */ - if (bool_pending_values) - kfree(bool_pending_values); + kfree(bool_pending_values); sel_remove_bools(dir); @@ -997,10 +996,8 @@ static int sel_make_bools(void) out: free_page((unsigned long)page); if (names) { - for (i = 0; i < num; i++) { - if (names[i]) - kfree(names[i]); - } + for (i = 0; i < num; i++) + kfree(names[i]); kfree(names); } return ret; diff --git a/security/selinux/ss/conditional.c b/security/selinux/ss/conditional.c index b534411..e2057f5 100644 --- a/security/selinux/ss/conditional.c +++ b/security/selinux/ss/conditional.c @@ -166,16 +166,14 @@ static void cond_list_destroy(struct cond_node *list) void cond_policydb_destroy(struct policydb *p) { - if (p->bool_val_to_struct != NULL) - kfree(p->bool_val_to_struct); + kfree(p->bool_val_to_struct); avtab_destroy(&p->te_cond_avtab); cond_list_destroy(p->cond_list); } int cond_init_bool_indexes(struct policydb *p) { - if (p->bool_val_to_struct) - kfree(p->bool_val_to_struct); + kfree(p->bool_val_to_struct); p->bool_val_to_struct = (struct cond_bool_datum**) kmalloc(p->p_bools.nprim * sizeof(struct cond_bool_datum*), GFP_KERNEL); if (!p->bool_val_to_struct) @@ -185,8 +183,7 @@ int cond_init_bool_indexes(struct policydb *p) int cond_destroy_bool(void *key, void *datum, void *p) { - if (key) - kfree(key); + kfree(key); kfree(datum); return 0; } diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c index 14190ef..785c33c 100644 --- a/security/selinux/ss/policydb.c +++ b/security/selinux/ss/policydb.c @@ -590,17 +590,12 @@ void policydb_destroy(struct policydb *p) hashtab_destroy(p->symtab[i].table); } - for (i = 0; i < SYM_NUM; i++) { - if (p->sym_val_to_name[i]) - kfree(p->sym_val_to_name[i]); - } + for (i = 0; i < SYM_NUM; i++) + kfree(p->sym_val_to_name[i]); - if (p->class_val_to_struct) - kfree(p->class_val_to_struct); - if (p->role_val_to_struct) - kfree(p->role_val_to_struct); - if (p->user_val_to_struct) - kfree(p->user_val_to_struct); + kfree(p->class_val_to_struct); + kfree(p->role_val_to_struct); + kfree(p->user_val_to_struct); avtab_destroy(&p->te_avtab); diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index 2947cf8..bfa5a7d 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -1705,11 +1705,9 @@ out: err: if (*names) { for (i = 0; i < *len; i++) - if ((*names)[i]) - kfree((*names)[i]); + kfree((*names)[i]); } - if (*values) - kfree(*values); + kfree(*values); goto out; } |