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-rw-r--r--Documentation/keys.txt22
-rw-r--r--include/linux/key-ui.h3
-rw-r--r--include/linux/key.h13
-rw-r--r--include/linux/security.h73
-rw-r--r--security/dummy.c23
-rw-r--r--security/keys/key.c56
-rw-r--r--security/keys/keyctl.c13
-rw-r--r--security/keys/keyring.c21
-rw-r--r--security/keys/permission.c7
-rw-r--r--security/keys/process_keys.c9
10 files changed, 191 insertions, 49 deletions
diff --git a/Documentation/keys.txt b/Documentation/keys.txt
index 4afe03a58c5..31154882000 100644
--- a/Documentation/keys.txt
+++ b/Documentation/keys.txt
@@ -196,7 +196,7 @@ KEY ACCESS PERMISSIONS
Keys have an owner user ID, a group access ID, and a permissions mask. The mask
has up to eight bits each for possessor, user, group and other access. Only
-five of each set of eight bits are defined. These permissions granted are:
+six of each set of eight bits are defined. These permissions granted are:
(*) View
@@ -224,6 +224,10 @@ five of each set of eight bits are defined. These permissions granted are:
keyring to a key, a process must have Write permission on the keyring and
Link permission on the key.
+ (*) Set Attribute
+
+ This permits a key's UID, GID and permissions mask to be changed.
+
For changing the ownership, group ID or permissions mask, being the owner of
the key or having the sysadmin capability is sufficient.
@@ -242,15 +246,15 @@ about the status of the key service:
this way:
SERIAL FLAGS USAGE EXPY PERM UID GID TYPE DESCRIPTION: SUMMARY
- 00000001 I----- 39 perm 1f1f0000 0 0 keyring _uid_ses.0: 1/4
- 00000002 I----- 2 perm 1f1f0000 0 0 keyring _uid.0: empty
- 00000007 I----- 1 perm 1f1f0000 0 0 keyring _pid.1: empty
- 0000018d I----- 1 perm 1f1f0000 0 0 keyring _pid.412: empty
- 000004d2 I--Q-- 1 perm 1f1f0000 32 -1 keyring _uid.32: 1/4
- 000004d3 I--Q-- 3 perm 1f1f0000 32 -1 keyring _uid_ses.32: empty
+ 00000001 I----- 39 perm 1f3f0000 0 0 keyring _uid_ses.0: 1/4
+ 00000002 I----- 2 perm 1f3f0000 0 0 keyring _uid.0: empty
+ 00000007 I----- 1 perm 1f3f0000 0 0 keyring _pid.1: empty
+ 0000018d I----- 1 perm 1f3f0000 0 0 keyring _pid.412: empty
+ 000004d2 I--Q-- 1 perm 1f3f0000 32 -1 keyring _uid.32: 1/4
+ 000004d3 I--Q-- 3 perm 1f3f0000 32 -1 keyring _uid_ses.32: empty
00000892 I--QU- 1 perm 1f000000 0 0 user metal:copper: 0
- 00000893 I--Q-N 1 35s 1f1f0000 0 0 user metal:silver: 0
- 00000894 I--Q-- 1 10h 001f0000 0 0 user metal:gold: 0
+ 00000893 I--Q-N 1 35s 1f3f0000 0 0 user metal:silver: 0
+ 00000894 I--Q-- 1 10h 003f0000 0 0 user metal:gold: 0
The flags are:
diff --git a/include/linux/key-ui.h b/include/linux/key-ui.h
index 7a2e332067c..e8b8a7a5c49 100644
--- a/include/linux/key-ui.h
+++ b/include/linux/key-ui.h
@@ -24,7 +24,8 @@ extern spinlock_t key_serial_lock;
#define KEY_WRITE 0x04 /* require permission to update / modify */
#define KEY_SEARCH 0x08 /* require permission to search (keyring) or find (key) */
#define KEY_LINK 0x10 /* require permission to link */
-#define KEY_ALL 0x1f /* all the above permissions */
+#define KEY_SETATTR 0x20 /* require permission to change attributes */
+#define KEY_ALL 0x3f /* all the above permissions */
/*
* the keyring payload contains a list of the keys to which the keyring is
diff --git a/include/linux/key.h b/include/linux/key.h
index f1efa016dbf..53513a3be53 100644
--- a/include/linux/key.h
+++ b/include/linux/key.h
@@ -40,28 +40,32 @@ struct key;
#define KEY_POS_WRITE 0x04000000 /* possessor can update key payload / add link to keyring */
#define KEY_POS_SEARCH 0x08000000 /* possessor can find a key in search / search a keyring */
#define KEY_POS_LINK 0x10000000 /* possessor can create a link to a key/keyring */
-#define KEY_POS_ALL 0x1f000000
+#define KEY_POS_SETATTR 0x20000000 /* possessor can set key attributes */
+#define KEY_POS_ALL 0x3f000000
#define KEY_USR_VIEW 0x00010000 /* user permissions... */
#define KEY_USR_READ 0x00020000
#define KEY_USR_WRITE 0x00040000
#define KEY_USR_SEARCH 0x00080000
#define KEY_USR_LINK 0x00100000
-#define KEY_USR_ALL 0x001f0000
+#define KEY_USR_SETATTR 0x00200000
+#define KEY_USR_ALL 0x003f0000
#define KEY_GRP_VIEW 0x00000100 /* group permissions... */
#define KEY_GRP_READ 0x00000200
#define KEY_GRP_WRITE 0x00000400
#define KEY_GRP_SEARCH 0x00000800
#define KEY_GRP_LINK 0x00001000
-#define KEY_GRP_ALL 0x00001f00
+#define KEY_GRP_SETATTR 0x00002000
+#define KEY_GRP_ALL 0x00003f00
#define KEY_OTH_VIEW 0x00000001 /* third party permissions... */
#define KEY_OTH_READ 0x00000002
#define KEY_OTH_WRITE 0x00000004
#define KEY_OTH_SEARCH 0x00000008
#define KEY_OTH_LINK 0x00000010
-#define KEY_OTH_ALL 0x0000001f
+#define KEY_OTH_SETATTR 0x00000020
+#define KEY_OTH_ALL 0x0000003f
struct seq_file;
struct user_struct;
@@ -119,6 +123,7 @@ struct key {
struct key_type *type; /* type of key */
struct rw_semaphore sem; /* change vs change sem */
struct key_user *user; /* owner of this key */
+ void *security; /* security data for this key */
time_t expiry; /* time at which key expires (or 0) */
uid_t uid;
gid_t gid;
diff --git a/include/linux/security.h b/include/linux/security.h
index 607ee209ea3..f7e0ae01871 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -30,6 +30,7 @@
#include <linux/shm.h>
#include <linux/msg.h>
#include <linux/sched.h>
+#include <linux/key.h>
struct ctl_table;
@@ -788,6 +789,27 @@ struct swap_info_struct;
* @sk_free_security:
* Deallocate security structure.
*
+ * Security hooks affecting all Key Management operations
+ *
+ * @key_alloc:
+ * Permit allocation of a key and assign security data. Note that key does
+ * not have a serial number assigned at this point.
+ * @key points to the key.
+ * Return 0 if permission is granted, -ve error otherwise.
+ * @key_free:
+ * Notification of destruction; free security data.
+ * @key points to the key.
+ * No return value.
+ * @key_permission:
+ * See whether a specific operational right is granted to a process on a
+ * key.
+ * @key_ref refers to the key (key pointer + possession attribute bit).
+ * @context points to the process to provide the context against which to
+ * evaluate the security data on the key.
+ * @perm describes the combination of permissions required of this key.
+ * Return 1 if permission granted, 0 if permission denied and -ve it the
+ * normal permissions model should be effected.
+ *
* Security hooks affecting all System V IPC operations.
*
* @ipc_permission:
@@ -1216,6 +1238,17 @@ struct security_operations {
int (*sk_alloc_security) (struct sock *sk, int family, gfp_t priority);
void (*sk_free_security) (struct sock *sk);
#endif /* CONFIG_SECURITY_NETWORK */
+
+ /* key management security hooks */
+#ifdef CONFIG_KEYS
+ int (*key_alloc)(struct key *key);
+ void (*key_free)(struct key *key);
+ int (*key_permission)(key_ref_t key_ref,
+ struct task_struct *context,
+ key_perm_t perm);
+
+#endif /* CONFIG_KEYS */
+
};
/* global variables */
@@ -2764,5 +2797,45 @@ static inline void security_sk_free(struct sock *sk)
}
#endif /* CONFIG_SECURITY_NETWORK */
+#ifdef CONFIG_KEYS
+#ifdef CONFIG_SECURITY
+static inline int security_key_alloc(struct key *key)
+{
+ return security_ops->key_alloc(key);
+}
+
+static inline void security_key_free(struct key *key)
+{
+ security_ops->key_free(key);
+}
+
+static inline int security_key_permission(key_ref_t key_ref,
+ struct task_struct *context,
+ key_perm_t perm)
+{
+ return security_ops->key_permission(key_ref, context, perm);
+}
+
+#else
+
+static inline int security_key_alloc(struct key *key)
+{
+ return 0;
+}
+
+static inline void security_key_free(struct key *key)
+{
+}
+
+static inline int security_key_permission(key_ref_t key_ref,
+ struct task_struct *context,
+ key_perm_t perm)
+{
+ return 0;
+}
+
+#endif
+#endif /* CONFIG_KEYS */
+
#endif /* ! __LINUX_SECURITY_H */
diff --git a/security/dummy.c b/security/dummy.c
index 2a0337a52d3..3ca5f2b828a 100644
--- a/security/dummy.c
+++ b/security/dummy.c
@@ -803,6 +803,23 @@ static int dummy_setprocattr(struct task_struct *p, char *name, void *value, siz
return -EINVAL;
}
+#ifdef CONFIG_KEYS
+static inline int dummy_key_alloc(struct key *key)
+{
+ return 0;
+}
+
+static inline void dummy_key_free(struct key *key)
+{
+}
+
+static inline int dummy_key_permission(key_ref_t key_ref,
+ struct task_struct *context,
+ key_perm_t perm)
+{
+ return 0;
+}
+#endif /* CONFIG_KEYS */
struct security_operations dummy_security_ops;
@@ -954,5 +971,11 @@ void security_fixup_ops (struct security_operations *ops)
set_to_dummy_if_null(ops, sk_alloc_security);
set_to_dummy_if_null(ops, sk_free_security);
#endif /* CONFIG_SECURITY_NETWORK */
+#ifdef CONFIG_KEYS
+ set_to_dummy_if_null(ops, key_alloc);
+ set_to_dummy_if_null(ops, key_free);
+ set_to_dummy_if_null(ops, key_permission);
+#endif /* CONFIG_KEYS */
+
}
diff --git a/security/keys/key.c b/security/keys/key.c
index 2182be9e930..ccde17aff61 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -1,6 +1,6 @@
/* key.c: basic authentication token and access key management
*
- * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
@@ -13,6 +13,7 @@
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/slab.h>
+#include <linux/security.h>
#include <linux/workqueue.h>
#include <linux/err.h>
#include "internal.h"
@@ -253,6 +254,7 @@ struct key *key_alloc(struct key_type *type, const char *desc,
struct key_user *user = NULL;
struct key *key;
size_t desclen, quotalen;
+ int ret;
key = ERR_PTR(-EINVAL);
if (!desc || !*desc)
@@ -305,6 +307,7 @@ struct key *key_alloc(struct key_type *type, const char *desc,
key->flags = 0;
key->expiry = 0;
key->payload.data = NULL;
+ key->security = NULL;
if (!not_in_quota)
key->flags |= 1 << KEY_FLAG_IN_QUOTA;
@@ -315,16 +318,34 @@ struct key *key_alloc(struct key_type *type, const char *desc,
key->magic = KEY_DEBUG_MAGIC;
#endif
+ /* let the security module know about the key */
+ ret = security_key_alloc(key);
+ if (ret < 0)
+ goto security_error;
+
/* publish the key by giving it a serial number */
atomic_inc(&user->nkeys);
key_alloc_serial(key);
- error:
+error:
return key;
- no_memory_3:
+security_error:
+ kfree(key->description);
+ kmem_cache_free(key_jar, key);
+ if (!not_in_quota) {
+ spin_lock(&user->lock);
+ user->qnkeys--;
+ user->qnbytes -= quotalen;
+ spin_unlock(&user->lock);
+ }
+ key_user_put(user);
+ key = ERR_PTR(ret);
+ goto error;
+
+no_memory_3:
kmem_cache_free(key_jar, key);
- no_memory_2:
+no_memory_2:
if (!not_in_quota) {
spin_lock(&user->lock);
user->qnkeys--;
@@ -332,11 +353,11 @@ struct key *key_alloc(struct key_type *type, const char *desc,
spin_unlock(&user->lock);
}
key_user_put(user);
- no_memory_1:
+no_memory_1:
key = ERR_PTR(-ENOMEM);
goto error;
- no_quota:
+no_quota:
spin_unlock(&user->lock);
key_user_put(user);
key = ERR_PTR(-EDQUOT);
@@ -556,6 +577,8 @@ static void key_cleanup(void *data)
key_check(key);
+ security_key_free(key);
+
/* deal with the user's key tracking and quota */
if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) {
spin_lock(&key->user->lock);
@@ -700,8 +723,8 @@ static inline key_ref_t __key_update(key_ref_t key_ref,
int ret;
/* need write permission on the key to update it */
- ret = -EACCES;
- if (!key_permission(key_ref, KEY_WRITE))
+ ret = key_permission(key_ref, KEY_WRITE);
+ if (ret < 0)
goto error;
ret = -EEXIST;
@@ -711,7 +734,6 @@ static inline key_ref_t __key_update(key_ref_t key_ref,
down_write(&key->sem);
ret = key->type->update(key, payload, plen);
-
if (ret == 0)
/* updating a negative key instantiates it */
clear_bit(KEY_FLAG_NEGATIVE, &key->flags);
@@ -768,9 +790,11 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
/* if we're going to allocate a new key, we're going to have
* to modify the keyring */
- key_ref = ERR_PTR(-EACCES);
- if (!key_permission(keyring_ref, KEY_WRITE))
+ ret = key_permission(keyring_ref, KEY_WRITE);
+ if (ret < 0) {
+ key_ref = ERR_PTR(ret);
goto error_3;
+ }
/* search for an existing key of the same type and description in the
* destination keyring
@@ -780,8 +804,8 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
goto found_matching_key;
/* decide on the permissions we want */
- perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK;
- perm |= KEY_USR_VIEW | KEY_USR_SEARCH | KEY_USR_LINK;
+ perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR;
+ perm |= KEY_USR_VIEW | KEY_USR_SEARCH | KEY_USR_LINK | KEY_USR_SETATTR;
if (ktype->read)
perm |= KEY_POS_READ | KEY_USR_READ;
@@ -840,16 +864,16 @@ int key_update(key_ref_t key_ref, const void *payload, size_t plen)
key_check(key);
/* the key must be writable */
- ret = -EACCES;
- if (!key_permission(key_ref, KEY_WRITE))
+ ret = key_permission(key_ref, KEY_WRITE);
+ if (ret < 0)
goto error;
/* attempt to update it if supported */
ret = -EOPNOTSUPP;
if (key->type->update) {
down_write(&key->sem);
- ret = key->type->update(key, payload, plen);
+ ret = key->type->update(key, payload, plen);
if (ret == 0)
/* updating a negative key instantiates it */
clear_bit(KEY_FLAG_NEGATIVE, &key->flags);
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 4c670ee6acf..b7a468fabdf 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -624,8 +624,8 @@ long keyctl_keyring_search(key_serial_t ringid,
/* link the resulting key to the destination keyring if we can */
if (dest_ref) {
- ret = -EACCES;
- if (!key_permission(key_ref, KEY_LINK))
+ ret = key_permission(key_ref, KEY_LINK);
+ if (ret < 0)
goto error6;
ret = key_link(key_ref_to_ptr(dest_ref), key_ref_to_ptr(key_ref));
@@ -676,8 +676,11 @@ long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen)
key = key_ref_to_ptr(key_ref);
/* see if we can read it directly */
- if (key_permission(key_ref, KEY_READ))
+ ret = key_permission(key_ref, KEY_READ);
+ if (ret == 0)
goto can_read_key;
+ if (ret != -EACCES)
+ goto error;
/* we can't; see if it's searchable from this process's keyrings
* - we automatically take account of the fact that it may be
@@ -726,7 +729,7 @@ long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid)
if (uid == (uid_t) -1 && gid == (gid_t) -1)
goto error;
- key_ref = lookup_user_key(NULL, id, 1, 1, 0);
+ key_ref = lookup_user_key(NULL, id, 1, 1, KEY_SETATTR);
if (IS_ERR(key_ref)) {
ret = PTR_ERR(key_ref);
goto error;
@@ -786,7 +789,7 @@ long keyctl_setperm_key(key_serial_t id, key_perm_t perm)
if (perm & ~(KEY_POS_ALL | KEY_USR_ALL | KEY_GRP_ALL | KEY_OTH_ALL))
goto error;
- key_ref = lookup_user_key(NULL, id, 1, 1, 0);
+ key_ref = lookup_user_key(NULL, id, 1, 1, KEY_SETATTR);
if (IS_ERR(key_ref)) {
ret = PTR_ERR(key_ref);
goto error;
diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index 0639396dd44..e1cc4dd7901 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -13,6 +13,7 @@
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/slab.h>
+#include <linux/security.h>
#include <linux/seq_file.h>
#include <linux/err.h>
#include <asm/uaccess.h>
@@ -309,7 +310,9 @@ struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid,
int ret;
keyring = key_alloc(&key_type_keyring, description,
- uid, gid, KEY_POS_ALL | KEY_USR_ALL, not_in_quota);
+ uid, gid,
+ (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL,
+ not_in_quota);
if (!IS_ERR(keyring)) {
ret = key_instantiate_and_link(keyring, NULL, 0, dest, NULL);
@@ -359,9 +362,11 @@ key_ref_t keyring_search_aux(key_ref_t keyring_ref,
key_check(keyring);
/* top keyring must have search permission to begin the search */
- key_ref = ERR_PTR(-EACCES);
- if (!key_task_permission(keyring_ref, context, KEY_SEARCH))
+ err = key_task_permission(keyring_ref, context, KEY_SEARCH);
+ if (err < 0) {
+ key_ref = ERR_PTR(err);
goto error;
+ }
key_ref = ERR_PTR(-ENOTDIR);
if (keyring->type != &key_type_keyring)
@@ -402,8 +407,8 @@ descend:
continue;
/* key must have search permissions */
- if (!key_task_permission(make_key_ref(key, possessed),
- context, KEY_SEARCH))
+ if (key_task_permission(make_key_ref(key, possessed),
+ context, KEY_SEARCH) < 0)
continue;
/* we set a different error code if we find a negative key */
@@ -430,7 +435,7 @@ ascend:
continue;
if (!key_task_permission(make_key_ref(key, possessed),
- context, KEY_SEARCH))
+ context, KEY_SEARCH) < 0)
continue;
/* stack the current position */
@@ -521,7 +526,7 @@ key_ref_t __keyring_search_one(key_ref_t keyring_ref,
(!key->type->match ||
key->type->match(key, description)) &&
key_permission(make_key_ref(key, possessed),
- perm) &&
+ perm) < 0 &&
!test_bit(KEY_FLAG_REVOKED, &key->flags)
)
goto found;
@@ -617,7 +622,7 @@ struct key *find_keyring_by_name(const char *name, key_serial_t bound)
continue;
if (!key_permission(make_key_ref(keyring, 0),
- KEY_SEARCH))
+ KEY_SEARCH) < 0)
continue;
/* found a potential candidate, but we still need to
diff --git a/security/keys/permission.c b/security/keys/permission.c
index 03db073ba45..e7f579c0eaf 100644
--- a/security/keys/permission.c
+++ b/security/keys/permission.c
@@ -10,6 +10,7 @@
*/
#include <linux/module.h>
+#include <linux/security.h>
#include "internal.h"
/*****************************************************************************/
@@ -63,7 +64,11 @@ use_these_perms:
kperm = kperm & perm & KEY_ALL;
- return kperm == perm;
+ if (kperm != perm)
+ return -EACCES;
+
+ /* let LSM be the final arbiter */
+ return security_key_permission(key_ref, context, perm);
} /* end key_task_permission() */
diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index d42d2158ce1..566b1cc0118 100644
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -39,7 +39,7 @@ struct key root_user_keyring = {
.type = &key_type_keyring,
.user = &root_key_user,
.sem = __RWSEM_INITIALIZER(root_user_keyring.sem),
- .perm = KEY_POS_ALL | KEY_USR_ALL,
+ .perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL,
.flags = 1 << KEY_FLAG_INSTANTIATED,
.description = "_uid.0",
#ifdef KEY_DEBUGGING
@@ -54,7 +54,7 @@ struct key root_session_keyring = {
.type = &key_type_keyring,
.user = &root_key_user,
.sem = __RWSEM_INITIALIZER(root_session_keyring.sem),
- .perm = KEY_POS_ALL | KEY_USR_ALL,
+ .perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL,
.flags = 1 << KEY_FLAG_INSTANTIATED,
.description = "_uid_ses.0",
#ifdef KEY_DEBUGGING
@@ -666,9 +666,8 @@ key_ref_t lookup_user_key(struct task_struct *context, key_serial_t id,
goto invalid_key;
/* check the permissions */
- ret = -EACCES;
-
- if (!key_task_permission(key_ref, context, perm))
+ ret = key_task_permission(key_ref, context, perm);
+ if (ret < 0)
goto invalid_key;
error:
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-25 18:24:53 +0000