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authorLinus Torvalds2015-11-05 15:32:38 -0800
committerLinus Torvalds2015-11-05 15:32:38 -0800
commit1873499e13648a2dd01a394ed3217c9290921b3d (patch)
tree3a662aadb3c02bbce2e9231a90da6e98b54d33d4 /Documentation/security
parent3460b01b12aaf0011cb30f6f502edd05752f70eb (diff)
parentba94c3ff20c9c179f2a80f0e4c71e1571ebbf5c7 (diff)
Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem update from James Morris: "This is mostly maintenance updates across the subsystem, with a notable update for TPM 2.0, and addition of Jarkko Sakkinen as a maintainer of that" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (40 commits) apparmor: clarify CRYPTO dependency selinux: Use a kmem_cache for allocation struct file_security_struct selinux: ioctl_has_perm should be static selinux: use sprintf return value selinux: use kstrdup() in security_get_bools() selinux: use kmemdup in security_sid_to_context_core() selinux: remove pointless cast in selinux_inode_setsecurity() selinux: introduce security_context_str_to_sid selinux: do not check open perm on ftruncate call selinux: change CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE default KEYS: Merge the type-specific data with the payload data KEYS: Provide a script to extract a module signature KEYS: Provide a script to extract the sys cert list from a vmlinux file keys: Be more consistent in selection of union members used certs: add .gitignore to stop git nagging about x509_certificate_list KEYS: use kvfree() in add_key Smack: limited capability for changing process label TPM: remove unnecessary little endian conversion vTPM: support little endian guests char: Drop owner assignment from i2c_driver ...
Diffstat (limited to 'Documentation/security')
-rw-r--r--Documentation/security/Smack.txt10
-rw-r--r--Documentation/security/keys.txt41
2 files changed, 35 insertions, 16 deletions
diff --git a/Documentation/security/Smack.txt b/Documentation/security/Smack.txt
index 5e6d07fbed07..945cc633d883 100644
--- a/Documentation/security/Smack.txt
+++ b/Documentation/security/Smack.txt
@@ -255,6 +255,16 @@ unconfined
the access permitted if it wouldn't be otherwise. Note that this
is dangerous and can ruin the proper labeling of your system.
It should never be used in production.
+relabel-self
+ This interface contains a list of labels to which the process can
+ transition to, by writing to /proc/self/attr/current.
+ Normally a process can change its own label to any legal value, but only
+ if it has CAP_MAC_ADMIN. This interface allows a process without
+ CAP_MAC_ADMIN to relabel itself to one of labels from predefined list.
+ A process without CAP_MAC_ADMIN can change its label only once. When it
+ does, this list will be cleared.
+ The values are set by writing the desired labels, separated
+ by spaces, to the file or cleared by writing "-" to the file.
If you are using the smackload utility
you can add access rules in /etc/smack/accesses. They take the form:
diff --git a/Documentation/security/keys.txt b/Documentation/security/keys.txt
index c9e7f4f223a5..8c183873b2b7 100644
--- a/Documentation/security/keys.txt
+++ b/Documentation/security/keys.txt
@@ -1049,12 +1049,12 @@ search a specific keyring, so using keyrings in this way is of limited utility.
NOTES ON ACCESSING PAYLOAD CONTENTS
===================================
-The simplest payload is just a number in key->payload.value. In this case,
-there's no need to indulge in RCU or locking when accessing the payload.
+The simplest payload is just data stored in key->payload directly. In this
+case, there's no need to indulge in RCU or locking when accessing the payload.
-More complex payload contents must be allocated and a pointer to them set in
-key->payload.data. One of the following ways must be selected to access the
-data:
+More complex payload contents must be allocated and pointers to them set in the
+key->payload.data[] array. One of the following ways must be selected to
+access the data:
(1) Unmodifiable key type.
@@ -1092,6 +1092,13 @@ data:
the payload. key->datalen cannot be relied upon to be consistent with the
payload just dereferenced if the key's semaphore is not held.
+ Note that key->payload.data[0] has a shadow that is marked for __rcu
+ usage. This is called key->payload.rcu_data0. The following accessors
+ wrap the RCU calls to this element:
+
+ rcu_assign_keypointer(struct key *key, void *data);
+ void *rcu_dereference_key(struct key *key);
+
===================
DEFINING A KEY TYPE
@@ -1143,8 +1150,7 @@ The structure has a number of fields, some of which are mandatory:
struct key_preparsed_payload {
char *description;
- void *type_data[2];
- void *payload;
+ union key_payload payload;
const void *data;
size_t datalen;
size_t quotalen;
@@ -1160,10 +1166,9 @@ The structure has a number of fields, some of which are mandatory:
attached as a string to the description field. This will be used for the
key description if the caller of add_key() passes NULL or "".
- The method can attach anything it likes to type_data[] and payload. These
- are merely passed along to the instantiate() or update() operations. If
- set, the expiry time will be applied to the key if it is instantiated from
- this data.
+ The method can attach anything it likes to payload. This is merely passed
+ along to the instantiate() or update() operations. If set, the expiry
+ time will be applied to the key if it is instantiated from this data.
The method should return 0 if successful or a negative error code
otherwise.
@@ -1172,11 +1177,10 @@ The structure has a number of fields, some of which are mandatory:
(*) void (*free_preparse)(struct key_preparsed_payload *prep);
This method is only required if the preparse() method is provided,
- otherwise it is unused. It cleans up anything attached to the
- description, type_data and payload fields of the key_preparsed_payload
- struct as filled in by the preparse() method. It will always be called
- after preparse() returns successfully, even if instantiate() or update()
- succeed.
+ otherwise it is unused. It cleans up anything attached to the description
+ and payload fields of the key_preparsed_payload struct as filled in by the
+ preparse() method. It will always be called after preparse() returns
+ successfully, even if instantiate() or update() succeed.
(*) int (*instantiate)(struct key *key, struct key_preparsed_payload *prep);
@@ -1197,6 +1201,11 @@ The structure has a number of fields, some of which are mandatory:
It is safe to sleep in this method.
+ generic_key_instantiate() is provided to simply copy the data from
+ prep->payload.data[] to key->payload.data[], with RCU-safe assignment on
+ the first element. It will then clear prep->payload.data[] so that the
+ free_preparse method doesn't release the data.
+
(*) int (*update)(struct key *key, const void *data, size_t datalen);