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Subject[PATCH 1/4] KEYS: Replace uid/gid/perm permissions checking with an ACL
From
Date
Replace the uid/gid/perm permissions checking on a key with an ACL to allow
the SETATTR and SEARCH permissions to be split.

============
WHY DO THIS?
============

The problem is that SETATTR and SEARCH cover a slew of actions, not all of
which should be grouped together.

For SETATTR, this includes actions that are about controlling access to a
key:

(1) Changing a key's ownership.

(2) Changing a key's security information.

(3) Setting a keyring's restriction.

And actions that are about managing a key's lifetime:

(4) Setting an expiry time.

(5) Revoking a key.

and (proposed) managing a key as part of a cache:

(6) Invalidating a key.

Managing a key's lifetime doesn't really have anything to do with
controlling access to that key.

Expiry time is awkward since it's more about the lifetime of the content
and so, in some ways goes better with WRITE permission. It can, however,
be set unconditionally by a process with an appropriate authorisation token
for instantiating a key, and can also be set by the key type driver when a
key is instantiated, so lumping it with the access-controlling actions is
probably okay.

As for SEARCH permission, that currently covers:

(1) Finding keys in a keyring tree during a search.

(2) Permitting keyrings to be joined.

(3) Invalidation.

But these don't really belong together either, since these actions really
need to be controlled separately.

Finally, there are number of special cases to do with granting the
administrator special rights to invalidate or clear keys that I would like
to handle with the ACL rather than key flags and special checks.


===============
WHAT IS CHANGED
===============

The SETATTR permission is split to create two new permissions:

(1) SET_SECURITY - which allows the key's owner, group and ACL to be
changed and a restriction to be placed on a keyring.

(2) REVOKE - which allows a key to be revoked.

The SEARCH permission is split to create:

(1) SEARCH - which allows a keyring to be search and a key to be found.

(2) JOIN - which allows a keyring to be joined as a session keyring.

(3) INVAL - which allows a key to be invalidated.

The WRITE permission is also split to create:

(1) WRITE - which allows a key's content to be altered and links to be
added, removed and replaced in a keyring.

(2) CLEAR - which allows a keyring to be cleared completely. This is
split out to make it possible to give just this to an administrator.

(3) REVOKE - see above.


Keys acquire ACLs which consist of a series of ACEs, and all that apply are
unioned together. An ACE specifies a subject, such as:

(*) Possessor - permitted to anyone who 'possesses' a key
(*) Owner - permitted to the key owner
(*) Group - permitted to the key group
(*) Everyone - permitted to everyone

Note that 'Other' has been replaced with 'Everyone' on the assumption that
you wouldn't grant a permit to 'Other' that you wouldn't also grant to
everyone else.

Further subjects may be made available by later patches.

The ACE also specifies a permissions mask. The set of permissions is now:

VIEW Can view the key metadata
READ Can read the key content
WRITE Can update/modify the key content
SEARCH Can find the key by searching/requesting
LINK Can make a link to the key
SET_SECURITY Can change owner, ACL, expiry
INVAL Can invalidate
REVOKE Can revoke
JOIN Can join this keyring
CLEAR Can clear this keyring


The KEYCTL_SETPERM function is then deprecated.

The KEYCTL_SET_TIMEOUT function then is permitted if SET_SECURITY is set,
or if the caller has a valid instantiation auth token.

The KEYCTL_INVALIDATE function then requires INVAL.

The KEYCTL_REVOKE function then requires REVOKE.

The KEYCTL_JOIN_SESSION_KEYRING function then requires JOIN to join an
existing keyring.

The JOIN permission is enabled by default for session keyrings and manually
created keyrings only.


======================
BACKWARD COMPATIBILITY
======================

To maintain backward compatibility, KEYCTL_SETPERM will translate the
permissions mask it is given into a new ACL for a key - unless
KEYCTL_SET_ACL has been called on that key, in which case an error will be
returned.

It will convert possessor, owner, group and other permissions into separate
ACEs, if each portion of the mask is non-zero.

SETATTR permission turns on all of INVAL, REVOKE and SET_SECURITY. WRITE
permission turns on WRITE, REVOKE and, if a keyring, CLEAR. JOIN is turned
on if a keyring is being altered.

The KEYCTL_DESCRIBE function translates the ACL back into a permissions
mask to return depending on possessor, owner, group and everyone ACEs.

It will make the following mappings:

(1) INVAL, JOIN -> SEARCH

(2) SET_SECURITY -> SETATTR

(3) REVOKE -> WRITE if SETATTR isn't already set

(4) CLEAR -> WRITE

Note that the value subsequently returned by KEYCTL_DESCRIBE may not match
the value set with KEYCTL_SETATTR.


=======
TESTING
=======

This passes the keyutils testsuite for all but a couple of tests:

(1) tests/keyctl/dh_compute/badargs: The first wrong-key-type test now
returns EOPNOTSUPP rather than ENOKEY as READ permission isn't removed
if the type doesn't have ->read(). You still can't actually read the
key.

(2) tests/keyctl/permitting/valid: The view-other-permissions test doesn't
work as Other has been replaced with Everyone in the ACL.

Signed-off-by: David Howells <dhowells@redhat.com>
---

certs/blacklist.c | 25 ++-
certs/system_keyring.c | 30 ++--
fs/afs/security.c | 2
fs/cifs/cifs_spnego.c | 24 ++-
fs/cifs/cifsacl.c | 27 +++
fs/cifs/connect.c | 4
fs/fscache/object-list.c | 2
fs/nfs/nfs4idmap.c | 28 +++
include/linux/key.h | 105 ++++++------
include/uapi/linux/keyctl.h | 64 ++++++++
net/dns_resolver/dns_key.c | 12 +
net/dns_resolver/dns_query.c | 13 +-
net/rxrpc/key.c | 14 +-
security/keys/encrypted-keys/encrypted.c | 2
security/keys/encrypted-keys/masterkey_trusted.c | 2
security/keys/gc.c | 2
security/keys/internal.h | 13 +-
security/keys/key.c | 29 +--
security/keys/keyctl.c | 91 ++++++++---
security/keys/keyring.c | 29 ++-
security/keys/permission.c | 185 +++++++++++++++++-----
security/keys/persistent.c | 24 ++-
security/keys/proc.c | 28 ++-
security/keys/process_keys.c | 68 ++++++--
security/keys/request_key.c | 47 +++---
security/keys/request_key_auth.c | 13 +-
security/selinux/hooks.c | 16 ++
security/smack/smack_lsm.c | 3
28 files changed, 659 insertions(+), 243 deletions(-)

diff --git a/certs/blacklist.c b/certs/blacklist.c
index 3a507b9e2568..6a4ab0c588ad 100644
--- a/certs/blacklist.c
+++ b/certs/blacklist.c
@@ -23,6 +23,24 @@

static struct key *blacklist_keyring;

+static struct key_acl blacklist_key_acl = {
+ .usage = REFCOUNT_INIT(1),
+ .nr_ace = 2,
+ .aces = {
+ KEY_POSSESSOR_ACE(KEY_ACE_SEARCH | KEY_ACE_READ),
+ KEY_OWNER_ACE(KEY_ACE_VIEW | KEY_ACE_SEARCH),
+ }
+};
+
+static struct key_acl blacklist_keyring_acl = {
+ .usage = REFCOUNT_INIT(1),
+ .nr_ace = 2,
+ .aces = {
+ KEY_POSSESSOR_ACE(KEY_ACE_SEARCH | KEY_ACE_WRITE),
+ KEY_OWNER_ACE(KEY_ACE_VIEW | KEY_ACE_READ | KEY_ACE_SEARCH),
+ }
+};
+
/*
* The description must be a type prefix, a colon and then an even number of
* hex digits. The hash is kept in the description.
@@ -93,8 +111,7 @@ int mark_hash_blacklisted(const char *hash)
hash,
NULL,
0,
- ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
- KEY_USR_VIEW),
+ &blacklist_key_acl,
KEY_ALLOC_NOT_IN_QUOTA |
KEY_ALLOC_BUILT_IN);
if (IS_ERR(key)) {
@@ -153,9 +170,7 @@ static int __init blacklist_init(void)
keyring_alloc(".blacklist",
KUIDT_INIT(0), KGIDT_INIT(0),
current_cred(),
- (KEY_POS_ALL & ~KEY_POS_SETATTR) |
- KEY_USR_VIEW | KEY_USR_READ |
- KEY_USR_SEARCH,
+ &blacklist_keyring_acl,
KEY_ALLOC_NOT_IN_QUOTA |
KEY_FLAG_KEEP,
NULL, NULL);
diff --git a/certs/system_keyring.c b/certs/system_keyring.c
index 6251d1b27f0c..f009066d241c 100644
--- a/certs/system_keyring.c
+++ b/certs/system_keyring.c
@@ -27,6 +27,24 @@ static struct key *secondary_trusted_keys;
extern __initconst const u8 system_certificate_list[];
extern __initconst const unsigned long system_certificate_list_size;

+static struct key_acl trusted_key_acl = {
+ .usage = REFCOUNT_INIT(1),
+ .nr_ace = 2,
+ .aces = {
+ KEY_POSSESSOR_ACE(KEY_ACE_SEARCH | KEY_ACE_READ),
+ KEY_OWNER_ACE(KEY_ACE_VIEW | KEY_ACE_READ | KEY_ACE_SEARCH),
+ }
+};
+
+static struct key_acl trusted_keyring_acl = {
+ .usage = REFCOUNT_INIT(1),
+ .nr_ace = 2,
+ .aces = {
+ KEY_POSSESSOR_ACE(KEY_ACE_SEARCH | KEY_ACE_WRITE),
+ KEY_OWNER_ACE(KEY_ACE_VIEW | KEY_ACE_READ | KEY_ACE_WRITE | KEY_ACE_SEARCH),
+ }
+};
+
/**
* restrict_link_to_builtin_trusted - Restrict keyring addition by built in CA
*
@@ -99,9 +117,7 @@ static __init int system_trusted_keyring_init(void)
builtin_trusted_keys =
keyring_alloc(".builtin_trusted_keys",
KUIDT_INIT(0), KGIDT_INIT(0), current_cred(),
- ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
- KEY_USR_VIEW | KEY_USR_READ | KEY_USR_SEARCH),
- KEY_ALLOC_NOT_IN_QUOTA,
+ &trusted_key_acl, KEY_ALLOC_NOT_IN_QUOTA,
NULL, NULL);
if (IS_ERR(builtin_trusted_keys))
panic("Can't allocate builtin trusted keyring\n");
@@ -110,10 +126,7 @@ static __init int system_trusted_keyring_init(void)
secondary_trusted_keys =
keyring_alloc(".secondary_trusted_keys",
KUIDT_INIT(0), KGIDT_INIT(0), current_cred(),
- ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
- KEY_USR_VIEW | KEY_USR_READ | KEY_USR_SEARCH |
- KEY_USR_WRITE),
- KEY_ALLOC_NOT_IN_QUOTA,
+ &trusted_keyring_acl, KEY_ALLOC_NOT_IN_QUOTA,
get_builtin_and_secondary_restriction(),
NULL);
if (IS_ERR(secondary_trusted_keys))
@@ -163,8 +176,7 @@ static __init int load_system_certificate_list(void)
NULL,
p,
plen,
- ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
- KEY_USR_VIEW | KEY_USR_READ),
+ &trusted_key_acl,
KEY_ALLOC_NOT_IN_QUOTA |
KEY_ALLOC_BUILT_IN |
KEY_ALLOC_BYPASS_RESTRICTION);
diff --git a/fs/afs/security.c b/fs/afs/security.c
index faca66227ecf..9131c2032d3f 100644
--- a/fs/afs/security.c
+++ b/fs/afs/security.c
@@ -28,7 +28,7 @@ struct key *afs_request_key(struct afs_cell *cell)

_debug("key %s", cell->anonymous_key->description);
key = request_key(&key_type_rxrpc, cell->anonymous_key->description,
- NULL);
+ NULL, NULL);
if (IS_ERR(key)) {
if (PTR_ERR(key) != -ENOKEY) {
_leave(" = %ld", PTR_ERR(key));
diff --git a/fs/cifs/cifs_spnego.c b/fs/cifs/cifs_spnego.c
index b611fc2e8984..557be8100e0c 100644
--- a/fs/cifs/cifs_spnego.c
+++ b/fs/cifs/cifs_spnego.c
@@ -32,6 +32,24 @@
#include "cifsproto.h"
static const struct cred *spnego_cred;

+static struct key_acl cifs_spnego_key_acl = {
+ .usage = REFCOUNT_INIT(1),
+ .nr_ace = 2,
+ .aces = {
+ KEY_POSSESSOR_ACE(KEY_ACE_VIEW | KEY_ACE_SEARCH | KEY_ACE_READ),
+ KEY_OWNER_ACE(KEY_ACE_VIEW),
+ }
+};
+
+static struct key_acl cifs_spnego_keyring_acl = {
+ .usage = REFCOUNT_INIT(1),
+ .nr_ace = 2,
+ .aces = {
+ KEY_POSSESSOR_ACE(KEY_ACE_SEARCH | KEY_ACE_WRITE),
+ KEY_OWNER_ACE(KEY_ACE_VIEW | KEY_ACE_READ),
+ }
+};
+
/* create a new cifs key */
static int
cifs_spnego_key_instantiate(struct key *key, struct key_preparsed_payload *prep)
@@ -168,7 +186,8 @@ cifs_get_spnego_key(struct cifs_ses *sesInfo)

cifs_dbg(FYI, "key description = %s\n", description);
saved_cred = override_creds(spnego_cred);
- spnego_key = request_key(&cifs_spnego_key_type, description, "");
+ spnego_key = request_key(&cifs_spnego_key_type, description, "",
+ &cifs_spnego_key_acl);
revert_creds(saved_cred);

#ifdef CONFIG_CIFS_DEBUG2
@@ -205,8 +224,7 @@ init_cifs_spnego(void)

keyring = keyring_alloc(".cifs_spnego",
GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred,
- (KEY_POS_ALL & ~KEY_POS_SETATTR) |
- KEY_USR_VIEW | KEY_USR_READ,
+ &cifs_spnego_keyring_acl,
KEY_ALLOC_NOT_IN_QUOTA, NULL, NULL);
if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c
index b98436f5c7c7..ee0b6ed07bf3 100644
--- a/fs/cifs/cifsacl.c
+++ b/fs/cifs/cifsacl.c
@@ -33,6 +33,24 @@
#include "cifsproto.h"
#include "cifs_debug.h"

+static struct key_acl cifs_idmap_key_acl = {
+ .usage = REFCOUNT_INIT(1),
+ .nr_ace = 2,
+ .aces = {
+ KEY_POSSESSOR_ACE(KEY_ACE_VIEW | KEY_ACE_SEARCH | KEY_ACE_READ),
+ KEY_OWNER_ACE(KEY_ACE_VIEW),
+ }
+};
+
+static struct key_acl cifs_idmap_keyring_acl = {
+ .usage = REFCOUNT_INIT(1),
+ .nr_ace = 2,
+ .aces = {
+ KEY_POSSESSOR_ACE(KEY_ACE_SEARCH | KEY_ACE_WRITE),
+ KEY_OWNER_ACE(KEY_ACE_VIEW | KEY_ACE_READ),
+ }
+};
+
/* security id for everyone/world system group */
static const struct cifs_sid sid_everyone = {
1, 1, {0, 0, 0, 0, 0, 1}, {0} };
@@ -298,7 +316,8 @@ id_to_sid(unsigned int cid, uint sidtype, struct cifs_sid *ssid)

rc = 0;
saved_cred = override_creds(root_cred);
- sidkey = request_key(&cifs_idmap_key_type, desc, "");
+ sidkey = request_key(&cifs_idmap_key_type, desc, "",
+ &cifs_idmap_key_acl);
if (IS_ERR(sidkey)) {
rc = -EINVAL;
cifs_dbg(FYI, "%s: Can't map %cid %u to a SID\n",
@@ -403,7 +422,8 @@ sid_to_id(struct cifs_sb_info *cifs_sb, struct cifs_sid *psid,
return -ENOMEM;

saved_cred = override_creds(root_cred);
- sidkey = request_key(&cifs_idmap_key_type, sidstr, "");
+ sidkey = request_key(&cifs_idmap_key_type, sidstr, "",
+ &cifs_idmap_key_acl);
if (IS_ERR(sidkey)) {
rc = -EINVAL;
cifs_dbg(FYI, "%s: Can't map SID %s to a %cid\n",
@@ -481,8 +501,7 @@ init_cifs_idmap(void)

keyring = keyring_alloc(".cifs_idmap",
GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred,
- (KEY_POS_ALL & ~KEY_POS_SETATTR) |
- KEY_USR_VIEW | KEY_USR_READ,
+ &cifs_idmap_keyring_acl,
KEY_ALLOC_NOT_IN_QUOTA, NULL, NULL);
if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 0bfc2280436d..20e7b83c414d 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -2479,7 +2479,7 @@ cifs_set_cifscreds(struct smb_vol *vol, struct cifs_ses *ses)
}

cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
- key = request_key(&key_type_logon, desc, "");
+ key = request_key(&key_type_logon, desc, "", NULL);
if (IS_ERR(key)) {
if (!ses->domainName) {
cifs_dbg(FYI, "domainName is NULL\n");
@@ -2490,7 +2490,7 @@ cifs_set_cifscreds(struct smb_vol *vol, struct cifs_ses *ses)
/* didn't work, try to find a domain key */
sprintf(desc, "cifs:d:%s", ses->domainName);
cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
- key = request_key(&key_type_logon, desc, "");
+ key = request_key(&key_type_logon, desc, "", NULL);
if (IS_ERR(key)) {
rc = PTR_ERR(key);
goto out_err;
diff --git a/fs/fscache/object-list.c b/fs/fscache/object-list.c
index b5ab06fabc60..c8b259ca1b92 100644
--- a/fs/fscache/object-list.c
+++ b/fs/fscache/object-list.c
@@ -323,7 +323,7 @@ static void fscache_objlist_config(struct fscache_objlist_data *data)
const char *buf;
int len;

- key = request_key(&key_type_user, "fscache:objlist", NULL);
+ key = request_key(&key_type_user, "fscache:objlist", NULL, NULL);
if (IS_ERR(key))
goto no_config;

diff --git a/fs/nfs/nfs4idmap.c b/fs/nfs/nfs4idmap.c
index dd5d27da8c0c..13de8d91cbf6 100644
--- a/fs/nfs/nfs4idmap.c
+++ b/fs/nfs/nfs4idmap.c
@@ -70,6 +70,24 @@ struct idmap {
struct mutex idmap_mutex;
};

+static struct key_acl nfs_idmap_key_acl = {
+ .usage = REFCOUNT_INIT(1),
+ .nr_ace = 2,
+ .aces = {
+ KEY_POSSESSOR_ACE(KEY_ACE_VIEW | KEY_ACE_SEARCH | KEY_ACE_READ),
+ KEY_OWNER_ACE(KEY_ACE_VIEW),
+ }
+};
+
+static struct key_acl nfs_idmap_keyring_acl = {
+ .usage = REFCOUNT_INIT(1),
+ .nr_ace = 2,
+ .aces = {
+ KEY_POSSESSOR_ACE(KEY_ACE_SEARCH | KEY_ACE_WRITE),
+ KEY_OWNER_ACE(KEY_ACE_VIEW | KEY_ACE_READ),
+ }
+};
+
/**
* nfs_fattr_init_names - initialise the nfs_fattr owner_name/group_name fields
* @fattr: fully initialised struct nfs_fattr
@@ -199,8 +217,7 @@ int nfs_idmap_init(void)

keyring = keyring_alloc(".id_resolver",
GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred,
- (KEY_POS_ALL & ~KEY_POS_SETATTR) |
- KEY_USR_VIEW | KEY_USR_READ,
+ &nfs_idmap_keyring_acl,
KEY_ALLOC_NOT_IN_QUOTA, NULL, NULL);
if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
@@ -277,11 +294,12 @@ static struct key *nfs_idmap_request_key(const char *name, size_t namelen,
if (ret <= 0)
return ERR_PTR(ret);

- rkey = request_key(&key_type_id_resolver, desc, "");
+ rkey = request_key(&key_type_id_resolver, desc, "", &nfs_idmap_key_acl);
if (IS_ERR(rkey)) {
mutex_lock(&idmap->idmap_mutex);
rkey = request_key_with_auxdata(&key_type_id_resolver_legacy,
- desc, "", 0, idmap);
+ desc, "", 0, idmap,
+ &nfs_idmap_key_acl);
mutex_unlock(&idmap->idmap_mutex);
}
if (!IS_ERR(rkey))
@@ -310,8 +328,6 @@ static ssize_t nfs_idmap_get_key(const char *name, size_t namelen,
}

rcu_read_lock();
- rkey->perm |= KEY_USR_VIEW;
-
ret = key_validate(rkey);
if (ret < 0)
goto out_up;
diff --git a/include/linux/key.h b/include/linux/key.h
index e315e16b6ff8..11a667c760a9 100644
--- a/include/linux/key.h
+++ b/include/linux/key.h
@@ -31,48 +31,13 @@
/* key handle serial number */
typedef int32_t key_serial_t;

-/* key handle permissions mask */
-typedef uint32_t key_perm_t;
-
struct key;

#ifdef CONFIG_KEYS

-#undef KEY_DEBUGGING
+#include <linux/keyctl.h>

-#define KEY_POS_VIEW 0x01000000 /* possessor can view a key's attributes */
-#define KEY_POS_READ 0x02000000 /* possessor can read key payload / view keyring */
-#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_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_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_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_SETATTR 0x00000020
-#define KEY_OTH_ALL 0x0000003f
-
-#define KEY_PERM_UNDEF 0xffffffff
+#undef KEY_DEBUGGING

struct seq_file;
struct user_struct;
@@ -95,6 +60,32 @@ union key_payload {
void *data[4];
};

+struct kernel_key_ace {
+ unsigned int mask;
+ union {
+ kuid_t uid;
+ kgid_t gid;
+ unsigned int subject_id;
+ };
+};
+
+struct key_acl {
+ refcount_t usage;
+ unsigned int nr_ace;
+ struct rcu_head rcu;
+ struct kernel_key_ace aces[];
+};
+
+#define KEY_POSSESSOR_ACE(perms) { \
+ .mask = KEY_ACE_SUBJECT_ID | (perms), \
+ .subject_id = KEY_ACE_POSSESSOR \
+ }
+
+#define KEY_OWNER_ACE(perms) { \
+ .mask = KEY_ACE_SUBJECT_ID | (perms), \
+ .subject_id = KEY_ACE_OWNER \
+ }
+
/*****************************************************************************/
/*
* key reference with possession attribute handling
@@ -156,6 +147,7 @@ struct key {
struct rw_semaphore sem; /* change vs change sem */
struct key_user *user; /* owner of this key */
void *security; /* security data for this key */
+ struct key_acl __rcu *acl;
union {
time_t expiry; /* time at which key expires (or 0) */
time_t revoked_at; /* time at which key was revoked */
@@ -163,7 +155,6 @@ struct key {
time_t last_used_at; /* last time used for LRU keyring discard */
kuid_t uid;
kgid_t gid;
- key_perm_t perm; /* access permissions */
unsigned short quotalen; /* length added to quota */
unsigned short datalen; /* payload data length
* - may not match RCU dereferenced payload
@@ -188,6 +179,7 @@ struct key {
#define KEY_FLAG_ROOT_CAN_INVAL 9 /* set if key can be invalidated by root without permission */
#define KEY_FLAG_KEEP 10 /* set if key should not be removed */
#define KEY_FLAG_UID_KEYRING 11 /* set if key is a user or user session keyring */
+#define KEY_FLAG_HAS_ACL 12 /* Set if KEYCTL_SETACL called on key */

/* the key type and key description string
* - the desc is used to match a key against search criteria
@@ -234,7 +226,7 @@ extern struct key *key_alloc(struct key_type *type,
const char *desc,
kuid_t uid, kgid_t gid,
const struct cred *cred,
- key_perm_t perm,
+ struct key_acl *acl,
unsigned long flags,
struct key_restriction *restrict_link);

@@ -268,24 +260,28 @@ static inline void key_ref_put(key_ref_t key_ref)

extern struct key *request_key(struct key_type *type,
const char *description,
- const char *callout_info);
+ const char *callout_info,
+ struct key_acl *acl);

extern struct key *request_key_with_auxdata(struct key_type *type,
const char *description,
const void *callout_info,
size_t callout_len,
- void *aux);
+ void *aux,
+ struct key_acl *acl);

extern struct key *request_key_async(struct key_type *type,
const char *description,
const void *callout_info,
- size_t callout_len);
+ size_t callout_len,
+ struct key_acl *acl);

extern struct key *request_key_async_with_auxdata(struct key_type *type,
const char *description,
const void *callout_info,
size_t callout_len,
- void *aux);
+ void *aux,
+ struct key_acl *acl);

extern int wait_for_key_construction(struct key *key, bool intr);

@@ -296,7 +292,7 @@ extern key_ref_t key_create_or_update(key_ref_t keyring,
const char *description,
const void *payload,
size_t plen,
- key_perm_t perm,
+ struct key_acl *acl,
unsigned long flags);

extern int key_update(key_ref_t key,
@@ -311,7 +307,7 @@ extern int key_unlink(struct key *keyring,

extern struct key *keyring_alloc(const char *description, kuid_t uid, kgid_t gid,
const struct cred *cred,
- key_perm_t perm,
+ struct key_acl *acl,
unsigned long flags,
struct key_restriction *restrict_link,
struct key *dest);
@@ -345,13 +341,18 @@ extern void key_set_timeout(struct key *, unsigned);
/*
* The permissions required on a key that we're looking up.
*/
-#define KEY_NEED_VIEW 0x01 /* Require permission to view attributes */
-#define KEY_NEED_READ 0x02 /* Require permission to read content */
-#define KEY_NEED_WRITE 0x04 /* Require permission to update / modify */
-#define KEY_NEED_SEARCH 0x08 /* Require permission to search (keyring) or find (key) */
-#define KEY_NEED_LINK 0x10 /* Require permission to link */
-#define KEY_NEED_SETATTR 0x20 /* Require permission to change attributes */
-#define KEY_NEED_ALL 0x3f /* All the above permissions */
+#define KEY_NEED_VIEW 0x001 /* Require permission to view attributes */
+#define KEY_NEED_READ 0x002 /* Require permission to read content */
+#define KEY_NEED_WRITE 0x004 /* Require permission to update / modify */
+#define KEY_NEED_SEARCH 0x008 /* Require permission to search (keyring) or find (key) */
+#define KEY_NEED_LINK 0x010 /* Require permission to link */
+#define KEY_NEED_SETSEC 0x020 /* Require permission to set owner, group, ACL */
+#define KEY_NEED_INVAL 0x040 /* Require permission to invalidate key */
+#define KEY_NEED_REVOKE 0x080 /* Require permission to revoke key */
+#define KEY_NEED_JOIN 0x100 /* Require permission to join keyring as session */
+#define KEY_NEED_CLEAR 0x200 /* Require permission to clear a keyring */
+
+#define OLD_KEY_NEED_SETATTR 0x20 /* Used to be Require permission to change attributes */

/**
* key_is_instantiated - Determine if a key has been positively instantiated
diff --git a/include/uapi/linux/keyctl.h b/include/uapi/linux/keyctl.h
index ef16df06642a..caed64c568b5 100644
--- a/include/uapi/linux/keyctl.h
+++ b/include/uapi/linux/keyctl.h
@@ -14,6 +14,70 @@

#include <linux/types.h>

+/*
+ * Keyring ACL definitions
+ */
+struct key_ace {
+ unsigned int mask;
+#define KEY_ACE_VIEW 0x00000001 /* Can describe the key */
+#define KEY_ACE_READ 0x00000002 /* Can read the key content */
+#define KEY_ACE_WRITE 0x00000004 /* Can update/modify the key content */
+#define KEY_ACE_SEARCH 0x00000008 /* Can find the key by search */
+#define KEY_ACE_LINK 0x00000010 /* Can make a link to the key */
+#define KEY_ACE_SET_SECURITY 0x00000020 /* Can set owner, group, ACL */
+#define KEY_ACE_INVAL 0x00000040 /* Can invalidate the key */
+#define KEY_ACE_REVOKE 0x00000080 /* Can revoke the key */
+#define KEY_ACE_JOIN 0x00000100 /* Can join keyring */
+#define KEY_ACE_CLEAR 0x00000200 /* Can clear keyring */
+#define KEY_ACE__ORDINARY 0x0000001f /* Ordinary permissions */
+#define KEY_ACE__PERMS 0x0fffffff
+#define KEY_ACE_SUBJECT_ID 0x10000000 /* Subject specified by ->subject_id */
+#define KEY_ACE__IDENTITY 0xf0000000
+
+ union {
+ unsigned int subject_id;
+#define KEY_ACE_EVERYONE 1 /* Everyone, including owner and group */
+#define KEY_ACE_GROUP 2 /* The key's group */
+#define KEY_ACE_OWNER 3 /* The owner of the key */
+#define KEY_ACE_POSSESSOR 4 /* Any process that possesses of the key */
+ };
+};
+
+/*
+ * Old-style permissions mask, deprecated in favour of ACL.
+ */
+#define KEY_POS_VIEW 0x01000000 /* possessor can view a key's attributes */
+#define KEY_POS_READ 0x02000000 /* possessor can read key payload / view keyring */
+#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_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_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_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_SETATTR 0x00000020
+#define KEY_OTH_ALL 0x0000003f
+
/* special process keyring shortcut IDs */
#define KEY_SPEC_THREAD_KEYRING -1 /* - key ID for thread-specific keyring */
#define KEY_SPEC_PROCESS_KEYRING -2 /* - key ID for process-specific keyring */
diff --git a/net/dns_resolver/dns_key.c b/net/dns_resolver/dns_key.c
index 8737412c7b27..2b77f834fede 100644
--- a/net/dns_resolver/dns_key.c
+++ b/net/dns_resolver/dns_key.c
@@ -45,6 +45,15 @@ const struct cred *dns_resolver_cache;

#define DNS_ERRORNO_OPTION "dnserror"

+static struct key_acl dns_keyring_acl = {
+ .usage = REFCOUNT_INIT(1),
+ .nr_ace = 2,
+ .aces = {
+ KEY_POSSESSOR_ACE(KEY_ACE_SEARCH | KEY_ACE_WRITE),
+ KEY_OWNER_ACE(KEY_ACE_VIEW | KEY_ACE_READ),
+ }
+};
+
/*
* Preparse instantiation data for a dns_resolver key.
*
@@ -279,8 +288,7 @@ static int __init init_dns_resolver(void)

keyring = keyring_alloc(".dns_resolver",
GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred,
- (KEY_POS_ALL & ~KEY_POS_SETATTR) |
- KEY_USR_VIEW | KEY_USR_READ,
+ &dns_keyring_acl,
KEY_ALLOC_NOT_IN_QUOTA, NULL, NULL);
if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
diff --git a/net/dns_resolver/dns_query.c b/net/dns_resolver/dns_query.c
index af781010753b..c09468d575d6 100644
--- a/net/dns_resolver/dns_query.c
+++ b/net/dns_resolver/dns_query.c
@@ -46,6 +46,15 @@

#include "internal.h"

+static struct key_acl dns_key_acl = {
+ .usage = REFCOUNT_INIT(1),
+ .nr_ace = 2,
+ .aces = {
+ KEY_POSSESSOR_ACE(KEY_ACE_VIEW | KEY_ACE_SEARCH | KEY_ACE_READ),
+ KEY_OWNER_ACE(KEY_ACE_VIEW),
+ }
+};
+
/**
* dns_query - Query the DNS
* @type: Query type (or NULL for straight host->IP lookup)
@@ -122,7 +131,7 @@ int dns_query(const char *type, const char *name, size_t namelen,
* add_key() to preinstall malicious redirections
*/
saved_cred = override_creds(dns_resolver_cache);
- rkey = request_key(&key_type_dns_resolver, desc, options);
+ rkey = request_key(&key_type_dns_resolver, desc, options, &dns_key_acl);
revert_creds(saved_cred);
kfree(desc);
if (IS_ERR(rkey)) {
@@ -132,8 +141,6 @@ int dns_query(const char *type, const char *name, size_t namelen,

down_read(&rkey->sem);
set_bit(KEY_FLAG_ROOT_CAN_INVAL, &rkey->flags);
- rkey->perm |= KEY_USR_VIEW;
-
ret = key_validate(rkey);
if (ret < 0)
goto put;
diff --git a/net/rxrpc/key.c b/net/rxrpc/key.c
index e7f6b8823eb6..aab697f61159 100644
--- a/net/rxrpc/key.c
+++ b/net/rxrpc/key.c
@@ -27,6 +27,14 @@
#include <keys/user-type.h>
#include "ar-internal.h"

+static struct key_acl rxrpc_null_key_acl = {
+ .usage = REFCOUNT_INIT(1),
+ .nr_ace = 1,
+ .aces = {
+ KEY_POSSESSOR_ACE(KEY_ACE_SEARCH | KEY_ACE_READ),
+ }
+};
+
static int rxrpc_vet_description_s(const char *);
static int rxrpc_preparse(struct key_preparsed_payload *);
static int rxrpc_preparse_s(struct key_preparsed_payload *);
@@ -912,7 +920,7 @@ int rxrpc_request_key(struct rxrpc_sock *rx, char __user *optval, int optlen)
if (IS_ERR(description))
return PTR_ERR(description);

- key = request_key(&key_type_rxrpc, description, NULL);
+ key = request_key(&key_type_rxrpc, description, NULL, NULL);
if (IS_ERR(key)) {
kfree(description);
_leave(" = %ld", PTR_ERR(key));
@@ -943,7 +951,7 @@ int rxrpc_server_keyring(struct rxrpc_sock *rx, char __user *optval,
if (IS_ERR(description))
return PTR_ERR(description);

- key = request_key(&key_type_keyring, description, NULL);
+ key = request_key(&key_type_keyring, description, NULL, NULL);
if (IS_ERR(key)) {
kfree(description);
_leave(" = %ld", PTR_ERR(key));
@@ -1024,7 +1032,7 @@ struct key *rxrpc_get_null_key(const char *keyname)

key = key_alloc(&key_type_rxrpc, keyname,
GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred,
- KEY_POS_SEARCH, KEY_ALLOC_NOT_IN_QUOTA, NULL);
+ &rxrpc_null_key_acl, KEY_ALLOC_NOT_IN_QUOTA, NULL);
if (IS_ERR(key))
return key;

diff --git a/security/keys/encrypted-keys/encrypted.c b/security/keys/encrypted-keys/encrypted.c
index 69855ba0d3b3..dfcc68d341f5 100644
--- a/security/keys/encrypted-keys/encrypted.c
+++ b/security/keys/encrypted-keys/encrypted.c
@@ -303,7 +303,7 @@ static struct key *request_user_key(const char *master_desc, const u8 **master_k
const struct user_key_payload *upayload;
struct key *ukey;

- ukey = request_key(&key_type_user, master_desc, NULL);
+ ukey = request_key(&key_type_user, master_desc, NULL, NULL);
if (IS_ERR(ukey))
goto error;

diff --git a/security/keys/encrypted-keys/masterkey_trusted.c b/security/keys/encrypted-keys/masterkey_trusted.c
index cbf0bc127a73..675d335c93fd 100644
--- a/security/keys/encrypted-keys/masterkey_trusted.c
+++ b/security/keys/encrypted-keys/masterkey_trusted.c
@@ -34,7 +34,7 @@ struct key *request_trusted_key(const char *trusted_desc,
struct trusted_key_payload *tpayload;
struct key *tkey;

- tkey = request_key(&key_type_trusted, trusted_desc, NULL);
+ tkey = request_key(&key_type_trusted, trusted_desc, NULL, NULL);
if (IS_ERR(tkey))
goto error;

diff --git a/security/keys/gc.c b/security/keys/gc.c
index 87cb260e4890..094eca1e1f42 100644
--- a/security/keys/gc.c
+++ b/security/keys/gc.c
@@ -155,6 +155,7 @@ static noinline void key_gc_unused_keys(struct list_head *keys)
atomic_dec(&key->user->nikeys);

key_user_put(key->user);
+ key_put_acl(key->acl);

kfree(key->description);

@@ -225,7 +226,6 @@ static void key_garbage_collector(struct work_struct *work)
if (key->type == key_gc_dead_keytype) {
gc_state |= KEY_GC_FOUND_DEAD_KEY;
set_bit(KEY_FLAG_DEAD, &key->flags);
- key->perm = 0;
goto skip_dead_key;
} else if (key->type == &key_type_keyring &&
key->restrict_link) {
diff --git a/security/keys/internal.h b/security/keys/internal.h
index 503adbae7b0d..2123727f2751 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -88,7 +88,8 @@ extern struct rb_root key_serial_tree;
extern spinlock_t key_serial_lock;
extern struct mutex key_construction_mutex;
extern wait_queue_head_t request_key_conswq;
-
+extern struct key_acl default_key_acl;
+extern struct key_acl joinable_keyring_acl;

extern struct key_type *key_type_lookup(const char *type);
extern void key_type_put(struct key_type *ktype);
@@ -153,13 +154,14 @@ extern struct key *request_key_and_link(struct key_type *type,
const void *callout_info,
size_t callout_len,
void *aux,
+ struct key_acl *acl,
struct key *dest_keyring,
unsigned long flags);

extern bool lookup_user_key_possessed(const struct key *key,
const struct key_match_data *match_data);
extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
- key_perm_t perm);
+ u32 desired_perm);
#define KEY_LOOKUP_CREATE 0x01
#define KEY_LOOKUP_PARTIAL 0x02
#define KEY_LOOKUP_FOR_UNLINK 0x04
@@ -178,7 +180,9 @@ extern void key_gc_keytype(struct key_type *ktype);

extern int key_task_permission(const key_ref_t key_ref,
const struct cred *cred,
- key_perm_t perm);
+ u32 desired_perm);
+extern unsigned int key_acl_to_perm(const struct key_acl *acl);
+extern void key_put_acl(struct key_acl *acl);

/*
* Check to see whether permission is granted to use a key in the desired way.
@@ -234,7 +238,7 @@ extern long keyctl_keyring_search(key_serial_t, const char __user *,
const char __user *, key_serial_t);
extern long keyctl_read_key(key_serial_t, char __user *, size_t);
extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
-extern long keyctl_setperm_key(key_serial_t, key_perm_t);
+extern long keyctl_setperm_key(key_serial_t, unsigned int);
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);
@@ -298,6 +302,7 @@ static inline long compat_keyctl_dh_compute(
#endif
#endif

+
/*
* Debugging key validation
*/
diff --git a/security/keys/key.c b/security/keys/key.c
index eb914a838840..f342bf586006 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -199,7 +199,7 @@ static inline void key_alloc_serial(struct key *key)
* @uid: The owner of the new key.
* @gid: The group ID for the new key's group permissions.
* @cred: The credentials specifying UID namespace.
- * @perm: The permissions mask of the new key.
+ * @acl: The ACL to attach to the new key.
* @flags: Flags specifying quota properties.
* @restrict_link: Optional link restriction for new keyrings.
*
@@ -227,7 +227,7 @@ static inline void key_alloc_serial(struct key *key)
*/
struct key *key_alloc(struct key_type *type, const char *desc,
kuid_t uid, kgid_t gid, const struct cred *cred,
- key_perm_t perm, unsigned long flags,
+ struct key_acl *acl, unsigned long flags,
struct key_restriction *restrict_link)
{
struct key_user *user = NULL;
@@ -250,6 +250,9 @@ struct key *key_alloc(struct key_type *type, const char *desc,
desclen = strlen(desc);
quotalen = desclen + 1 + type->def_datalen;

+ if (!acl)
+ acl = &default_key_acl;
+
/* get hold of the key tracking for this user */
user = key_user_lookup(uid);
if (!user)
@@ -295,7 +298,8 @@ struct key *key_alloc(struct key_type *type, const char *desc,
key->datalen = type->def_datalen;
key->uid = uid;
key->gid = gid;
- key->perm = perm;
+ refcount_inc(&acl->usage);
+ rcu_assign_pointer(key->acl, acl);
key->restrict_link = restrict_link;

if (!(flags & KEY_ALLOC_NOT_IN_QUOTA))
@@ -775,7 +779,7 @@ static inline key_ref_t __key_update(key_ref_t key_ref,
* @description: The searchable description for the key.
* @payload: The data to use to instantiate or update the key.
* @plen: The length of @payload.
- * @perm: The permissions mask for a new key.
+ * @acl: The ACL to attach if a key is created.
* @flags: The quota flags for a new key.
*
* Search the destination keyring for a key of the same description and if one
@@ -798,7 +802,7 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
const char *description,
const void *payload,
size_t plen,
- key_perm_t perm,
+ struct key_acl *acl,
unsigned long flags)
{
struct keyring_index_key index_key = {
@@ -889,22 +893,9 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
goto found_matching_key;
}

- /* if the client doesn't provide, decide on the permissions we want */
- if (perm == KEY_PERM_UNDEF) {
- perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR;
- perm |= KEY_USR_VIEW;
-
- if (index_key.type->read)
- perm |= KEY_POS_READ;
-
- if (index_key.type == &key_type_keyring ||
- index_key.type->update)
- perm |= KEY_POS_WRITE;
- }
-
/* allocate a new key */
key = key_alloc(index_key.type, index_key.description,
- cred->fsuid, cred->fsgid, cred, perm, flags, NULL);
+ cred->fsuid, cred->fsgid, cred, acl, flags, NULL);
if (IS_ERR(key)) {
key_ref = ERR_CAST(key);
goto error_link_end;
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 365ff85d7e27..965c7907718a 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -120,8 +120,7 @@ SYSCALL_DEFINE5(add_key, const char __user *, _type,
/* create or update the requested key and add it to the target
* keyring */
key_ref = key_create_or_update(keyring_ref, type, description,
- payload, plen, KEY_PERM_UNDEF,
- KEY_ALLOC_IN_QUOTA);
+ payload, plen, NULL, KEY_ALLOC_IN_QUOTA);
if (!IS_ERR(key_ref)) {
ret = key_ref_to_ptr(key_ref)->serial;
key_ref_put(key_ref);
@@ -211,7 +210,8 @@ SYSCALL_DEFINE4(request_key, const char __user *, _type,

/* do the search */
key = request_key_and_link(ktype, description, callout_info,
- callout_len, NULL, key_ref_to_ptr(dest_ref),
+ callout_len, NULL, NULL,
+ key_ref_to_ptr(dest_ref),
KEY_ALLOC_IN_QUOTA);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
@@ -373,16 +373,10 @@ long keyctl_revoke_key(key_serial_t id)
struct key *key;
long ret;

- key_ref = lookup_user_key(id, 0, KEY_NEED_WRITE);
+ key_ref = lookup_user_key(id, 0, KEY_NEED_REVOKE);
if (IS_ERR(key_ref)) {
ret = PTR_ERR(key_ref);
- if (ret != -EACCES)
- goto error;
- key_ref = lookup_user_key(id, 0, KEY_NEED_SETATTR);
- if (IS_ERR(key_ref)) {
- ret = PTR_ERR(key_ref);
- goto error;
- }
+ goto error;
}

key = key_ref_to_ptr(key_ref);
@@ -416,7 +410,7 @@ long keyctl_invalidate_key(key_serial_t id)

kenter("%d", id);

- key_ref = lookup_user_key(id, 0, KEY_NEED_SEARCH);
+ key_ref = lookup_user_key(id, 0, KEY_NEED_INVAL);
if (IS_ERR(key_ref)) {
ret = PTR_ERR(key_ref);

@@ -461,7 +455,7 @@ long keyctl_keyring_clear(key_serial_t ringid)
struct key *keyring;
long ret;

- keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE);
+ keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_CLEAR);
if (IS_ERR(keyring_ref)) {
ret = PTR_ERR(keyring_ref);

@@ -590,6 +584,7 @@ long keyctl_describe_key(key_serial_t keyid,
size_t buflen)
{
struct key *key, *instkey;
+ unsigned int perm;
key_ref_t key_ref;
char *infobuf;
long ret;
@@ -619,6 +614,10 @@ long keyctl_describe_key(key_serial_t keyid,
key = key_ref_to_ptr(key_ref);
desclen = strlen(key->description);

+ rcu_read_lock();
+ perm = key_acl_to_perm(rcu_dereference(key->acl));
+ rcu_read_unlock();
+
/* calculate how much information we're going to return */
ret = -ENOMEM;
infobuf = kasprintf(GFP_KERNEL,
@@ -626,7 +625,7 @@ long keyctl_describe_key(key_serial_t keyid,
key->type->name,
from_kuid_munged(current_user_ns(), key->uid),
from_kgid_munged(current_user_ns(), key->gid),
- key->perm);
+ perm);
if (!infobuf)
goto error2;
infolen = strlen(infobuf);
@@ -844,7 +843,7 @@ long keyctl_chown_key(key_serial_t id, uid_t user, gid_t group)
goto error;

key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
- KEY_NEED_SETATTR);
+ KEY_NEED_SETSEC);
if (IS_ERR(key_ref)) {
ret = PTR_ERR(key_ref);
goto error;
@@ -939,18 +938,25 @@ long keyctl_chown_key(key_serial_t id, uid_t user, gid_t group)
* the key need not be fully instantiated yet. If the caller does not have
* sysadmin capability, it may only change the permission on keys that it owns.
*/
-long keyctl_setperm_key(key_serial_t id, key_perm_t perm)
+long keyctl_setperm_key(key_serial_t id, unsigned int perm)
{
+ struct key_acl *acl, *discard;
struct key *key;
key_ref_t key_ref;
long ret;
+ int nr, i, j;

- ret = -EINVAL;
if (perm & ~(KEY_POS_ALL | KEY_USR_ALL | KEY_GRP_ALL | KEY_OTH_ALL))
- goto error;
+ return -EINVAL;
+
+ nr = 0;
+ if (perm & KEY_POS_ALL) nr++;
+ if (perm & KEY_USR_ALL) nr++;
+ if (perm & KEY_GRP_ALL) nr++;
+ if (perm & KEY_OTH_ALL) nr++;

key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
- KEY_NEED_SETATTR);
+ KEY_NEED_SETSEC);
if (IS_ERR(key_ref)) {
ret = PTR_ERR(key_ref);
goto error;
@@ -958,17 +964,56 @@ long keyctl_setperm_key(key_serial_t id, key_perm_t perm)

key = key_ref_to_ptr(key_ref);

+ ret = -EOPNOTSUPP;
+ if (test_bit(KEY_FLAG_HAS_ACL, &key->flags))
+ goto error_key;
+
+ ret = -ENOMEM;
+ acl = kzalloc(sizeof(struct key_acl) + sizeof(struct kernel_key_ace) * nr,
+ GFP_KERNEL);
+ if (!acl)
+ goto error_key;
+
+ refcount_set(&acl->usage, 1);
+ acl->nr_ace = nr;
+ j = 0;
+ for (i = 0; i < 4; i++) {
+ struct kernel_key_ace *ace = &acl->aces[j];
+ unsigned int subset = (perm >> (i * 8)) & KEY_OTH_ALL;
+
+ if (!subset)
+ continue;
+ ace->subject_id = KEY_ACE_EVERYONE + i;
+ ace->mask = KEY_ACE_SUBJECT_ID | subset;
+ if (subset & (KEY_OTH_WRITE | KEY_OTH_SETATTR))
+ ace->mask |= KEY_ACE_REVOKE;
+ if (subset & KEY_OTH_SEARCH)
+ ace->mask |= KEY_ACE_INVAL;
+ if (key->type == &key_type_keyring) {
+ if (subset & KEY_OTH_SEARCH)
+ ace->mask |= KEY_ACE_JOIN;
+ if (subset & KEY_OTH_WRITE)
+ ace->mask |= KEY_ACE_CLEAR;
+ }
+ j++;
+ }
+
/* make the changes with the locks held to prevent chown/chmod races */
+ discard = acl;
ret = -EACCES;
down_write(&key->sem);

/* if we're not the sysadmin, we can only change a key that we own */
if (capable(CAP_SYS_ADMIN) || uid_eq(key->uid, current_fsuid())) {
- key->perm = perm;
+ discard = rcu_dereference_protected(key->acl,
+ lockdep_is_held(&key->sem));
+ rcu_assign_pointer(key->acl, acl);
ret = 0;
}

up_write(&key->sem);
+ key_put_acl(discard);
+error_key:
key_put(key);
error:
return ret;
@@ -1333,7 +1378,7 @@ long keyctl_set_timeout(key_serial_t id, unsigned timeout)
long ret;

key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
- KEY_NEED_SETATTR);
+ KEY_NEED_SETSEC);
if (IS_ERR(key_ref)) {
/* setting the timeout on a key under construction is permitted
* if we have the authorisation token handy */
@@ -1604,7 +1649,7 @@ long keyctl_restrict_keyring(key_serial_t id, const char __user *_type,
char *restriction = NULL;
long ret;

- key_ref = lookup_user_key(id, 0, KEY_NEED_SETATTR);
+ key_ref = lookup_user_key(id, 0, KEY_NEED_SETSEC);
if (IS_ERR(key_ref))
return PTR_ERR(key_ref);

@@ -1692,7 +1737,7 @@ SYSCALL_DEFINE5(keyctl, int, option, unsigned long, arg2, unsigned long, arg3,

case KEYCTL_SETPERM:
return keyctl_setperm_key((key_serial_t) arg2,
- (key_perm_t) arg3);
+ (unsigned int)arg3);

case KEYCTL_INSTANTIATE:
return keyctl_instantiate_key((key_serial_t) arg2,
diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index 4fa82a8a9c0e..a2c997b89783 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -489,11 +489,19 @@ static long keyring_read(const struct key *keyring,
return ctx.count;
}

-/*
- * Allocate a keyring and link into the destination keyring.
+/**
+ * keyring_alloc - Allocate a keyring and link into the destination
+ * @description: The key description to allow the key to be searched out.
+ * @uid: The owner of the new key.
+ * @gid: The group ID for the new key's group permissions.
+ * @cred: The credentials specifying UID namespace.
+ * @acl: The ACL to attach to the new key.
+ * @flags: Flags specifying quota properties.
+ * @restrict_link: Optional link restriction for new keyrings.
+ * @dest: Destination keyring.
*/
struct key *keyring_alloc(const char *description, kuid_t uid, kgid_t gid,
- const struct cred *cred, key_perm_t perm,
+ const struct cred *cred, struct key_acl *acl,
unsigned long flags,
struct key_restriction *restrict_link,
struct key *dest)
@@ -502,7 +510,7 @@ struct key *keyring_alloc(const char *description, kuid_t uid, kgid_t gid,
int ret;

keyring = key_alloc(&key_type_keyring, description,
- uid, gid, cred, perm, flags, restrict_link);
+ uid, gid, cred, acl, flags, restrict_link);
if (!IS_ERR(keyring)) {
ret = key_instantiate_and_link(keyring, NULL, 0, dest, NULL);
if (ret < 0) {
@@ -1097,10 +1105,11 @@ key_ref_t find_key_to_update(key_ref_t keyring_ref,
/*
* Find a keyring with the specified name.
*
- * Only keyrings that have nonzero refcount, are not revoked, and are owned by a
- * user in the current user namespace are considered. If @uid_keyring is %true,
- * the keyring additionally must have been allocated as a user or user session
- * keyring; otherwise, it must grant Search permission directly to the caller.
+ * Only keyrings that have nonzero refcount, are not revoked, and are owned by
+ * a user in the current user namespace are considered. If @uid_keyring is
+ * %true, the keyring additionally must have been allocated as a user or user
+ * session keyring; otherwise, it must grant JOIN permission directly to the
+ * caller (ie. not through possession).
*
* Returns a pointer to the keyring with the keyring's refcount having being
* incremented on success. -ENOKEY is returned if a key could not be found.
@@ -1138,8 +1147,8 @@ struct key *find_keyring_by_name(const char *name, bool uid_keyring)
&keyring->flags))
continue;
} else {
- if (key_permission(make_key_ref(keyring, 0),
- KEY_NEED_SEARCH) < 0)
+ if (key_permission(make_key_ref(keyring, false),
+ KEY_NEED_JOIN) < 0)
continue;
}

diff --git a/security/keys/permission.c b/security/keys/permission.c
index 732cc0beffdf..1f8756ae2902 100644
--- a/security/keys/permission.c
+++ b/security/keys/permission.c
@@ -11,13 +11,33 @@

#include <linux/module.h>
#include <linux/security.h>
+#include <linux/user_namespace.h>
+#include <linux/uaccess.h>
#include "internal.h"

+struct key_acl default_key_acl = {
+ .usage = REFCOUNT_INIT(1),
+ .nr_ace = 2,
+ .aces = {
+ KEY_POSSESSOR_ACE(KEY_ACE__PERMS & ~KEY_ACE_JOIN),
+ KEY_OWNER_ACE(KEY_ACE_VIEW),
+ }
+};
+
+struct key_acl joinable_keyring_acl = {
+ .usage = REFCOUNT_INIT(1),
+ .nr_ace = 2,
+ .aces = {
+ KEY_POSSESSOR_ACE(KEY_ACE__PERMS & ~KEY_ACE_JOIN),
+ KEY_OWNER_ACE(KEY_ACE_VIEW | KEY_ACE_READ | KEY_ACE_LINK | KEY_ACE_JOIN),
+ }
+};
+
/**
* key_task_permission - Check a key can be used
* @key_ref: The key to check.
* @cred: The credentials to use.
- * @perm: The permissions to check for.
+ * @desired_perm: The permission to check for.
*
* Check to see whether permission is granted to use a key in the desired way,
* but permit the security modules to override.
@@ -28,53 +48,73 @@
* permissions bits or the LSM check.
*/
int key_task_permission(const key_ref_t key_ref, const struct cred *cred,
- unsigned perm)
+ unsigned int desired_perm)
{
- struct key *key;
- key_perm_t kperm;
- int ret;
+ const struct key_acl *acl;
+ const struct key *key;
+ unsigned int allow = 0;
+ int i;
+
+ BUILD_BUG_ON(KEY_NEED_VIEW != KEY_ACE_VIEW ||
+ KEY_NEED_READ != KEY_ACE_READ ||
+ KEY_NEED_WRITE != KEY_ACE_WRITE ||
+ KEY_NEED_SEARCH != KEY_ACE_SEARCH ||
+ KEY_NEED_LINK != KEY_ACE_LINK ||
+ KEY_NEED_SETSEC != KEY_ACE_SET_SECURITY ||
+ KEY_NEED_INVAL != KEY_ACE_INVAL ||
+ KEY_NEED_REVOKE != KEY_ACE_REVOKE ||
+ KEY_NEED_JOIN != KEY_ACE_JOIN ||
+ KEY_NEED_CLEAR != KEY_ACE_CLEAR);

key = key_ref_to_ptr(key_ref);

- /* use the second 8-bits of permissions for keys the caller owns */
- if (uid_eq(key->uid, cred->fsuid)) {
- kperm = key->perm >> 16;
- goto use_these_perms;
- }
-
- /* use the third 8-bits of permissions for keys the caller has a group
- * membership in common with */
- if (gid_valid(key->gid) && key->perm & KEY_GRP_ALL) {
- if (gid_eq(key->gid, cred->fsgid)) {
- kperm = key->perm >> 8;
- goto use_these_perms;
- }
-
- ret = groups_search(cred->group_info, key->gid);
- if (ret) {
- kperm = key->perm >> 8;
- goto use_these_perms;
+ rcu_read_lock();
+
+ acl = rcu_dereference(key->acl);
+ if (!acl || acl->nr_ace == 0)
+ goto no_access_rcu;
+
+ for (i = 0; i < acl->nr_ace; i++) {
+ const struct kernel_key_ace *ace = &acl->aces[i];
+
+ switch (ace->mask & KEY_ACE__IDENTITY) {
+ case KEY_ACE_SUBJECT_ID:
+ switch (ace->subject_id) {
+ case KEY_ACE_POSSESSOR:
+ if (is_key_possessed(key_ref))
+ allow |= ace->mask;
+ break;
+ case KEY_ACE_OWNER:
+ if (uid_eq(key->uid, cred->fsuid))
+ allow |= ace->mask;
+ break;
+ case KEY_ACE_GROUP:
+ if (gid_valid(key->gid)) {
+ if (gid_eq(key->gid, cred->fsgid))
+ allow |= ace->mask;
+ else if (groups_search(cred->group_info, key->gid))
+ allow |= ace->mask;
+ }
+ break;
+ case KEY_ACE_EVERYONE:
+ allow |= ace->mask;
+ break;
+ }
+ break;
}
}

- /* otherwise use the least-significant 8-bits */
- kperm = key->perm;
-
-use_these_perms:
+ rcu_read_unlock();

- /* use the top 8-bits of permissions for keys the caller possesses
- * - possessor permissions are additive with other permissions
- */
- if (is_key_possessed(key_ref))
- kperm |= key->perm >> 24;
+ if (!(allow & desired_perm))
+ goto no_access;

- kperm = kperm & perm & KEY_NEED_ALL;
+ return security_key_permission(key_ref, cred, desired_perm);

- if (kperm != perm)
- return -EACCES;
-
- /* let LSM be the final arbiter */
- return security_key_permission(key_ref, cred, perm);
+no_access_rcu:
+ rcu_read_unlock();
+no_access:
+ return -EACCES;
}
EXPORT_SYMBOL(key_task_permission);

@@ -108,3 +148,72 @@ int key_validate(const struct key *key)
return 0;
}
EXPORT_SYMBOL(key_validate);
+
+/*
+ * Roughly render an ACL to an old-style permissions mask. We cannot
+ * accurately render what the ACL, particularly if it has ACEs that represent
+ * subjects outside of { poss, user, group, other }.
+ */
+unsigned int key_acl_to_perm(const struct key_acl *acl)
+{
+ unsigned int perm = 0, tperm;
+ int i;
+
+ BUILD_BUG_ON(KEY_OTH_VIEW != KEY_ACE_VIEW ||
+ KEY_OTH_READ != KEY_ACE_READ ||
+ KEY_OTH_WRITE != KEY_ACE_WRITE ||
+ KEY_OTH_SEARCH != KEY_ACE_SEARCH ||
+ KEY_OTH_LINK != KEY_ACE_LINK ||
+ KEY_OTH_SETATTR != KEY_ACE_SET_SECURITY);
+
+ if (!acl || acl->nr_ace == 0)
+ return 0;
+
+ for (i = 0; i < acl->nr_ace; i++) {
+ const struct kernel_key_ace *ace = &acl->aces[i];
+ unsigned int mask = ace->mask & KEY_ACE__PERMS;
+
+ switch (ace->mask & KEY_ACE__IDENTITY) {
+ case KEY_ACE_SUBJECT_ID:
+ tperm = mask & KEY_OTH_ALL;
+
+ /* Invalidation and joining were allowed by SEARCH */
+ if (mask & (KEY_ACE_INVAL | KEY_ACE_JOIN))
+ tperm |= KEY_OTH_SEARCH;
+
+ /* Revocation was allowed by either SETATTR or WRITE */
+ if ((mask & KEY_ACE_REVOKE) && !(tperm & KEY_OTH_SETATTR))
+ tperm |= KEY_OTH_WRITE;
+
+ /* Clearing was allowed by WRITE */
+ if (mask & KEY_ACE_CLEAR)
+ tperm |= KEY_OTH_WRITE;
+
+ switch (ace->subject_id) {
+ case KEY_ACE_POSSESSOR:
+ perm |= tperm << 24;
+ break;
+ case KEY_ACE_OWNER:
+ perm |= tperm << 16;
+ break;
+ case KEY_ACE_GROUP:
+ perm |= tperm << 8;
+ break;
+ case KEY_ACE_EVERYONE:
+ perm |= tperm << 0;
+ break;
+ }
+ }
+ }
+
+ return perm;
+}
+
+/*
+ * Destroy a key's ACL.
+ */
+void key_put_acl(struct key_acl *acl)
+{
+ if (refcount_dec_and_test(&acl->usage))
+ kfree_rcu(acl, rcu);
+}
diff --git a/security/keys/persistent.c b/security/keys/persistent.c
index d0cb5b32eff7..260bb44e0e4e 100644
--- a/security/keys/persistent.c
+++ b/security/keys/persistent.c
@@ -16,6 +16,24 @@

unsigned persistent_keyring_expiry = 3 * 24 * 3600; /* Expire after 3 days of non-use */

+static struct key_acl persistent_register_keyring_acl = {
+ .usage = REFCOUNT_INIT(1),
+ .nr_ace = 2,
+ .aces = {
+ KEY_POSSESSOR_ACE(KEY_ACE_SEARCH | KEY_ACE_WRITE),
+ KEY_OWNER_ACE(KEY_ACE_VIEW | KEY_ACE_READ),
+ }
+};
+
+static struct key_acl persistent_keyring_acl = {
+ .usage = REFCOUNT_INIT(1),
+ .nr_ace = 2,
+ .aces = {
+ KEY_POSSESSOR_ACE(KEY_ACE__ORDINARY | KEY_ACE_CLEAR | KEY_ACE_INVAL),
+ KEY_OWNER_ACE(KEY_ACE_VIEW | KEY_ACE_READ),
+ }
+};
+
/*
* Create the persistent keyring register for the current user namespace.
*
@@ -26,8 +44,7 @@ static int key_create_persistent_register(struct user_namespace *ns)
struct key *reg = keyring_alloc(".persistent_register",
KUIDT_INIT(0), KGIDT_INIT(0),
current_cred(),
- ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
- KEY_USR_VIEW | KEY_USR_READ),
+ &persistent_register_keyring_acl,
KEY_ALLOC_NOT_IN_QUOTA, NULL, NULL);
if (IS_ERR(reg))
return PTR_ERR(reg);
@@ -60,8 +77,7 @@ static key_ref_t key_create_persistent(struct user_namespace *ns, kuid_t uid,

persistent = keyring_alloc(index_key->description,
uid, INVALID_GID, current_cred(),
- ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
- KEY_USR_VIEW | KEY_USR_READ),
+ &persistent_keyring_acl,
KEY_ALLOC_NOT_IN_QUOTA, NULL,
ns->persistent_keyring_register);
if (IS_ERR(persistent))
diff --git a/security/keys/proc.c b/security/keys/proc.c
index de834309d100..2621436b4183 100644
--- a/security/keys/proc.c
+++ b/security/keys/proc.c
@@ -176,13 +176,15 @@ static void proc_keys_stop(struct seq_file *p, void *v)

static int proc_keys_show(struct seq_file *m, void *v)
{
+ const struct key_acl *acl;
struct rb_node *_p = v;
struct key *key = rb_entry(_p, struct key, serial_node);
struct timespec now;
unsigned long timo;
key_ref_t key_ref, skey_ref;
char xbuf[16];
- int rc;
+ bool check_pos;
+ int i, rc;

struct keyring_search_context ctx = {
.index_key.type = key->type,
@@ -194,12 +196,25 @@ static int proc_keys_show(struct seq_file *m, void *v)
.flags = KEYRING_SEARCH_NO_STATE_CHECK,
};

- key_ref = make_key_ref(key, 0);
+ rcu_read_lock();
+
+ acl = rcu_dereference(key->acl);
+ check_pos = false;
+ for (i = 0; i < acl->nr_ace; i++) {
+ const struct kernel_key_ace *ace = &acl->aces[i];
+ if ((ace->mask & KEY_ACE__IDENTITY) &&
+ ace->subject_id == KEY_ACE_POSSESSOR) {
+ if (ace->mask & KEY_ACE_VIEW)
+ check_pos = true;
+ break;
+ }
+ }

/* determine if the key is possessed by this process (a test we can
* skip if the key does not indicate the possessor can view it
*/
- if (key->perm & KEY_POS_VIEW) {
+ key_ref = make_key_ref(key, 0);
+ if (check_pos) {
skey_ref = search_my_process_keyrings(&ctx);
if (!IS_ERR(skey_ref)) {
key_ref_put(skey_ref);
@@ -210,12 +225,10 @@ static int proc_keys_show(struct seq_file *m, void *v)
/* check whether the current task is allowed to view the key */
rc = key_task_permission(key_ref, ctx.cred, KEY_NEED_VIEW);
if (rc < 0)
- return 0;
+ goto out;

now = current_kernel_time();

- rcu_read_lock();
-
/* come up with a suitable timeout value */
if (key->expiry == 0) {
memcpy(xbuf, "perm", 5);
@@ -250,7 +263,7 @@ static int proc_keys_show(struct seq_file *m, void *v)
showflag(key, 'i', KEY_FLAG_INVALIDATED),
refcount_read(&key->usage),
xbuf,
- key->perm,
+ key_acl_to_perm(acl),
from_kuid_munged(seq_user_ns(m), key->uid),
from_kgid_munged(seq_user_ns(m), key->gid),
key->type->name);
@@ -261,6 +274,7 @@ static int proc_keys_show(struct seq_file *m, void *v)
key->type->describe(key, m);
seq_putc(m, '\n');

+out:
rcu_read_unlock();
return 0;
}
diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index 293d3598153b..4852e0c63d99 100644
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -38,6 +38,33 @@ struct key_user root_key_user = {
.uid = GLOBAL_ROOT_UID,
};

+static struct key_acl user_keyring_acl = {
+ .usage = REFCOUNT_INIT(1),
+ .nr_ace = 2,
+ .aces = {
+ KEY_POSSESSOR_ACE(KEY_ACE__ORDINARY),
+ KEY_OWNER_ACE(KEY_ACE__PERMS & ~(KEY_ACE_JOIN | KEY_ACE_SET_SECURITY)),
+ }
+};
+
+static struct key_acl session_keyring_acl = {
+ .usage = REFCOUNT_INIT(1),
+ .nr_ace = 2,
+ .aces = {
+ KEY_POSSESSOR_ACE(KEY_ACE__PERMS & ~KEY_ACE_JOIN),
+ KEY_OWNER_ACE(KEY_ACE_VIEW | KEY_ACE_READ),
+ }
+};
+
+static struct key_acl thread_and_process_keyring_acl = {
+ .usage = REFCOUNT_INIT(1),
+ .nr_ace = 2,
+ .aces = {
+ KEY_POSSESSOR_ACE(KEY_ACE__PERMS & ~(KEY_ACE_JOIN | KEY_ACE_SET_SECURITY)),
+ KEY_OWNER_ACE(KEY_ACE_VIEW),
+ }
+};
+
/*
* Install the user and user session keyrings for the current process's UID.
*/
@@ -46,12 +73,10 @@ int install_user_keyrings(void)
struct user_struct *user;
const struct cred *cred;
struct key *uid_keyring, *session_keyring;
- key_perm_t user_keyring_perm;
char buf[20];
int ret;
uid_t uid;

- user_keyring_perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL;
cred = current_cred();
user = cred->user;
uid = from_kuid(cred->user_ns, user->uid);
@@ -76,9 +101,9 @@ int install_user_keyrings(void)
uid_keyring = find_keyring_by_name(buf, true);
if (IS_ERR(uid_keyring)) {
uid_keyring = keyring_alloc(buf, user->uid, INVALID_GID,
- cred, user_keyring_perm,
+ cred, &user_keyring_acl,
KEY_ALLOC_UID_KEYRING |
- KEY_ALLOC_IN_QUOTA,
+ KEY_ALLOC_IN_QUOTA,
NULL, NULL);
if (IS_ERR(uid_keyring)) {
ret = PTR_ERR(uid_keyring);
@@ -94,9 +119,9 @@ int install_user_keyrings(void)
if (IS_ERR(session_keyring)) {
session_keyring =
keyring_alloc(buf, user->uid, INVALID_GID,
- cred, user_keyring_perm,
+ cred, &user_keyring_acl,
KEY_ALLOC_UID_KEYRING |
- KEY_ALLOC_IN_QUOTA,
+ KEY_ALLOC_IN_QUOTA,
NULL, NULL);
if (IS_ERR(session_keyring)) {
ret = PTR_ERR(session_keyring);
@@ -143,7 +168,7 @@ int install_thread_keyring_to_cred(struct cred *new)
return 0;

keyring = keyring_alloc("_tid", new->uid, new->gid, new,
- KEY_POS_ALL | KEY_USR_VIEW,
+ &thread_and_process_keyring_acl,
KEY_ALLOC_QUOTA_OVERRUN,
NULL, NULL);
if (IS_ERR(keyring))
@@ -190,7 +215,7 @@ int install_process_keyring_to_cred(struct cred *new)
return 0;

keyring = keyring_alloc("_pid", new->uid, new->gid, new,
- KEY_POS_ALL | KEY_USR_VIEW,
+ &thread_and_process_keyring_acl,
KEY_ALLOC_QUOTA_OVERRUN,
NULL, NULL);
if (IS_ERR(keyring))
@@ -244,8 +269,7 @@ int install_session_keyring_to_cred(struct cred *cred, struct key *keyring)
flags = KEY_ALLOC_IN_QUOTA;

keyring = keyring_alloc("_ses", cred->uid, cred->gid, cred,
- KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ,
- flags, NULL, NULL);
+ &session_keyring_acl, flags, NULL, NULL);
if (IS_ERR(keyring))
return PTR_ERR(keyring);
} else {
@@ -531,7 +555,7 @@ bool lookup_user_key_possessed(const struct key *key,
* returned key reference.
*/
key_ref_t lookup_user_key(key_serial_t id, unsigned long lflags,
- key_perm_t perm)
+ unsigned int desired_perm)
{
struct keyring_search_context ctx = {
.match_data.cmp = lookup_user_key_possessed,
@@ -717,12 +741,12 @@ key_ref_t lookup_user_key(key_serial_t id, unsigned long lflags,
case -ERESTARTSYS:
goto invalid_key;
default:
- if (perm)
+ if (desired_perm)
goto invalid_key;
case 0:
break;
}
- } else if (perm) {
+ } else if (desired_perm) {
ret = key_validate(key);
if (ret < 0)
goto invalid_key;
@@ -734,9 +758,11 @@ key_ref_t lookup_user_key(key_serial_t id, unsigned long lflags,
goto invalid_key;

/* check the permissions */
- ret = key_task_permission(key_ref, ctx.cred, perm);
- if (ret < 0)
- goto invalid_key;
+ if (desired_perm) {
+ ret = key_task_permission(key_ref, ctx.cred, desired_perm);
+ if (ret < 0)
+ goto invalid_key;
+ }

key->last_used_at = current_kernel_time().tv_sec;

@@ -800,13 +826,13 @@ long join_session_keyring(const char *name)
if (PTR_ERR(keyring) == -ENOKEY) {
/* not found - try and create a new one */
keyring = keyring_alloc(
- name, old->uid, old->gid, old,
- KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ | KEY_USR_LINK,
+ name, old->uid, old->gid, old, &joinable_keyring_acl,
KEY_ALLOC_IN_QUOTA, NULL, NULL);
if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
goto error2;
}
+ goto no_perm_test;
} else if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
goto error2;
@@ -815,6 +841,12 @@ long join_session_keyring(const char *name)
goto error3;
}

+ ret = key_task_permission(make_key_ref(keyring, false), old,
+ KEY_NEED_JOIN);
+ if (ret < 0)
+ goto error3;
+
+no_perm_test:
/* we've got a keyring - now to install it */
ret = install_session_keyring_to_cred(new, keyring);
if (ret < 0)
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index 63e63a42db3c..2f7906c231a6 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -116,8 +116,7 @@ static int call_sbin_request_key(struct key_construction *cons,

cred = get_current_cred();
keyring = keyring_alloc(desc, cred->fsuid, cred->fsgid, cred,
- KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ,
- KEY_ALLOC_QUOTA_OVERRUN, NULL, NULL);
+ NULL, KEY_ALLOC_QUOTA_OVERRUN, NULL, NULL);
put_cred(cred);
if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
@@ -332,11 +331,11 @@ static int construct_alloc_key(struct keyring_search_context *ctx,
struct key *dest_keyring,
unsigned long flags,
struct key_user *user,
+ struct key_acl *acl,
struct key **_key)
{
struct assoc_array_edit *edit;
struct key *key;
- key_perm_t perm;
key_ref_t key_ref;
int ret;

@@ -346,17 +345,9 @@ static int construct_alloc_key(struct keyring_search_context *ctx,
*_key = NULL;
mutex_lock(&user->cons_lock);

- perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR;
- perm |= KEY_USR_VIEW;
- if (ctx->index_key.type->read)
- perm |= KEY_POS_READ;
- if (ctx->index_key.type == &key_type_keyring ||
- ctx->index_key.type->update)
- perm |= KEY_POS_WRITE;
-
key = key_alloc(ctx->index_key.type, ctx->index_key.description,
ctx->cred->fsuid, ctx->cred->fsgid, ctx->cred,
- perm, flags, NULL);
+ NULL, flags, NULL);
if (IS_ERR(key))
goto alloc_failed;

@@ -432,6 +423,7 @@ static struct key *construct_key_and_link(struct keyring_search_context *ctx,
const char *callout_info,
size_t callout_len,
void *aux,
+ struct key_acl *acl,
struct key *dest_keyring,
unsigned long flags)
{
@@ -450,7 +442,7 @@ static struct key *construct_key_and_link(struct keyring_search_context *ctx,

construct_get_dest_keyring(&dest_keyring);

- ret = construct_alloc_key(ctx, dest_keyring, flags, user, &key);
+ ret = construct_alloc_key(ctx, dest_keyring, flags, user, acl, &key);
key_user_put(user);

if (ret == 0) {
@@ -486,6 +478,7 @@ static struct key *construct_key_and_link(struct keyring_search_context *ctx,
* @callout_info: The data to pass to the instantiation upcall (or NULL).
* @callout_len: The length of callout_info.
* @aux: Auxiliary data for the upcall.
+ * @acl: The ACL to attach if a new key is created.
* @dest_keyring: Where to cache the key.
* @flags: Flags to key_alloc().
*
@@ -511,6 +504,7 @@ struct key *request_key_and_link(struct key_type *type,
const void *callout_info,
size_t callout_len,
void *aux,
+ struct key_acl *acl,
struct key *dest_keyring,
unsigned long flags)
{
@@ -565,7 +559,7 @@ struct key *request_key_and_link(struct key_type *type,
goto error_free;

key = construct_key_and_link(&ctx, callout_info, callout_len,
- aux, dest_keyring, flags);
+ aux, acl, dest_keyring, flags);
}

error_free:
@@ -608,6 +602,7 @@ EXPORT_SYMBOL(wait_for_key_construction);
* @type: Type of key.
* @description: The searchable description of the key.
* @callout_info: The data to pass to the instantiation upcall (or NULL).
+ * @acl: The ACL to attach if a new key is created.
*
* As for request_key_and_link() except that it does not add the returned key
* to a keyring if found, new keys are always allocated in the user's quota,
@@ -619,7 +614,8 @@ EXPORT_SYMBOL(wait_for_key_construction);
*/
struct key *request_key(struct key_type *type,
const char *description,
- const char *callout_info)
+ const char *callout_info,
+ struct key_acl *acl)
{
struct key *key;
size_t callout_len = 0;
@@ -628,7 +624,7 @@ struct key *request_key(struct key_type *type,
if (callout_info)
callout_len = strlen(callout_info);
key = request_key_and_link(type, description, callout_info, callout_len,
- NULL, NULL, KEY_ALLOC_IN_QUOTA);
+ NULL, acl, NULL, KEY_ALLOC_IN_QUOTA);
if (!IS_ERR(key)) {
ret = wait_for_key_construction(key, false);
if (ret < 0) {
@@ -647,6 +643,7 @@ EXPORT_SYMBOL(request_key);
* @callout_info: The data to pass to the instantiation upcall (or NULL).
* @callout_len: The length of callout_info.
* @aux: Auxiliary data for the upcall.
+ * @acl: The ACL to attach if a new key is created.
*
* As for request_key_and_link() except that it does not add the returned key
* to a keyring if found and new keys are always allocated in the user's quota.
@@ -658,13 +655,14 @@ struct key *request_key_with_auxdata(struct key_type *type,
const char *description,
const void *callout_info,
size_t callout_len,
- void *aux)
+ void *aux,
+ struct key_acl *acl)
{
struct key *key;
int ret;

key = request_key_and_link(type, description, callout_info, callout_len,
- aux, NULL, KEY_ALLOC_IN_QUOTA);
+ aux, acl, NULL, KEY_ALLOC_IN_QUOTA);
if (!IS_ERR(key)) {
ret = wait_for_key_construction(key, false);
if (ret < 0) {
@@ -682,6 +680,7 @@ EXPORT_SYMBOL(request_key_with_auxdata);
* @description: The searchable description of the key.
* @callout_info: The data to pass to the instantiation upcall (or NULL).
* @callout_len: The length of callout_info.
+ * @acl: The ACL to attach if a new key is created.
*
* As for request_key_and_link() except that it does not add the returned key
* to a keyring if found, new keys are always allocated in the user's quota and
@@ -693,10 +692,11 @@ EXPORT_SYMBOL(request_key_with_auxdata);
struct key *request_key_async(struct key_type *type,
const char *description,
const void *callout_info,
- size_t callout_len)
+ size_t callout_len,
+ struct key_acl *acl)
{
return request_key_and_link(type, description, callout_info,
- callout_len, NULL, NULL,
+ callout_len, NULL, acl, NULL,
KEY_ALLOC_IN_QUOTA);
}
EXPORT_SYMBOL(request_key_async);
@@ -708,6 +708,7 @@ EXPORT_SYMBOL(request_key_async);
* @callout_info: The data to pass to the instantiation upcall (or NULL).
* @callout_len: The length of callout_info.
* @aux: Auxiliary data for the upcall.
+ * @acl: The ACL to attach if a new key is created.
*
* As for request_key_and_link() except that it does not add the returned key
* to a keyring if found and new keys are always allocated in the user's quota.
@@ -719,9 +720,11 @@ struct key *request_key_async_with_auxdata(struct key_type *type,
const char *description,
const void *callout_info,
size_t callout_len,
- void *aux)
+ void *aux,
+ struct key_acl *acl)
{
return request_key_and_link(type, description, callout_info,
- callout_len, aux, NULL, KEY_ALLOC_IN_QUOTA);
+ callout_len, aux, acl,
+ NULL, KEY_ALLOC_IN_QUOTA);
}
EXPORT_SYMBOL(request_key_async_with_auxdata);
diff --git a/security/keys/request_key_auth.c b/security/keys/request_key_auth.c
index 6ebf1af8fce9..3d1aa9051b57 100644
--- a/security/keys/request_key_auth.c
+++ b/security/keys/request_key_auth.c
@@ -29,6 +29,15 @@ static void request_key_auth_revoke(struct key *);
static void request_key_auth_destroy(struct key *);
static long request_key_auth_read(const struct key *, char __user *, size_t);

+static struct key_acl request_key_auth_acl = {
+ .usage = REFCOUNT_INIT(1),
+ .nr_ace = 2,
+ .aces = {
+ KEY_POSSESSOR_ACE(KEY_ACE_VIEW | KEY_ACE_READ | KEY_ACE_SEARCH),
+ KEY_OWNER_ACE(KEY_ACE_VIEW),
+ }
+};
+
/*
* The request-key authorisation key type definition.
*/
@@ -203,8 +212,8 @@ struct key *request_key_auth_new(struct key *target, const void *callout_info,

authkey = key_alloc(&key_type_request_key_auth, desc,
cred->fsuid, cred->fsgid, cred,
- KEY_POS_VIEW | KEY_POS_READ | KEY_POS_SEARCH |
- KEY_USR_VIEW, KEY_ALLOC_NOT_IN_QUOTA, NULL);
+ &request_key_auth_acl,
+ KEY_ALLOC_NOT_IN_QUOTA, NULL);
if (IS_ERR(authkey)) {
ret = PTR_ERR(authkey);
goto error_free_rka;
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index f5d304736852..0c03bfab3322 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -6157,6 +6157,7 @@ static int selinux_key_permission(key_ref_t key_ref,
{
struct key *key;
struct key_security_struct *ksec;
+ unsigned oldstyle_perm;
u32 sid;

/* if no specific permissions are requested, we skip the
@@ -6165,12 +6166,25 @@ static int selinux_key_permission(key_ref_t key_ref,
if (perm == 0)
return 0;

+ oldstyle_perm = perm & (KEY_NEED_VIEW | KEY_NEED_READ | KEY_NEED_WRITE |
+ KEY_NEED_SEARCH | KEY_NEED_LINK);
+ if (perm & KEY_NEED_SETSEC)
+ oldstyle_perm |= OLD_KEY_NEED_SETATTR;
+ if (perm & KEY_NEED_INVAL)
+ oldstyle_perm |= KEY_NEED_SEARCH;
+ if (perm & KEY_NEED_REVOKE && !(perm & OLD_KEY_NEED_SETATTR))
+ oldstyle_perm |= KEY_NEED_WRITE;
+ if (perm & KEY_NEED_JOIN)
+ oldstyle_perm |= KEY_NEED_SEARCH;
+ if (perm & KEY_NEED_CLEAR)
+ oldstyle_perm |= KEY_NEED_WRITE;
+
sid = cred_sid(cred);

key = key_ref_to_ptr(key_ref);
ksec = key->security;

- return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL);
+ return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, oldstyle_perm, NULL);
}

static int selinux_key_getsecurity(struct key *key, char **_buffer)
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 319add31b4a4..2cd323206310 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -4377,7 +4377,8 @@ static int smack_key_permission(key_ref_t key_ref,
#endif
if (perm & KEY_NEED_READ)
request = MAY_READ;
- if (perm & (KEY_NEED_WRITE | KEY_NEED_LINK | KEY_NEED_SETATTR))
+ if (perm & (KEY_NEED_WRITE | KEY_NEED_LINK | KEY_NEED_SETSEC |
+ KEY_NEED_INVAL | KEY_NEED_REVOKE | KEY_NEED_CLEAR))
request = MAY_WRITE;
rc = smk_access(tkp, keyp->security, request, &ad);
rc = smk_bu_note("key access", tkp, keyp->security, request, rc);
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