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-rw-r--r--include/linux/key.h30
-rw-r--r--include/linux/security.h6
-rw-r--r--security/keys/internal.h8
-rw-r--r--security/keys/keyctl.c16
-rw-r--r--security/keys/permission.c31
-rw-r--r--security/keys/process_keys.c46
-rw-r--r--security/security.c6
-rw-r--r--security/selinux/hooks.c37
-rw-r--r--security/smack/smack_lsm.c29
9 files changed, 135 insertions, 74 deletions
diff --git a/include/linux/key.h b/include/linux/key.h
index b99b40db08fc..0f2e24f13c2b 100644
--- a/include/linux/key.h
+++ b/include/linux/key.h
@@ -71,6 +71,23 @@ struct net;
#define KEY_PERM_UNDEF 0xffffffff
+/*
+ * The permissions required on a key that we're looking up.
+ */
+enum key_need_perm {
+ KEY_NEED_UNSPECIFIED, /* Needed permission unspecified */
+ KEY_NEED_VIEW, /* Require permission to view attributes */
+ KEY_NEED_READ, /* Require permission to read content */
+ KEY_NEED_WRITE, /* Require permission to update / modify */
+ KEY_NEED_SEARCH, /* Require permission to search (keyring) or find (key) */
+ KEY_NEED_LINK, /* Require permission to link */
+ KEY_NEED_SETATTR, /* Require permission to change attributes */
+ KEY_NEED_UNLINK, /* Require permission to unlink key */
+ KEY_SYSADMIN_OVERRIDE, /* Special: override by CAP_SYS_ADMIN */
+ KEY_AUTHTOKEN_OVERRIDE, /* Special: override by possession of auth token */
+ KEY_DEFER_PERM_CHECK, /* Special: permission check is deferred */
+};
+
struct seq_file;
struct user_struct;
struct signal_struct;
@@ -420,20 +437,9 @@ static inline key_serial_t key_serial(const struct key *key)
extern void key_set_timeout(struct key *, unsigned);
extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
- key_perm_t perm);
+ enum key_need_perm need_perm);
extern void key_free_user_ns(struct user_namespace *);
-/*
- * 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 */
-
static inline short key_read_state(const struct key *key)
{
/* Barrier versus mark_key_instantiated(). */
diff --git a/include/linux/security.h b/include/linux/security.h
index e7914e4e0b02..57aac14e3418 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1767,8 +1767,8 @@ static inline int security_path_chroot(const struct path *path)
int security_key_alloc(struct key *key, const struct cred *cred, unsigned long flags);
void security_key_free(struct key *key);
-int security_key_permission(key_ref_t key_ref,
- const struct cred *cred, unsigned perm);
+int security_key_permission(key_ref_t key_ref, const struct cred *cred,
+ enum key_need_perm need_perm);
int security_key_getsecurity(struct key *key, char **_buffer);
#else
@@ -1786,7 +1786,7 @@ static inline void security_key_free(struct key *key)
static inline int security_key_permission(key_ref_t key_ref,
const struct cred *cred,
- unsigned perm)
+ enum key_need_perm need_perm)
{
return 0;
}
diff --git a/security/keys/internal.h b/security/keys/internal.h
index 28e17f4f3328..1fc17cb317a9 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -167,7 +167,6 @@ extern bool lookup_user_key_possessed(const struct key *key,
const struct key_match_data *match_data);
#define KEY_LOOKUP_CREATE 0x01
#define KEY_LOOKUP_PARTIAL 0x02
-#define KEY_LOOKUP_FOR_UNLINK 0x04
extern long join_session_keyring(const char *name);
extern void key_change_session_keyring(struct callback_head *twork);
@@ -183,7 +182,7 @@ 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);
+ enum key_need_perm need_perm);
static inline void notify_key(struct key *key,
enum key_notification_subtype subtype, u32 aux)
@@ -205,9 +204,10 @@ static inline void notify_key(struct key *key,
/*
* Check to see whether permission is granted to use a key in the desired way.
*/
-static inline int key_permission(const key_ref_t key_ref, unsigned perm)
+static inline int key_permission(const key_ref_t key_ref,
+ enum key_need_perm need_perm)
{
- return key_task_permission(key_ref, current_cred(), perm);
+ return key_task_permission(key_ref, current_cred(), need_perm);
}
extern struct key_type key_type_request_key_auth;
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 7d8de1c9a478..6763ee45e04d 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -434,7 +434,7 @@ long keyctl_invalidate_key(key_serial_t id)
/* Root is permitted to invalidate certain special keys */
if (capable(CAP_SYS_ADMIN)) {
- key_ref = lookup_user_key(id, 0, 0);
+ key_ref = lookup_user_key(id, 0, KEY_SYSADMIN_OVERRIDE);
if (IS_ERR(key_ref))
goto error;
if (test_bit(KEY_FLAG_ROOT_CAN_INVAL,
@@ -479,7 +479,8 @@ long keyctl_keyring_clear(key_serial_t ringid)
/* Root is permitted to invalidate certain special keyrings */
if (capable(CAP_SYS_ADMIN)) {
- keyring_ref = lookup_user_key(ringid, 0, 0);
+ keyring_ref = lookup_user_key(ringid, 0,
+ KEY_SYSADMIN_OVERRIDE);
if (IS_ERR(keyring_ref))
goto error;
if (test_bit(KEY_FLAG_ROOT_CAN_CLEAR,
@@ -563,7 +564,7 @@ long keyctl_keyring_unlink(key_serial_t id, key_serial_t ringid)
goto error;
}
- key_ref = lookup_user_key(id, KEY_LOOKUP_FOR_UNLINK, 0);
+ key_ref = lookup_user_key(id, KEY_LOOKUP_PARTIAL, KEY_NEED_UNLINK);
if (IS_ERR(key_ref)) {
ret = PTR_ERR(key_ref);
goto error2;
@@ -663,7 +664,7 @@ long keyctl_describe_key(key_serial_t keyid,
key_put(instkey);
key_ref = lookup_user_key(keyid,
KEY_LOOKUP_PARTIAL,
- 0);
+ KEY_AUTHTOKEN_OVERRIDE);
if (!IS_ERR(key_ref))
goto okay;
}
@@ -833,7 +834,7 @@ long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen)
size_t key_data_len;
/* find the key first */
- key_ref = lookup_user_key(keyid, 0, 0);
+ key_ref = lookup_user_key(keyid, 0, KEY_DEFER_PERM_CHECK);
if (IS_ERR(key_ref)) {
ret = -ENOKEY;
goto out;
@@ -1471,7 +1472,7 @@ long keyctl_set_timeout(key_serial_t id, unsigned timeout)
key_put(instkey);
key_ref = lookup_user_key(id,
KEY_LOOKUP_PARTIAL,
- 0);
+ KEY_AUTHTOKEN_OVERRIDE);
if (!IS_ERR(key_ref))
goto okay;
}
@@ -1579,7 +1580,8 @@ long keyctl_get_security(key_serial_t keyid,
return PTR_ERR(instkey);
key_put(instkey);
- key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, 0);
+ key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL,
+ KEY_AUTHTOKEN_OVERRIDE);
if (IS_ERR(key_ref))
return PTR_ERR(key_ref);
}
diff --git a/security/keys/permission.c b/security/keys/permission.c
index 085f907b64ac..4a61f804e80f 100644
--- a/security/keys/permission.c
+++ b/security/keys/permission.c
@@ -13,7 +13,7 @@
* 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.
+ * @need_perm: The permission required.
*
* Check to see whether permission is granted to use a key in the desired way,
* but permit the security modules to override.
@@ -24,12 +24,30 @@
* permissions bits or the LSM check.
*/
int key_task_permission(const key_ref_t key_ref, const struct cred *cred,
- unsigned perm)
+ enum key_need_perm need_perm)
{
struct key *key;
- key_perm_t kperm;
+ key_perm_t kperm, mask;
int ret;
+ switch (need_perm) {
+ default:
+ WARN_ON(1);
+ return -EACCES;
+ case KEY_NEED_UNLINK:
+ case KEY_SYSADMIN_OVERRIDE:
+ case KEY_AUTHTOKEN_OVERRIDE:
+ case KEY_DEFER_PERM_CHECK:
+ goto lsm;
+
+ case KEY_NEED_VIEW: mask = KEY_OTH_VIEW; break;
+ case KEY_NEED_READ: mask = KEY_OTH_READ; break;
+ case KEY_NEED_WRITE: mask = KEY_OTH_WRITE; break;
+ case KEY_NEED_SEARCH: mask = KEY_OTH_SEARCH; break;
+ case KEY_NEED_LINK: mask = KEY_OTH_LINK; break;
+ case KEY_NEED_SETATTR: mask = KEY_OTH_SETATTR; break;
+ }
+
key = key_ref_to_ptr(key_ref);
/* use the second 8-bits of permissions for keys the caller owns */
@@ -64,13 +82,12 @@ use_these_perms:
if (is_key_possessed(key_ref))
kperm |= key->perm >> 24;
- kperm = kperm & perm & KEY_NEED_ALL;
-
- if (kperm != perm)
+ if ((kperm & mask) != mask)
return -EACCES;
/* let LSM be the final arbiter */
- return security_key_permission(key_ref, cred, perm);
+lsm:
+ return security_key_permission(key_ref, cred, need_perm);
}
EXPORT_SYMBOL(key_task_permission);
diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index 09541de31f2f..7e0232db1707 100644
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -609,7 +609,7 @@ 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)
+ enum key_need_perm need_perm)
{
struct keyring_search_context ctx = {
.match_data.cmp = lookup_user_key_possessed,
@@ -773,35 +773,33 @@ try_again:
/* unlink does not use the nominated key in any way, so can skip all
* the permission checks as it is only concerned with the keyring */
- if (lflags & KEY_LOOKUP_FOR_UNLINK) {
- ret = 0;
- goto error;
- }
-
- if (!(lflags & KEY_LOOKUP_PARTIAL)) {
- ret = wait_for_key_construction(key, true);
- switch (ret) {
- case -ERESTARTSYS:
- goto invalid_key;
- default:
- if (perm)
+ if (need_perm != KEY_NEED_UNLINK) {
+ if (!(lflags & KEY_LOOKUP_PARTIAL)) {
+ ret = wait_for_key_construction(key, true);
+ switch (ret) {
+ case -ERESTARTSYS:
+ goto invalid_key;
+ default:
+ if (need_perm != KEY_AUTHTOKEN_OVERRIDE &&
+ need_perm != KEY_DEFER_PERM_CHECK)
+ goto invalid_key;
+ case 0:
+ break;
+ }
+ } else if (need_perm != KEY_DEFER_PERM_CHECK) {
+ ret = key_validate(key);
+ if (ret < 0)
goto invalid_key;
- case 0:
- break;
}
- } else if (perm) {
- ret = key_validate(key);
- if (ret < 0)
+
+ ret = -EIO;
+ if (!(lflags & KEY_LOOKUP_PARTIAL) &&
+ key_read_state(key) == KEY_IS_UNINSTANTIATED)
goto invalid_key;
}
- ret = -EIO;
- if (!(lflags & KEY_LOOKUP_PARTIAL) &&
- key_read_state(key) == KEY_IS_UNINSTANTIATED)
- goto invalid_key;
-
/* check the permissions */
- ret = key_task_permission(key_ref, ctx.cred, perm);
+ ret = key_task_permission(key_ref, ctx.cred, need_perm);
if (ret < 0)
goto invalid_key;
diff --git a/security/security.c b/security/security.c
index c73334ab2882..af32d4cd0462 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2398,10 +2398,10 @@ void security_key_free(struct key *key)
call_void_hook(key_free, key);
}
-int security_key_permission(key_ref_t key_ref,
- const struct cred *cred, unsigned perm)
+int security_key_permission(key_ref_t key_ref, const struct cred *cred,
+ enum key_need_perm need_perm)
{
- return call_int_hook(key_permission, 0, key_ref, cred, perm);
+ return call_int_hook(key_permission, 0, key_ref, cred, need_perm);
}
int security_key_getsecurity(struct key *key, char **_buffer)
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 4c037c2545c1..196acaccbfdd 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -6561,20 +6561,43 @@ static void selinux_key_free(struct key *k)
static int selinux_key_permission(key_ref_t key_ref,
const struct cred *cred,
- unsigned perm)
+ enum key_need_perm need_perm)
{
struct key *key;
struct key_security_struct *ksec;
- u32 sid;
+ u32 perm, sid;
- /* if no specific permissions are requested, we skip the
- permission check. No serious, additional covert channels
- appear to be created. */
- if (perm == 0)
+ switch (need_perm) {
+ case KEY_NEED_VIEW:
+ perm = KEY__VIEW;
+ break;
+ case KEY_NEED_READ:
+ perm = KEY__READ;
+ break;
+ case KEY_NEED_WRITE:
+ perm = KEY__WRITE;
+ break;
+ case KEY_NEED_SEARCH:
+ perm = KEY__SEARCH;
+ break;
+ case KEY_NEED_LINK:
+ perm = KEY__LINK;
+ break;
+ case KEY_NEED_SETATTR:
+ perm = KEY__SETATTR;
+ break;
+ case KEY_NEED_UNLINK:
+ case KEY_SYSADMIN_OVERRIDE:
+ case KEY_AUTHTOKEN_OVERRIDE:
+ case KEY_DEFER_PERM_CHECK:
return 0;
+ default:
+ WARN_ON(1);
+ return -EPERM;
- sid = cred_sid(cred);
+ }
+ sid = cred_sid(cred);
key = key_ref_to_ptr(key_ref);
ksec = key->security;
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 8c61d175e195..0d6bb53efe74 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -4230,13 +4230,14 @@ static void smack_key_free(struct key *key)
* smack_key_permission - Smack access on a key
* @key_ref: gets to the object
* @cred: the credentials to use
- * @perm: requested key permissions
+ * @need_perm: requested key permission
*
* Return 0 if the task has read and write to the object,
* an error code otherwise
*/
static int smack_key_permission(key_ref_t key_ref,
- const struct cred *cred, unsigned perm)
+ const struct cred *cred,
+ enum key_need_perm need_perm)
{
struct key *keyp;
struct smk_audit_info ad;
@@ -4247,8 +4248,26 @@ static int smack_key_permission(key_ref_t key_ref,
/*
* Validate requested permissions
*/
- if (perm & ~KEY_NEED_ALL)
+ switch (need_perm) {
+ case KEY_NEED_READ:
+ case KEY_NEED_SEARCH:
+ case KEY_NEED_VIEW:
+ request |= MAY_READ;
+ break;
+ case KEY_NEED_WRITE:
+ case KEY_NEED_LINK:
+ case KEY_NEED_SETATTR:
+ request |= MAY_WRITE;
+ break;
+ case KEY_NEED_UNSPECIFIED:
+ case KEY_NEED_UNLINK:
+ case KEY_SYSADMIN_OVERRIDE:
+ case KEY_AUTHTOKEN_OVERRIDE:
+ case KEY_DEFER_PERM_CHECK:
+ return 0;
+ default:
return -EINVAL;
+ }
keyp = key_ref_to_ptr(key_ref);
if (keyp == NULL)
@@ -4273,10 +4292,6 @@ static int smack_key_permission(key_ref_t key_ref,
ad.a.u.key_struct.key = keyp->serial;
ad.a.u.key_struct.key_desc = keyp->description;
#endif
- if (perm & (KEY_NEED_READ | KEY_NEED_SEARCH | KEY_NEED_VIEW))
- request |= MAY_READ;
- if (perm & (KEY_NEED_WRITE | KEY_NEED_LINK | KEY_NEED_SETATTR))
- request |= MAY_WRITE;
rc = smk_access(tkp, keyp->security, request, &ad);
rc = smk_bu_note("key access", tkp, keyp->security, request, rc);
return rc;