From a4e3b8d79a5c6d40f4a9703abf7fe3abcc6c3b8d Mon Sep 17 00:00:00 2001
From: Mimi Zohar <zohar@linux.vnet.ibm.com>
Date: Thu, 22 May 2014 14:02:23 -0400
Subject: KEYS: special dot prefixed keyring name bug fix
Dot prefixed keyring names are supposed to be reserved for the
kernel, but add_key() calls key_get_type_from_user(), which
incorrectly verifies the 'type' field, not the 'description' field.
This patch verifies the 'description' field isn't dot prefixed,
when creating a new keyring, and removes the dot prefix test in
key_get_type_from_user().
Changelog v6:
- whitespace and other cleanup
Changelog v5:
- Only prevent userspace from creating a dot prefixed keyring, not
regular keys - Dmitry
Reported-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>
---
security/keys/keyctl.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
(limited to 'security')
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index cd5bd0cef25d..8a8c23357291 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -37,8 +37,6 @@ static int key_get_type_from_user(char *type,
return ret;
if (ret == 0 || ret >= len)
return -EINVAL;
- if (type[0] == '.')
- return -EPERM;
type[len - 1] = '\0';
return 0;
}
@@ -86,6 +84,10 @@ SYSCALL_DEFINE5(add_key, const char __user *, _type,
if (!*description) {
kfree(description);
description = NULL;
+ } else if ((description[0] == '.') &&
+ (strncmp(type, "keyring", 7) == 0)) {
+ ret = -EPERM;
+ goto error2;
}
}
--
cgit v1.2.2
From 7d2ce2320e8efdc4a6dcbae7b329ed3f0d1cd778 Mon Sep 17 00:00:00 2001
From: Mimi Zohar <zohar@linux.vnet.ibm.com>
Date: Tue, 13 Aug 2013 08:47:43 -0400
Subject: ima: define '.ima' as a builtin 'trusted' keyring
Require all keys added to the IMA keyring be signed by an
existing trusted key on the system trusted keyring.
Changelog v6:
- remove ifdef CONFIG_IMA_TRUSTED_KEYRING in C code - Dmitry
- update Kconfig dependency and help
- select KEYS_DEBUG_PROC_KEYS - Dmitry
Changelog v5:
- Move integrity_init_keyring() to init_ima() - Dmitry
- reset keyring[id] on failure - Dmitry
Changelog v1:
- don't link IMA trusted keyring to user keyring
Changelog:
- define stub integrity_init_keyring() function (reported-by Fengguang Wu)
- differentiate between regular and trusted keyring names.
- replace printk with pr_info (D. Kasatkin)
- only make the IMA keyring a trusted keyring (reported-by D. Kastatkin)
- define stub integrity_init_keyring() definition based on
CONFIG_INTEGRITY_SIGNATURE, not CONFIG_INTEGRITY_ASYMMETRIC_KEYS.
(reported-by Jim Davis)
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Acked-by: David Howells <dhowells@redhat.com>
---
security/integrity/digsig.c | 28 ++++++++++++++++++++++++++++
security/integrity/ima/Kconfig | 10 ++++++++++
security/integrity/ima/ima.h | 12 ++++++++++++
security/integrity/ima/ima_main.c | 10 ++++++++--
security/integrity/integrity.h | 5 +++++
5 files changed, 63 insertions(+), 2 deletions(-)
(limited to 'security')
diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
index b4af4ebc5be2..8d4fbff8b87c 100644
--- a/security/integrity/digsig.c
+++ b/security/integrity/digsig.c
@@ -13,7 +13,9 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/err.h>
+#include <linux/sched.h>
#include <linux/rbtree.h>
+#include <linux/cred.h>
#include <linux/key-type.h>
#include <linux/digsig.h>
@@ -24,7 +26,11 @@ static struct key *keyring[INTEGRITY_KEYRING_MAX];
static const char *keyring_name[INTEGRITY_KEYRING_MAX] = {
"_evm",
"_module",
+#ifndef CONFIG_IMA_TRUSTED_KEYRING
"_ima",
+#else
+ ".ima",
+#endif
};
int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
@@ -56,3 +62,25 @@ int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
return -EOPNOTSUPP;
}
+
+int integrity_init_keyring(const unsigned int id)
+{
+ const struct cred *cred = current_cred();
+ int err = 0;
+
+ keyring[id] = keyring_alloc(keyring_name[id], KUIDT_INIT(0),
+ KGIDT_INIT(0), cred,
+ ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
+ KEY_USR_VIEW | KEY_USR_READ |
+ KEY_USR_WRITE | KEY_USR_SEARCH),
+ KEY_ALLOC_NOT_IN_QUOTA, NULL);
+ if (!IS_ERR(keyring[id]))
+ set_bit(KEY_FLAG_TRUSTED_ONLY, &keyring[id]->flags);
+ else {
+ err = PTR_ERR(keyring[id]);
+ pr_info("Can't allocate %s keyring (%d)\n",
+ keyring_name[id], err);
+ keyring[id] = NULL;
+ }
+ return err;
+}
diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig
index 81a27971d884..08758fbd496f 100644
--- a/security/integrity/ima/Kconfig
+++ b/security/integrity/ima/Kconfig
@@ -123,3 +123,13 @@ config IMA_APPRAISE
For more information on integrity appraisal refer to:
<http://linux-ima.sourceforge.net>
If unsure, say N.
+
+config IMA_TRUSTED_KEYRING
+ bool "Require all keys on the .ima keyring be signed"
+ depends on IMA_APPRAISE && SYSTEM_TRUSTED_KEYRING
+ depends on INTEGRITY_ASYMMETRIC_KEYS
+ select KEYS_DEBUG_PROC_KEYS
+ default y
+ help
+ This option requires that all keys added to the .ima
+ keyring be signed by a key on the system trusted keyring.
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index f79fa8be203c..c42056edfc97 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -249,4 +249,16 @@ static inline int security_filter_rule_match(u32 secid, u32 field, u32 op,
return -EINVAL;
}
#endif /* CONFIG_IMA_LSM_RULES */
+
+#ifdef CONFIG_IMA_TRUSTED_KEYRING
+static inline int ima_init_keyring(const unsigned int id)
+{
+ return integrity_init_keyring(id);
+}
+#else
+static inline int ima_init_keyring(const unsigned int id)
+{
+ return 0;
+}
+#endif /* CONFIG_IMA_TRUSTED_KEYRING */
#endif
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index f474c608fa11..0d696431209c 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -325,8 +325,14 @@ static int __init init_ima(void)
hash_setup(CONFIG_IMA_DEFAULT_HASH);
error = ima_init();
- if (!error)
- ima_initialized = 1;
+ if (error)
+ goto out;
+
+ error = ima_init_keyring(INTEGRITY_KEYRING_IMA);
+ if (error)
+ goto out;
+ ima_initialized = 1;
+out:
return error;
}
diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
index 33c0a70f6b15..09c440d9aaee 100644
--- a/security/integrity/integrity.h
+++ b/security/integrity/integrity.h
@@ -124,6 +124,7 @@ struct integrity_iint_cache *integrity_iint_find(struct inode *inode);
int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
const char *digest, int digestlen);
+int integrity_init_keyring(const unsigned int id);
#else
static inline int integrity_digsig_verify(const unsigned int id,
@@ -133,6 +134,10 @@ static inline int integrity_digsig_verify(const unsigned int id,
return -EOPNOTSUPP;
}
+static inline int integrity_init_keyring(const unsigned int id)
+{
+ return 0;
+}
#endif /* CONFIG_INTEGRITY_SIGNATURE */
#ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS
--
cgit v1.2.2