linux-kernel - [PATCH 3.19.y-ckt 120/251] ima: add support for new "euid" policy condition

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1437008972-9140-121-git-send-email-kamal@canonical.com>
Date:	Wed, 15 Jul 2015 18:07:21 -0700
From:	Kamal Mostafa <kamal@...onical.com>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org,
	kernel-team@...ts.ubuntu.com
Cc:	Mimi Zohar <zohar@...ux.vnet.ibm.com>,
	"Dr. Greg Wettstein" <gw@...usion.org>,
	Kamal Mostafa <kamal@...onical.com>
Subject: [PATCH 3.19.y-ckt 120/251] ima: add support for new "euid" policy condition

3.19.8-ckt4 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Mimi Zohar <zohar@...ux.vnet.ibm.com>

commit 139069eff7388407f19794384c42a534d618ccd7 upstream.

The new "euid" policy condition measures files with the specified
effective uid (euid).  In addition, for CAP_SETUID files it measures
files with the specified uid or suid.

Changelog:
- fixed checkpatch.pl warnings
- fixed avc denied {setuid} messages - based on Roberto's feedback

Signed-off-by: Mimi Zohar <zohar@...ux.vnet.ibm.com>
Signed-off-by: Dr. Greg Wettstein <gw@...usion.org>
Signed-off-by: Kamal Mostafa <kamal@...onical.com>
---
 Documentation/ABI/testing/ima_policy |  3 ++-
 security/integrity/ima/ima_policy.c  | 27 +++++++++++++++++++++++----
 2 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy
index 8ae3f57..4a571fa 100644
--- a/Documentation/ABI/testing/ima_policy
+++ b/Documentation/ABI/testing/ima_policy
@@ -20,7 +20,7 @@ Description:
 		action: measure | dont_measure | appraise | dont_appraise | audit
 		condition:= base | lsm  [option]
 			base:	[[func=] [mask=] [fsmagic=] [fsuuid=] [uid=]
-				 [fowner]]
+				[euid=] [fowner=]]
 			lsm:	[[subj_user=] [subj_role=] [subj_type=]
 				 [obj_user=] [obj_role=] [obj_type=]]
 			option:	[[appraise_type=]] [permit_directio]
@@ -31,6 +31,7 @@ Description:
 			fsmagic:= hex value
 			fsuuid:= file system UUID (e.g 8bcbe394-4f13-4144-be8e-5aa9ea2ce2f6)
 			uid:= decimal value
+			euid:= decimal value
 			fowner:=decimal value
 		lsm:  	are LSM specific
 		option:	appraise_type:= [imasig]
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index e1f73f8..d0f4c92 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -27,6 +27,7 @@
 #define IMA_UID		0x0008
 #define IMA_FOWNER	0x0010
 #define IMA_FSUUID	0x0020
+#define IMA_EUID	0x0080
 
 #define UNKNOWN		0
 #define MEASURE		0x0001	/* same as IMA_MEASURE */
@@ -194,6 +195,16 @@ static bool ima_match_rules(struct ima_rule_entry *rule,
 		return false;
 	if ((rule->flags & IMA_UID) && !uid_eq(rule->uid, cred->uid))
 		return false;
+	if (rule->flags & IMA_EUID) {
+		if (has_capability_noaudit(current, CAP_SETUID)) {
+			if (!uid_eq(rule->uid, cred->euid)
+			    && !uid_eq(rule->uid, cred->suid)
+			    && !uid_eq(rule->uid, cred->uid))
+				return false;
+		} else if (!uid_eq(rule->uid, cred->euid))
+			return false;
+	}
+
 	if ((rule->flags & IMA_FOWNER) && !uid_eq(rule->fowner, inode->i_uid))
 		return false;
 	for (i = 0; i < MAX_LSM_RULES; i++) {
@@ -377,7 +388,8 @@ enum {
 	Opt_audit,
 	Opt_obj_user, Opt_obj_role, Opt_obj_type,
 	Opt_subj_user, Opt_subj_role, Opt_subj_type,
-	Opt_func, Opt_mask, Opt_fsmagic, Opt_uid, Opt_fowner,
+	Opt_func, Opt_mask, Opt_fsmagic,
+	Opt_uid, Opt_euid, Opt_fowner,
 	Opt_appraise_type, Opt_fsuuid, Opt_permit_directio
 };
 
@@ -398,6 +410,7 @@ static match_table_t policy_tokens = {
 	{Opt_fsmagic, "fsmagic=%s"},
 	{Opt_fsuuid, "fsuuid=%s"},
 	{Opt_uid, "uid=%s"},
+	{Opt_euid, "euid=%s"},
 	{Opt_fowner, "fowner=%s"},
 	{Opt_appraise_type, "appraise_type=%s"},
 	{Opt_permit_directio, "permit_directio"},
@@ -570,6 +583,9 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 			break;
 		case Opt_uid:
 			ima_log_string(ab, "uid", args[0].from);
+		case Opt_euid:
+			if (token == Opt_euid)
+				ima_log_string(ab, "euid", args[0].from);
 
 			if (uid_valid(entry->uid)) {
 				result = -EINVAL;
@@ -578,11 +594,14 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 
 			result = kstrtoul(args[0].from, 10, &lnum);
 			if (!result) {
-				entry->uid = make_kuid(current_user_ns(), (uid_t)lnum);
-				if (!uid_valid(entry->uid) || (((uid_t)lnum) != lnum))
+				entry->uid = make_kuid(current_user_ns(),
+						       (uid_t) lnum);
+				if (!uid_valid(entry->uid) ||
+				    (uid_t)lnum != lnum)
 					result = -EINVAL;
 				else
-					entry->flags |= IMA_UID;
+					entry->flags |= (token == Opt_uid)
+					    ? IMA_UID : IMA_EUID;
 			}
 			break;
 		case Opt_fowner:
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/