From: Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx>
3.12-stable review patch. If anyone has any objections, please let me know.
===============
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@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Dr. Greg Wettstein <gw@xxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
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 4c3efe434806..84c6a9c1c531 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]
@@ -30,6 +30,7 @@ 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 085c4964be99..bab08da010ee 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 */
@@ -179,6 +180,16 @@ 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++) {
@@ -350,7 +361,8 @@ 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
};
@@ -371,6 +383,7 @@ 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"},
@@ -542,6 +555,9 @@ 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;
@@ -550,11 +566,14 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
result = strict_strtoul(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:
--
2.5.0
--
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