audit: validate comparison operations, store them in sane form

PATCH In review Al Viro 2 participants 2 messages Dec 17, 2008

Subsystems (4)

SELinux security module Security (LSM) Audit Smack security module

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Al Viro

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2008-12-17 05:14 UTC #0 lore raw

PATCH 15/15 audit: validate comparison operations, store them in sane form

Don't store the field->op in the messy (and very inconvenient for e.g. audit_comparator()) form; translate to dense set of values and do full validation of userland-submitted value while we are at it.

->audit_init_rule() and ->audit_match_rule() get new values now; in-tree instances updated.

Signed-off-by Al Viro <[email protected]>

---
 include/linux/audit.h          |   12 ++++
 kernel/audit_tree.c            |    2 +-
 kernel/auditfilter.c           |  132 ++++++++++++++++++++--------------------
 security/selinux/ss/services.c |   26 ++++----
 security/smack/smack_lsm.c     |    6 +-
 5 files changed, 94 insertions(+), 84 deletions(-)

include/linux/audit.h +12 -0

index 4e37f06..1f73f5e 100644
@@ -245,6 +245,18 @@
 #define AUDIT_GREATER_THAN_OR_EQUAL	(AUDIT_GREATER_THAN|AUDIT_EQUAL)
 #define AUDIT_OPERATORS			(AUDIT_EQUAL|AUDIT_NOT_EQUAL|AUDIT_BIT_MASK)
 
+enum {
+	Audit_equal,
+	Audit_not_equal,
+	Audit_bitmask,
+	Audit_bittest,
+	Audit_lt,
+	Audit_gt,
+	Audit_le,
+	Audit_ge,
+	Audit_bad
+};
+
 /* Status symbols */
 				/* Mask values */
 #define AUDIT_STATUS_ENABLED		0x0001

kernel/audit_tree.c +1 -1

index 48bddad..8ad9545 100644
@@ -618,7 +618,7 @@ int audit_make_tree(struct audit_krule *rule, char *pathname, u32 op)
 
 	if (pathname[0] != '/' ||
 	    rule->listnr != AUDIT_FILTER_EXIT ||
-	    op & ~AUDIT_EQUAL ||
+	    op != Audit_equal ||
 	    rule->inode_f || rule->watch || rule->tree)
 		return -EINVAL;
 	rule->tree = alloc_tree(pathname);

kernel/auditfilter.c +65 ~~-67~~

239 lines not on this page · raw message

security/selinux/ss/services.c +13 ~~-13~~

index 343c8ab..c65e4fe 100644
@@ -2602,7 +2602,7 @@ int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
 	case AUDIT_OBJ_ROLE:
 	case AUDIT_OBJ_TYPE:
 		/* only 'equals' and 'not equals' fit user, role, and type */
-		if (op != AUDIT_EQUAL && op != AUDIT_NOT_EQUAL)
+		if (op != Audit_equal && op != Audit_not_equal)
 			return -EINVAL;
 		break;
 	case AUDIT_SUBJ_SEN:

@@ -2736,10 +2736,10 @@ int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
 	case AUDIT_SUBJ_USER:
 	case AUDIT_OBJ_USER:
 		switch (op) {
-		case AUDIT_EQUAL:
+		case Audit_equal:
 			match = (ctxt->user == rule->au_ctxt.user);
 			break;
-		case AUDIT_NOT_EQUAL:
+		case Audit_not_equal:
 			match = (ctxt->user != rule->au_ctxt.user);
 			break;
 		}

@@ -2747,10 +2747,10 @@ int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
 	case AUDIT_SUBJ_ROLE:
 	case AUDIT_OBJ_ROLE:
 		switch (op) {
-		case AUDIT_EQUAL:
+		case Audit_equal:
 			match = (ctxt->role == rule->au_ctxt.role);
 			break;
-		case AUDIT_NOT_EQUAL:
+		case Audit_not_equal:
 			match = (ctxt->role != rule->au_ctxt.role);
 			break;
 		}

@@ -2758,10 +2758,10 @@ int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
 	case AUDIT_SUBJ_TYPE:
 	case AUDIT_OBJ_TYPE:
 		switch (op) {
-		case AUDIT_EQUAL:
+		case Audit_equal:
 			match = (ctxt->type == rule->au_ctxt.type);
 			break;
-		case AUDIT_NOT_EQUAL:
+		case Audit_not_equal:
 			match = (ctxt->type != rule->au_ctxt.type);
 			break;
 		}

@@ -2774,31 +2774,31 @@ int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
 			  field == AUDIT_OBJ_LEV_LOW) ?
 			 &ctxt->range.level[0] : &ctxt->range.level[1]);
 		switch (op) {
-		case AUDIT_EQUAL:
+		case Audit_equal:
 			match = mls_level_eq(&rule->au_ctxt.range.level[0],
 					     level);
 			break;
-		case AUDIT_NOT_EQUAL:
+		case Audit_not_equal:
 			match = !mls_level_eq(&rule->au_ctxt.range.level[0],
 					      level);
 			break;
-		case AUDIT_LESS_THAN:
+		case Audit_lt:
 			match = (mls_level_dom(&rule->au_ctxt.range.level[0],
 					       level) &&
 				 !mls_level_eq(&rule->au_ctxt.range.level[0],
 					       level));
 			break;
-		case AUDIT_LESS_THAN_OR_EQUAL:
+		case Audit_le:
 			match = mls_level_dom(&rule->au_ctxt.range.level[0],
 					      level);
 			break;
-		case AUDIT_GREATER_THAN:
+		case Audit_gt:
 			match = (mls_level_dom(level,
 					      &rule->au_ctxt.range.level[0]) &&
 				 !mls_level_eq(level,
 					       &rule->au_ctxt.range.level[0]));
 			break;
-		case AUDIT_GREATER_THAN_OR_EQUAL:
+		case Audit_ge:
 			match = mls_level_dom(level,
 					      &rule->au_ctxt.range.level[0]);
 			break;

security/smack/smack_lsm.c +3 -3

index 6e2dc0b..45eacc4 100644
@@ -2443,7 +2443,7 @@ static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
 	if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
 		return -EINVAL;
 
-	if (op != AUDIT_EQUAL && op != AUDIT_NOT_EQUAL)
+	if (op != Audit_equal && op != Audit_not_equal)
 		return -EINVAL;
 
 	*rule = smk_import(rulestr, 0);

@@ -2507,9 +2507,9 @@ static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule,
 	 * both pointers will point to the same smack_known
 	 * label.
 	 */
-	if (op == AUDIT_EQUAL)
+	if (op == Audit_equal)
 		return (rule == smack);
-	if (op == AUDIT_NOT_EQUAL)
+	if (op == Audit_not_equal)
 		return (rule != smack);
 
 	return 0;

Signature · 1 line

1.5.6.5

James Morris

maintainer Reviewed-by on v1 15/15

2008-12-17 07:54 UTC #1 lore raw

Quoted 9 lines · Al Viro

Don't store the field->op in the messy (and very inconvenient for e.g. audit_comparator()) form; translate to dense set of values and do full validation of userland-submitted value while we are at it.
->audit_init_rule() and ->audit_match_rule() get new values now; in-tree instances updated.
Signed-off-by Al Viro <[email protected]>

Reviewed-by James Morris <[email protected]>

Signature · 2 lines

James Morris
<[email protected]>