diff mbox series

[06/11,v2] libsepol/cil: More strict verification of constraint leaf expressions

Message ID 20210419151557.87561-7-jwcart2@gmail.com (mailing list archive)
State Accepted
Headers show
Series Various CIL patches | expand

Commit Message

James Carter April 19, 2021, 3:15 p.m. UTC 
In constraint expressions u1, u3, r1, r3, t1, and t3 are never
allowed on the right side of an expression, but there were no checks
to verify that they were not used on the right side. The result was
that the expression "(eq t1 t1)" would be silently turned into
"(eq t1 t2)" when the binary policy was created.

Verify that u1, u3, r1, r3, t1, and t3 are not used on the right
side of a constraint expression.

Signed-off-by: James Carter <jwcart2@gmail.com>
---
 libsepol/cil/src/cil_verify.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)
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Patch

diff --git a/libsepol/cil/src/cil_verify.c b/libsepol/cil/src/cil_verify.c
index 09e3daf9..2707b6c9 100644
--- a/libsepol/cil/src/cil_verify.c
+++ b/libsepol/cil/src/cil_verify.c
@@ -227,7 +227,13 @@  int cil_verify_constraint_leaf_expr_syntax(enum cil_flavor l_flavor, enum cil_fl
 			}
 		}
 	} else {
-		if (r_flavor == CIL_CONS_U2) {
+		if (r_flavor == CIL_CONS_U1 || r_flavor == CIL_CONS_R1 || r_flavor == CIL_CONS_T1) {
+			cil_log(CIL_ERR, "u1, r1, and t1 are not allowed on the right side\n");
+			goto exit;
+		} else if (r_flavor == CIL_CONS_U3 || r_flavor == CIL_CONS_R3 || r_flavor == CIL_CONS_T3) {
+			cil_log(CIL_ERR, "u3, r3, and t3 are not allowed on the right side\n");
+			goto exit;
+		} else if (r_flavor == CIL_CONS_U2) {
 			if (op != CIL_EQ && op != CIL_NEQ) {
 				cil_log(CIL_ERR, "u2 on the right side must be used with eq or neq as the operator\n");
 				goto exit;