From: Bryam Vargas Date: Fri, 31 Jul 2026 17:44:12 +0000 (-0500) Subject: selinux: require every boolean value to be defined X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=a93d37a09b863810653f93d371fb197457d59deb;p=thirdparty%2Fkernel%2Flinux.git selinux: require every boolean value to be defined p_bools.nprim comes from the policy image independently of how many booleans follow it, and cond_index_bool() fills bool_val_to_struct[] at value - 1, so a count larger than the values present leaves NULL entries. Every user of that array then walks it by index and dereferences each entry: cond_evaluate_expr() on the access-vector path, security_get_bools() and security_get_bool_value() behind selinuxfs, and security_set_bools(). A sparse class value is absorbed by policydb_class_isvalid() and its siblings; booleans have no such predicate, and no consumer that could use one. Reject a boolean value that no boolean defines, once, where the array is built. Conforming policies define every boolean they declare and are unaffected. Cc: stable@vger.kernel.org Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Bryam Vargas Acked-by: Stephen Smalley Signed-off-by: Paul Moore --- diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c index d358200817bd..d88713201be9 100644 --- a/security/selinux/ss/policydb.c +++ b/security/selinux/ss/policydb.c @@ -719,6 +719,7 @@ static inline void symtab_hash_eval(struct symtab *s) static int policydb_index(struct policydb *p) { int i, rc; + u32 v; if (p->mls_enabled) pr_debug( @@ -769,6 +770,24 @@ static int policydb_index(struct policydb *p) if (rc) goto out; } + + /* + * A sparse class value is absorbed by policydb_class_isvalid() and + * its siblings, but no such predicate exists for booleans: every + * user of bool_val_to_struct[] walks it by index and dereferences + * each entry -- cond_evaluate_expr(), the two getters and + * security_set_bools() -- so an unclaimed one has no consumer that + * can tolerate it. + */ + for (v = 0; v < p->p_bools.nprim; v++) { + if (!p->bool_val_to_struct[v]) { + pr_err("SELinux: boolean %u is declared but not defined\n", + v + 1); + rc = -EINVAL; + goto out; + } + } + rc = 0; out: return rc;