From: Bryam Vargas <hexlabsecurity@proton.me>
commit 22b05fec62c0fe9864cfceb52f7d0f3a34d9b1dd upstream.
security_get_classes() sizes an array by p_classes.nprim and fills it at
value - 1, so a class value the policy never defines leaves a NULL.
sel_make_classes() passes every entry to sel_make_dir(), reaching the same
d_alloc_name() dereference as the permission array. The class symbol table
is allowed to be sparse (policydb_class_isvalid() exists to absorb that),
but this getter builds its own array straight from the hash table and has
no such predicate.
Fail the lookup when a value went unclaimed instead of handing out the
NULL. Conforming policies define every class they declare and are
unaffected.
Cc: stable@vger.kernel.org
Fixes: 55fcf09b3fe4 ("selinux: add support for querying object classes and permissions from the running policy")
Signed-off-by: Bryam Vargas <hexlabsecurity@proton.me>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Alexander Martyniuk <alexevgmart@gmail.com>
---
Backport fix for CVE-2026-80912
security/selinux/ss/services.c | 24 +++++++++++++++++++-----
1 file changed, 19 insertions(+), 5 deletions(-)
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index 80340bc0ee6a..a1e3520596d6 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -3414,6 +3414,7 @@ int security_get_classes(struct selinux_policy *policy,
char ***classes, u32 *nclasses)
{
struct policydb *policydb;
+ u32 i;
int rc;
policydb = &policy->policydb;
@@ -3426,16 +3427,29 @@ int security_get_classes(struct selinux_policy *policy,
rc = hashtab_map(&policydb->p_classes.table, get_classes_callback,
*classes);
- if (rc) {
- u32 i;
+ if (rc)
+ goto err;
- for (i = 0; i < *nclasses; i++)
- kfree((*classes)[i]);
- kfree(*classes);
+ /*
+ * The class symtab may be sparse, which policydb_class_isvalid() exists
+ * to absorb; the callback fills this array by value, so an unclaimed
+ * one leaves a NULL that sel_make_classes() hands to sel_make_dir().
+ */
+ for (i = 0; i < *nclasses; i++) {
+ if (!(*classes)[i]) {
+ rc = -EINVAL;
+ goto err;
+ }
}
out:
return rc;
+
+err:
+ for (i = 0; i < *nclasses; i++)
+ kfree((*classes)[i]);
+ kfree(*classes);
+ return rc;
}
static int get_permissions_callback(void *k, void *d, void *args)
--
2.43.0