[XFRM] xfrm_user: Better validation of user templates.
Since we never checked the ->family value of templates
before, many applications simply leave it at zero.
Detect this and fix it up to be the pol->family value.
Also, do not clobber xp->family while reading in templates,
that is not necessary.
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 6f97665..311205f 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -858,7 +858,6 @@
int i;
xp->xfrm_nr = nr;
- xp->family = ut->family;
for (i = 0; i < nr; i++, ut++) {
struct xfrm_tmpl *t = &xp->xfrm_vec[i];
@@ -876,19 +875,53 @@
}
}
+static int validate_tmpl(int nr, struct xfrm_user_tmpl *ut, u16 family)
+{
+ int i;
+
+ if (nr > XFRM_MAX_DEPTH)
+ return -EINVAL;
+
+ for (i = 0; i < nr; i++) {
+ /* We never validated the ut->family value, so many
+ * applications simply leave it at zero. The check was
+ * never made and ut->family was ignored because all
+ * templates could be assumed to have the same family as
+ * the policy itself. Now that we will have ipv4-in-ipv6
+ * and ipv6-in-ipv4 tunnels, this is no longer true.
+ */
+ if (!ut[i].family)
+ ut[i].family = family;
+
+ switch (ut[i].family) {
+ case AF_INET:
+ break;
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+ case AF_INET6:
+ break;
+#endif
+ default:
+ return -EINVAL;
+ };
+ }
+
+ return 0;
+}
+
static int copy_from_user_tmpl(struct xfrm_policy *pol, struct rtattr **xfrma)
{
struct rtattr *rt = xfrma[XFRMA_TMPL-1];
- struct xfrm_user_tmpl *utmpl;
- int nr;
if (!rt) {
pol->xfrm_nr = 0;
} else {
- nr = (rt->rta_len - sizeof(*rt)) / sizeof(*utmpl);
+ struct xfrm_user_tmpl *utmpl = RTA_DATA(rt);
+ int nr = (rt->rta_len - sizeof(*rt)) / sizeof(*utmpl);
+ int err;
- if (nr > XFRM_MAX_DEPTH)
- return -EINVAL;
+ err = validate_tmpl(nr, utmpl, pol->family);
+ if (err)
+ return err;
copy_templates(pol, RTA_DATA(rt), nr);
}
@@ -1530,7 +1563,8 @@
}
/* build an XP */
- xp = xfrm_policy_construct(&ua->policy, (struct rtattr **) xfrma, &err); if (!xp) {
+ xp = xfrm_policy_construct(&ua->policy, (struct rtattr **) xfrma, &err);
+ if (!xp) {
kfree(x);
return err;
}
@@ -1979,7 +2013,7 @@
return NULL;
nr = ((len - sizeof(*p)) / sizeof(*ut));
- if (nr > XFRM_MAX_DEPTH)
+ if (validate_tmpl(nr, ut, p->sel.family))
return NULL;
if (p->dir > XFRM_POLICY_OUT)