xfrm: Refuse to insert 32 bit userspace socket policies on 64 bit systems
commit 19d7df69fdb2636856dc8919de72fc1bf8f79598 upstream.
We don't have a compat layer for xfrm, so userspace and kernel
structures have different sizes in this case. This results in
a broken configuration, so refuse to configure socket policies
when trying to insert from 32 bit userspace as we do it already
with policies inserted via netlink.
Reported-and-tested-by: syzbot+e1a1577ca8bcb47b769a@syzkaller.appspotmail.com
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 13e0611..fdb9742 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -1883,6 +1883,11 @@
struct xfrm_mgr *km;
struct xfrm_policy *pol = NULL;
+#ifdef CONFIG_COMPAT
+ if (in_compat_syscall())
+ return -EOPNOTSUPP;
+#endif
+
if (!optval && !optlen) {
xfrm_sk_policy_insert(sk, XFRM_POLICY_IN, NULL);
xfrm_sk_policy_insert(sk, XFRM_POLICY_OUT, NULL);