From 08c239d8c05ca3212c3a4c431fead94e38f1953d Mon Sep 17 00:00:00 2001
From: Steffen Klassert <steffen.klassert@secunet.com>
Date: Thu, 1 Feb 2018 08:49:23 +0100
Subject: [PATCH 1/3] xfrm: Refuse to insert 32 bit userspace socket policies
on 64 bit systems
Git-commit: 19d7df69fdb2636856dc8919de72fc1bf8f79598
Patch-mainline: v4.16-rc7
References: git-fixes
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: Denis Kirjanov <denis.kirjanov@suse.com>
---
net/xfrm/xfrm_state.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index fd931648ff20..c9492e07a967 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -2034,6 +2034,11 @@ int xfrm_user_policy(struct sock *sk, int optname, u8 __user *optval, int optlen
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);
--
2.16.4