[PATCH 4.14 090/496] xfrm: do not call rcu_read_unlock when afinfo is NULL in xfrm_get_tos

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Xin Long <lucien.xin@xxxxxxxxx>

[ Upstream commit 143a4454daaf0e80a2b9f37159a0d6d2b61e64ed ]

When xfrm_policy_get_afinfo returns NULL, it will not hold rcu
read lock. In this case, rcu_read_unlock should not be called
in xfrm_get_tos, just like other places where it's calling
xfrm_policy_get_afinfo.

Fixes: f5e2bb4f5b22 ("xfrm: policy: xfrm_get_tos cannot fail")
Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx>
Signed-off-by: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 net/xfrm/xfrm_policy.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1459,10 +1459,13 @@ xfrm_tmpl_resolve(struct xfrm_policy **p
 static int xfrm_get_tos(const struct flowi *fl, int family)
 {
 	const struct xfrm_policy_afinfo *afinfo;
-	int tos = 0;
+	int tos;
 
 	afinfo = xfrm_policy_get_afinfo(family);
-	tos = afinfo ? afinfo->get_tos(fl) : 0;
+	if (!afinfo)
+		return 0;
+
+	tos = afinfo->get_tos(fl);
 
 	rcu_read_unlock();