From: Xin Long <lucien.xin@gmail.com>
Subject: xfrm: do not call rcu_read_unlock when afinfo is NULL
 in xfrm_get_tos
Patch-mainline: v4.16-rc7
Git-commit: 143a4454daaf0e80a2b9f37159a0d6d2b61e64ed
References: git-fixes

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@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Denis Kirjanov <dkirjanov@suse.com>
---
 net/xfrm/xfrm_policy.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 2f16ab3ecc88..70ed1f452941 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1536,10 +1536,13 @@ xfrm_tmpl_resolve(struct xfrm_policy **pols, int npols, const struct flowi *fl,
 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();
 
-- 
2.12.3