[PATCH AUTOSEL 4.19 16/97] xfrm: Fix error return code in xfrm_output_one()

[Sasha Levin]

From: Wei Yongjun <weiyongjun1@xxxxxxxxxx>

[ Upstream commit 533555e5cbb6aa2d77598917871ae5b579fe724b ]

xfrm_output_one() does not return a error code when there is
no dst_entry attached to the skb, it is still possible crash
with a NULL pointer dereference in xfrm_output_resume(). Fix
it by return error code -EHOSTUNREACH.

Fixes: 9e1437937807 ("xfrm: Fix NULL pointer dereference when skb_dst_force clears the dst_entry.")
Signed-off-by: Wei Yongjun <weiyongjun1@xxxxxxxxxx>
Signed-off-by: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 net/xfrm/xfrm_output.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c
index 261995d37ced..6d20fbcde000 100644
--- a/net/xfrm/xfrm_output.c
+++ b/net/xfrm/xfrm_output.c
@@ -102,6 +102,7 @@ static int xfrm_output_one(struct sk_buff *skb, int err)
 		skb_dst_force(skb);
 		if (!skb_dst(skb)) {
 			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
+			err = -EHOSTUNREACH;
 			goto error_nolock;
 		}
 
-- 
2.19.1