mctp: Fix check for dev_hard_header() result

[ Upstream commit 60be976ac45137657b7b505d7e0d44d0e51accb7 ]

dev_hard_header() returns the length of the header, so
we need to test for negative errors rather than non-zero.

Fixes: 889b7da23abf ("mctp: Add initial routing framework")
Signed-off-by: Matt Johnston <matt@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/mctp/route.c b/net/mctp/route.c
index fb1bf4e..bbb13db 100644 (file)
--- a/net/mctp/route.c
+++ b/net/mctp/route.c
@@ -396,7 +396,7 @@ static int mctp_route_output(struct mctp_route *route, struct sk_buff *skb)
 
        rc = dev_hard_header(skb, skb->dev, ntohs(skb->protocol),
                             daddr, skb->dev->dev_addr, skb->len);
-       if (rc) {
+       if (rc < 0) {
                kfree_skb(skb);
                return -EHOSTUNREACH;
        }