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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Matt Johnston <matt@codeconstruct.com.au>,
        "David S. Miller" <davem@davemloft.net>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.17 211/343] mctp: Fix check for dev_hard_header() result
Date:   Tue, 12 Apr 2022 08:30:29 +0200
Message-Id: <20220412062957.437294374@linuxfoundation.org>
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From: Matt Johnston <matt@codeconstruct.com.au>

[ 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>
---
 net/mctp/route.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/mctp/route.c b/net/mctp/route.c
index 05fbd318eb98..d47438f5233d 100644
--- a/net/mctp/route.c
+++ b/net/mctp/route.c
@@ -507,7 +507,7 @@ 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;
 	}
-- 
2.35.1