netdev - [PATCH net] packet: do not set TP_STATUS_CSUM_VALID on CHECKSUM

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Message-Id: <20221128161812.640098-1-willemdebruijn.kernel@gmail.com>
Date:   Mon, 28 Nov 2022 11:18:12 -0500
From:   Willem de Bruijn <willemdebruijn.kernel@...il.com>
To:     netdev@...r.kernel.org
Cc:     davem@...emloft.net, kuba@...nel.org, edumazet@...gle.com,
        pabeni@...hat.com, al.drozdov@...il.com, alexanderduyck@...com,
        Willem de Bruijn <willemb@...gle.com>
Subject: [PATCH net] packet: do not set TP_STATUS_CSUM_VALID on CHECKSUM_COMPLETE

From: Willem de Bruijn <willemb@...gle.com>

CHECKSUM_COMPLETE signals that skb->csum stores the sum over the
entire packet. It does not imply that an embedded l4 checksum
field has been validated.

Fixes: 682f048bd494 ("af_packet: pass checksum validation status to the user")
Signed-off-by: Willem de Bruijn <willemb@...gle.com>
---
 net/packet/af_packet.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 6ce8dd19f33c..1ab65f7f2a0a 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -2293,8 +2293,7 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
 	if (skb->ip_summed == CHECKSUM_PARTIAL)
 		status |= TP_STATUS_CSUMNOTREADY;
 	else if (skb->pkt_type != PACKET_OUTGOING &&
-		 (skb->ip_summed == CHECKSUM_COMPLETE ||
-		  skb_csum_unnecessary(skb)))
+		 skb_csum_unnecessary(skb))
 		status |= TP_STATUS_CSUM_VALID;
 
 	if (snaplen > res)
@@ -3520,8 +3519,7 @@ static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
 		if (skb->ip_summed == CHECKSUM_PARTIAL)
 			aux.tp_status |= TP_STATUS_CSUMNOTREADY;
 		else if (skb->pkt_type != PACKET_OUTGOING &&
-			 (skb->ip_summed == CHECKSUM_COMPLETE ||
-			  skb_csum_unnecessary(skb)))
+			 skb_csum_unnecessary(skb))
 			aux.tp_status |= TP_STATUS_CSUM_VALID;
 
 		aux.tp_len = origlen;
-- 
2.38.1.584.g0f3c55d4c2-goog