packet: do not set TP_STATUS_CSUM_VALID on CHECKSUM_COMPLETE

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@google.com>
Link: https://lore.kernel.org/r/20221128161812.640098-1-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 6ce8dd1..1ab65f7 100644 (file)
--- 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;