[PATCH 4.19 078/105] packet: do not set TP_STATUS_CSUM_VALID on CHECKSUM_COMPLETE

Greg Kroah-Hartman
2022-12-05T19:21:16Z

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

[ Upstream commit b85f628aa158a653c006e9c1405a117baef8c868 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 f654f79e3310..6fa0a9a453a8 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -2209,8 +2209,7 @@ 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)
@@ -3452,8 +3451,7 @@ 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;
--
2.35.1