[PATCH 4.9 044/105] net: skb_needs_check() accepts CHECKSUM_NONE for tx

From: Greg Kroah-Hartman
Date: Fri Aug 04 2017 - 20:08:41 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Eric Dumazet <edumazet@xxxxxxxxxx>

commit 6e7bc478c9a006c701c14476ec9d389a484b4864 upstream.

My recent change missed fact that UFO would perform a complete
UDP checksum before segmenting in frags.

In this case skb->ip_summed is set to CHECKSUM_NONE.

We need to add this valid case to skb_needs_check()

Fixes: b2504a5dbef3 ("net: reduce skb_warn_bad_offload() noise")
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Willem de Bruijn <willemb@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
net/core/dev.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2702,9 +2702,10 @@ EXPORT_SYMBOL(skb_mac_gso_segment);
static inline bool skb_needs_check(struct sk_buff *skb, bool tx_path)
{
if (tx_path)
- return skb->ip_summed != CHECKSUM_PARTIAL;
- else
- return skb->ip_summed == CHECKSUM_NONE;
+ return skb->ip_summed != CHECKSUM_PARTIAL &&
+ skb->ip_summed != CHECKSUM_NONE;
+
+ return skb->ip_summed == CHECKSUM_NONE;
}

/**