net: hdlc_fr: Do skb_reset_mac_header for skbs received on normal PVC devices
authorXie He <xie.he.0141@gmail.com>
Sat, 31 Oct 2020 18:10:41 +0000 (11:10 -0700)
committerJakub Kicinski <kuba@kernel.org>
Tue, 3 Nov 2020 23:19:09 +0000 (15:19 -0800)
When an skb is received on a normal (non-Ethernet-emulating) PVC device,
call skb_reset_mac_header before we pass it to upper layers.

This is because normal PVC devices don't have header_ops, so any header we
have would not be visible to upper layer code when sending, so the header
shouldn't be visible to upper layer code when receiving, either.

Cc: Krzysztof Halasa <khc@pm.waw.pl>
Cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Signed-off-by: Xie He <xie.he.0141@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
drivers/net/wan/hdlc_fr.c

index 71ee9b6..eb83116 100644 (file)
@@ -935,6 +935,7 @@ static int fr_rx(struct sk_buff *skb)
                skb_pull(skb, 4); /* Remove 4-byte header (hdr, UI, NLPID) */
                skb->dev = pvc->main;
                skb->protocol = htons(ETH_P_IP);
+               skb_reset_mac_header(skb);
 
        } else if (data[3] == NLPID_IPV6) {
                if (!pvc->main)
@@ -942,6 +943,7 @@ static int fr_rx(struct sk_buff *skb)
                skb_pull(skb, 4); /* Remove 4-byte header (hdr, UI, NLPID) */
                skb->dev = pvc->main;
                skb->protocol = htons(ETH_P_IPV6);
+               skb_reset_mac_header(skb);
 
        } else if (skb->len > 10 && data[3] == FR_PAD &&
                   data[4] == NLPID_SNAP && data[5] == FR_PAD) {
@@ -958,6 +960,7 @@ static int fr_rx(struct sk_buff *skb)
                                goto rx_drop;
                        skb->dev = pvc->main;
                        skb->protocol = htons(pid);
+                       skb_reset_mac_header(skb);
                        break;
 
                case 0x80C20007: /* bridged Ethernet frame */