From: Simon Horman <horms@verge.net.au>
Date: Tue, 28 May 2013 20:34:23 +0000 (+0000)
Subject: isdn: Correct comparison of skb->tail and skb-transport_header
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=25b6e14881e7861bb720a4624dcaf5f37854fc70;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git

isdn: Correct comparison of skb->tail and skb-transport_header

This corrects an regression introduced by "net: Use 16bits for *_headers
fields of struct skbuff" when NET_SKBUFF_DATA_USES_OFFSET is not set. In
that case skb->tail will be a pointer whereas skb->transport_header
will be an offset from head. This is corrected by using wrappers that
ensure that the comparison is always between pointers.

Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/isdn/i4l/isdn_net.c b/drivers/isdn/i4l/isdn_net.c
index 88d657dff474..8b98d53d9976 100644
--- a/drivers/isdn/i4l/isdn_net.c
+++ b/drivers/isdn/i4l/isdn_net.c
@@ -885,7 +885,7 @@ isdn_net_log_skb(struct sk_buff *skb, isdn_net_local *lp)
 
 	addinfo[0] = '\0';
 	/* This check stolen from 2.1.72 dev_queue_xmit_nit() */
-	if (p < skb->data || skb->network_header >= skb->tail) {
+	if (p < skb->data || skb_network_header(skb) >= skb_tail_pointer(skb)) {
 		/* fall back to old isdn_net_log_packet method() */
 		char *buf = skb->data;