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path: root/drivers/net/pptp.c
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Diffstat (limited to 'drivers/net/pptp.c')
-rw-r--r--drivers/net/pptp.c22
1 files changed, 14 insertions, 8 deletions
diff --git a/drivers/net/pptp.c b/drivers/net/pptp.c
index eae542a..89f829f 100644
--- a/drivers/net/pptp.c
+++ b/drivers/net/pptp.c
@@ -285,8 +285,10 @@ static int pptp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
ip_send_check(iph);
ip_local_out(skb);
+ return 1;
tx_error:
+ kfree_skb(skb);
return 1;
}
@@ -305,11 +307,18 @@ static int pptp_rcv_core(struct sock *sk, struct sk_buff *skb)
}
header = (struct pptp_gre_header *)(skb->data);
+ headersize = sizeof(*header);
/* test if acknowledgement present */
if (PPTP_GRE_IS_A(header->ver)) {
- __u32 ack = (PPTP_GRE_IS_S(header->flags)) ?
- header->ack : header->seq; /* ack in different place if S = 0 */
+ __u32 ack;
+
+ if (!pskb_may_pull(skb, headersize))
+ goto drop;
+ header = (struct pptp_gre_header *)(skb->data);
+
+ /* ack in different place if S = 0 */
+ ack = PPTP_GRE_IS_S(header->flags) ? header->ack : header->seq;
ack = ntohl(ack);
@@ -318,21 +327,18 @@ static int pptp_rcv_core(struct sock *sk, struct sk_buff *skb)
/* also handle sequence number wrap-around */
if (WRAPPED(ack, opt->ack_recv))
opt->ack_recv = ack;
+ } else {
+ headersize -= sizeof(header->ack);
}
-
/* test if payload present */
if (!PPTP_GRE_IS_S(header->flags))
goto drop;
- headersize = sizeof(*header);
payload_len = ntohs(header->payload_len);
seq = ntohl(header->seq);
- /* no ack present? */
- if (!PPTP_GRE_IS_A(header->ver))
- headersize -= sizeof(header->ack);
/* check for incomplete packet (length smaller than expected) */
- if (skb->len - headersize < payload_len)
+ if (!pskb_may_pull(skb, headersize + payload_len))
goto drop;
payload = skb->data + headersize;

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