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authorJiri Benc <jbenc@redhat.com>2016-04-29 23:31:32 +0200
committerDavid S. Miller <davem@davemloft.net>2016-05-02 00:19:58 -0400
commitb7f8fe251e4609e2a437bd2c2dea01e61db6849c (patch)
tree2c1fec745c1ddb827e787b68e16b8ca987874aeb /net
parent2c94b53738549d81dc7464a32117d1f5112c64d3 (diff)
gre: do not pull header in ICMP error processing
iptunnel_pull_header expects that IP header was already pulled; with this expectation, it pulls the tunnel header. This is not true in gre_err. Furthermore, ipv4_update_pmtu and ipv4_redirect expect that skb->data points to the IP header. We cannot pull the tunnel header in this path. It's just a matter of not calling iptunnel_pull_header - we don't need any of its effects. Fixes: bda7bb463436 ("gre: Allow multiple protocol listener for gre protocol.") Signed-off-by: Jiri Benc <jbenc@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/ip_gre.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index f502d34bcb40..205a2b8a5a84 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -179,6 +179,7 @@ static __be16 tnl_flags_to_gre_flags(__be16 tflags)
return flags;
}
+/* Fills in tpi and returns header length to be pulled. */
static int parse_gre_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,
bool *csum_err)
{
@@ -238,7 +239,7 @@ static int parse_gre_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,
return -EINVAL;
}
}
- return iptunnel_pull_header(skb, hdr_len, tpi->proto, false);
+ return hdr_len;
}
static void ipgre_err(struct sk_buff *skb, u32 info,
@@ -341,7 +342,7 @@ static void gre_err(struct sk_buff *skb, u32 info)
struct tnl_ptk_info tpi;
bool csum_err = false;
- if (parse_gre_header(skb, &tpi, &csum_err)) {
+ if (parse_gre_header(skb, &tpi, &csum_err) < 0) {
if (!csum_err) /* ignore csum errors. */
return;
}
@@ -419,6 +420,7 @@ static int gre_rcv(struct sk_buff *skb)
{
struct tnl_ptk_info tpi;
bool csum_err = false;
+ int hdr_len;
#ifdef CONFIG_NET_IPGRE_BROADCAST
if (ipv4_is_multicast(ip_hdr(skb)->daddr)) {
@@ -428,7 +430,10 @@ static int gre_rcv(struct sk_buff *skb)
}
#endif
- if (parse_gre_header(skb, &tpi, &csum_err) < 0)
+ hdr_len = parse_gre_header(skb, &tpi, &csum_err);
+ if (hdr_len < 0)
+ goto drop;
+ if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false) < 0)
goto drop;
if (ipgre_rcv(skb, &tpi) == PACKET_RCVD)