[PATCH 4.9 24/96] net: avoid use IPCB in cipso_v4_error

Greg Kroah-Hartman
2019-03-12T17:27:37Z

From: Nazarov Sergey <s-nazarov@yandex.ru>

[ Upstream commit 3da1ed7ac398f34fff1694017a07054d69c5f5c5 ]

Extract IP options in cipso_v4_error and use __icmp_send.

Signed-off-by: Sergey Nazarov <s-nazarov@yandex.ru>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
include/net/ip.h | 2 ++
net/ipv4/cipso_ipv4.c | 17 +++++++++++++++--
net/ipv4/ip_options.c | 22 +++++++++++++++++-----
3 files changed, 34 insertions(+), 7 deletions(-)

--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -570,6 +570,8 @@ static inline int ip_options_echo(struct
}

void ip_options_fragment(struct sk_buff *skb);
+int __ip_options_compile(struct net *net, struct ip_options *opt,
+ struct sk_buff *skb, __be32 *info);
int ip_options_compile(struct net *net, struct ip_options *opt,
struct sk_buff *skb);
int ip_options_get(struct net *net, struct ip_options_rcu **optp,
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -1736,13 +1736,26 @@ validate_return:
*/
void cipso_v4_error(struct sk_buff *skb, int error, u32 gateway)
{
+ unsigned char optbuf[sizeof(struct ip_options) + 40];
+ struct ip_options *opt = (struct ip_options *)optbuf;
+
if (ip_hdr(skb)->protocol == IPPROTO_ICMP || error != -EACCES)
return;

+ /*
+ * We might be called above the IP layer,
+ * so we can not use icmp_send and IPCB here.
+ */
+
+ memset(opt, 0, sizeof(struct ip_options));
+ opt->optlen = ip_hdr(skb)->ihl*4 - sizeof(struct iphdr);
+ if (__ip_options_compile(dev_net(skb->dev), opt, skb, NULL))
+ return;
+
if (gateway)
- icmp_send(skb, ICMP_DEST_UNREACH, ICMP_NET_ANO, 0);
+ __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_NET_ANO, 0, opt);
else
- icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_ANO, 0);
+ __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_ANO, 0, opt);
}

/**
--- a/net/ipv4/ip_options.c
+++ b/net/ipv4/ip_options.c
@@ -253,8 +253,9 @@ static void spec_dst_fill(__be32 *spec_d
* If opt == NULL, then skb->data should point to IP header.
*/

-int ip_options_compile(struct net *net,
- struct ip_options *opt, struct sk_buff *skb)
+int __ip_options_compile(struct net *net,
+ struct ip_options *opt, struct sk_buff *skb,
+ __be32 *info)
{
__be32 spec_dst = htonl(INADDR_ANY);
unsigned char *pp_ptr = NULL;
@@ -470,11 +471,22 @@ eol:
return 0;

error:
- if (skb) {
- icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl((pp_ptr-iph)<<24));
- }
+ if (info)
+ *info = htonl((pp_ptr-iph)<<24);
return -EINVAL;
}
+
+int ip_options_compile(struct net *net,
+ struct ip_options *opt, struct sk_buff *skb)
+{
+ int ret;
+ __be32 info;
+
+ ret = __ip_options_compile(net, opt, skb, &info);
+ if (ret != 0 && skb)
+ icmp_send(skb, ICMP_PARAMETERPROB, 0, info);
+ return ret;
+}
EXPORT_SYMBOL(ip_options_compile);

/*