| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <1452246774-13241-17-git-send-email-huw@codeweavers.com>
Date: Fri, 8 Jan 2016 09:52:52 +0000
From: Huw Davies <huw@...eweavers.com>
To: netdev@...r.kernel.org, linux-security-module@...r.kernel.org,
selinux@...ho.nsa.gov
Cc: Paul Moore <pmoore@...hat.com>
Subject: [RFC PATCH v2 16/18] calipso: Add validation of CALIPSO option.
We check lengths, checksum and the DOI. We leave checking of the
level and categories for the socket layer.
Signed-off-by: Huw Davies <huw@...eweavers.com>
---
include/net/calipso.h | 6 ++++++
net/ipv6/calipso.c | 43 +++++++++++++++++++++++++++++++++++++++++++
net/ipv6/exthdrs.c | 27 +++++++++++++++++++++++++++
3 files changed, 76 insertions(+)
diff --git a/include/net/calipso.h b/include/net/calipso.h
index ad4d653..99df89b 100644
--- a/include/net/calipso.h
+++ b/include/net/calipso.h
@@ -65,6 +65,7 @@ struct calipso_doi {
#ifdef CONFIG_NETLABEL
int __init calipso_init(void);
void calipso_exit(void);
+bool calipso_validate(const struct sk_buff *skb, const unsigned char *option);
#else
static inline int __init calipso_init(void)
{
@@ -74,6 +75,11 @@ static inline int __init calipso_init(void)
static inline void calipso_exit(void)
{
}
+static inline bool calipso_validate(const struct sk_buff *skb,
+ const unsigned char *option)
+{
+ return true;
+}
#endif /* CONFIG_NETLABEL */
#endif /* _CALIPSO_H */
diff --git a/net/ipv6/calipso.c b/net/ipv6/calipso.c
index 1616464..4aa2f66 100644
--- a/net/ipv6/calipso.c
+++ b/net/ipv6/calipso.c
@@ -315,6 +315,49 @@ doi_walk_return:
}
/**
+ * calipso_validate - Validate a CALIPSO option
+ * @skb: the packet
+ * @option: the start of the option
+ *
+ * Description:
+ * This routine is called to validate a CALIPSO option.
+ * If the option is valid then a zero value is returned. If the
+ * option is invalid then a non-zero value is returned and
+ * representing the offset to the offending portion of the option.
+ *
+ * The caller should have already checked that the length of the
+ * option (including the TLV header) is >= 10 and that the catmap
+ * length is consistent with the option length.
+ *
+ * We leave checks on the level and categories to the socket layer.
+ */
+bool calipso_validate(const struct sk_buff *skb, const unsigned char *option)
+{
+ struct calipso_doi *doi_def;
+ int ret_val;
+ u16 crc, len = option[1] + 2;
+ static const u8 zero[2];
+
+ /* The original CRC runs over the option including the TLV header
+ * with the CRC-16 field (at offset 8) zeroed out.
+ */
+ crc = crc_ccitt(0xffff, option, 8);
+ crc = crc_ccitt(crc, zero, sizeof(zero));
+ if (len > 10)
+ crc = crc_ccitt(crc, option + 10, len - 10);
+ crc = ~crc;
+ if (option[8] != (crc & 0xff) || option[9] != ((crc >> 8) & 0xff))
+ return false;
+
+ rcu_read_lock();
+ doi_def = calipso_doi_search(get_unaligned_be32(option + 2));
+ ret_val = !!doi_def;
+ rcu_read_unlock();
+
+ return ret_val;
+}
+
+/**
* calipso_map_cat_hton - Perform a category mapping from host to network
* @doi_def: the DOI definition
* @secattr: the security attributes
diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index d5fd3e7..0f69cab 100644
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -43,6 +43,7 @@
#include <net/ndisc.h>
#include <net/ip6_route.h>
#include <net/addrconf.h>
+#include <net/calipso.h>
#if IS_ENABLED(CONFIG_IPV6_MIP6)
#include <net/xfrm.h>
#endif
@@ -603,6 +604,28 @@ drop:
return false;
}
+/* CALIPSO RFC 5570 */
+
+static bool ipv6_hop_calipso(struct sk_buff *skb, int optoff)
+{
+ const unsigned char *nh = skb_network_header(skb);
+
+ if (nh[optoff + 1] < 8)
+ goto drop;
+
+ if (nh[optoff + 6] * 4 + 8 > nh[optoff + 1])
+ goto drop;
+
+ if (!calipso_validate(skb, nh + optoff))
+ goto drop;
+
+ return true;
+
+drop:
+ kfree_skb(skb);
+ return false;
+}
+
static const struct tlvtype_proc tlvprochopopt_lst[] = {
{
.type = IPV6_TLV_ROUTERALERT,
@@ -612,6 +635,10 @@ static const struct tlvtype_proc tlvprochopopt_lst[] = {
.type = IPV6_TLV_JUMBO,
.func = ipv6_hop_jumbo,
},
+ {
+ .type = IPV6_TLV_CALIPSO,
+ .func = ipv6_hop_calipso,
+ },
{ -1, }
};
--
1.8.0
Powered by blists - more mailing lists