netfilter: ipset: Alignment problem between 64bit kernel 32bit userspace

Sven-Haegar Koch reported the issue:

sims:~# iptables -A OUTPUT -m set --match-set testset src -j ACCEPT
iptables: Invalid argument. Run `dmesg' for more information.

In syslog:
x_tables: ip_tables: set.3 match: invalid size 48 (kernel) != (user) 32

which was introduced by the counter extension in ipset.

The patch fixes the alignment issue with introducing a new set match
revision with the fixed underlying 'struct ip_set_counter_match'
structure.

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

2 files changed, 18 insertions, 3 deletions

diff --git a/include/uapi/linux/netfilter/ipset/ip_set.h b/include/uapi/linux/netfilter/ipset/ip_set.h
index ca03119111a2..5ab4e60894cf 100644
--- a/include/uapi/linux/netfilter/ipset/ip_set.h
+++ b/include/uapi/linux/netfilter/ipset/ip_set.h
@@ -256,11 +256,17 @@ enum {
         IPSET_COUNTER_GT,
 };
 
-struct ip_set_counter_match {
+/* Backward compatibility for set match v3 */
+struct ip_set_counter_match0 {
         __u8 op;
         __u64 value;
 };
 
+struct ip_set_counter_match {
+        __aligned_u64 value;
+        __u8 op;
+};
+
 /* Interface to iptables/ip6tables */
 
 #define SO_IP_SET               83
diff --git a/include/uapi/linux/netfilter/xt_set.h b/include/uapi/linux/netfilter/xt_set.h
index d6a1df1f2947..d4e02348384c 100644
--- a/include/uapi/linux/netfilter/xt_set.h
+++ b/include/uapi/linux/netfilter/xt_set.h
@@ -66,8 +66,8 @@ struct xt_set_info_target_v2 {
 
 struct xt_set_info_match_v3 {
         struct xt_set_info match_set;
-        struct ip_set_counter_match packets;
-        struct ip_set_counter_match bytes;
+        struct ip_set_counter_match0 packets;
+        struct ip_set_counter_match0 bytes;
         __u32 flags;
 };
 
@@ -81,4 +81,13 @@ struct xt_set_info_target_v3 {
         __u32 timeout;
 };
 
+/* Revision 4 match */
+
+struct xt_set_info_match_v4 {
+        struct xt_set_info match_set;
+        struct ip_set_counter_match packets;
+        struct ip_set_counter_match bytes;
+        __u32 flags;
+};
+
 #endif /*_XT_SET_H*/