[NETFILTER]: ctnetlink: Fix dumping of helper name

Properly dump the helper name instead of internal kernel data.
Based on patch by Marcus Sundberg <marcus@ingate.com>.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/netfilter/nfnetlink_conntrack.h

@@ -131,6 +131,4 @@ enum ctattr_help {
 };
 #define CTA_HELP_MAX (__CTA_HELP_MAX - 1)
 
-#define CTA_HELP_MAXNAMESIZE	32
-
 #endif /* _IPCONNTRACK_NETLINK_H */

net/ipv4/netfilter/ip_conntrack_netlink.c

@@ -161,7 +161,7 @@ ctnetlink_dump_helpinfo(struct sk_buff *skb, const struct ip_conntrack *ct)
 		return 0;
 
 	nest_helper = NFA_NEST(skb, CTA_HELP);
-	NFA_PUT(skb, CTA_HELP_NAME, CTA_HELP_MAXNAMESIZE, &ct->helper->name);
+	NFA_PUT(skb, CTA_HELP_NAME, strlen(ct->helper->name), ct->helper->name);
 
 	if (ct->helper->to_nfattr)
 		ct->helper->to_nfattr(skb, ct);