[NETLINK]: Clear padding in netlink messages

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

include/linux/netlink.h

@@ -168,6 +168,7 @@ __nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq, int type, int len, int flags)
 	nlh->nlmsg_flags = flags;
 	nlh->nlmsg_pid = pid;
 	nlh->nlmsg_seq = seq;
+	memset(NLMSG_DATA(nlh) + len, 0, NLMSG_ALIGN(size) - size);
 	return nlh;
 }
 

include/linux/rtnetlink.h

@@ -898,7 +898,9 @@ extern void __rta_fill(struct sk_buff *skb, int attrtype, int attrlen, const voi
 	memcpy(skb_put(skb, attrlen), data, attrlen); })
 
 #define RTA_PUT_NOHDR(skb, attrlen, data) \
-	RTA_APPEND(skb, RTA_ALIGN(attrlen), data)
+({	RTA_APPEND(skb, RTA_ALIGN(attrlen), data); \
+	memset(skb->tail - (RTA_ALIGN(attrlen) - attrlen), 0, \
+	       RTA_ALIGN(attrlen) - attrlen); })
 
 #define RTA_PUT_U8(skb, attrtype, value) \
 ({	u8 _tmp = (value); \
@@ -978,6 +980,7 @@ __rta_reserve(struct sk_buff *skb, int attrtype, int attrlen)
 	rta = (struct rtattr*)skb_put(skb, RTA_ALIGN(size));
 	rta->rta_type = attrtype;
 	rta->rta_len = size;
+	memset(RTA_DATA(rta) + attrlen, 0, RTA_ALIGN(size) - size);
 	return rta;
 }
 

net/core/rtnetlink.c

@@ -126,6 +126,7 @@ void __rta_fill(struct sk_buff *skb, int attrtype, int attrlen, const void *data
 	rta->rta_type = attrtype;
 	rta->rta_len = size;
 	memcpy(RTA_DATA(rta), data, attrlen);
+	memset(RTA_DATA(rta) + attrlen, 0, RTA_ALIGN(size) - size);
 }
 
 size_t rtattr_strlcpy(char *dest, const struct rtattr *rta, size_t size)