1 files changed, 114 insertions, 10 deletions

diff --git a/net/netlink/attr.c b/net/netlink/attr.c
index dddbd15135a8..004139557e09 100644
--- a/net/netlink/attr.c
+++ b/net/netlink/attr.c
@@ -20,7 +20,6 @@ static u16 nla_attr_minlen[NLA_TYPE_MAX+1] __read_mostly = {
         [NLA_U16]       = sizeof(u16),
         [NLA_U32]       = sizeof(u32),
         [NLA_U64]       = sizeof(u64),
-        [NLA_STRING]    = 1,
         [NLA_NESTED]    = NLA_HDRLEN,
 };
 
@@ -28,7 +27,7 @@ static int validate_nla(struct nlattr *nla, int maxtype,
                         struct nla_policy *policy)
 {
         struct nla_policy *pt;
-        int minlen = 0;
+        int minlen = 0, attrlen = nla_len(nla);
 
         if (nla->nla_type <= 0 || nla->nla_type > maxtype)
                 return 0;
@@ -37,16 +36,46 @@ static int validate_nla(struct nlattr *nla, int maxtype,
 
         BUG_ON(pt->type > NLA_TYPE_MAX);
 
-        if (pt->minlen)
-                minlen = pt->minlen;
-        else if (pt->type != NLA_UNSPEC)
-                minlen = nla_attr_minlen[pt->type];
+        switch (pt->type) {
+        case NLA_FLAG:
+                if (attrlen > 0)
+                        return -ERANGE;
+                break;
 
-        if (pt->type == NLA_FLAG && nla_len(nla) > 0)
-                return -ERANGE;
+        case NLA_NUL_STRING:
+                if (pt->len)
+                        minlen = min_t(int, attrlen, pt->len + 1);
+                else
+                        minlen = attrlen;
 
-        if (nla_len(nla) < minlen)
-                return -ERANGE;
+                if (!minlen || memchr(nla_data(nla), '\0', minlen) == NULL)
+                        return -EINVAL;
+                /* fall through */
+
+        case NLA_STRING:
+                if (attrlen < 1)
+                        return -ERANGE;
+
+                if (pt->len) {
+                        char *buf = nla_data(nla);
+
+                        if (buf[attrlen - 1] == '\0')
+                                attrlen--;
+
+                        if (attrlen > pt->len)
+                                return -ERANGE;
+                }
+                break;
+
+        default:
+                if (pt->len)
+                        minlen = pt->len;
+                else if (pt->type != NLA_UNSPEC)
+                        minlen = nla_attr_minlen[pt->type];
+
+                if (attrlen < minlen)
+                        return -ERANGE;
+        }
 
         return 0;
 }
@@ -255,6 +284,26 @@ struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen)
 }
 
 /**
+ * __nla_reserve_nohdr - reserve room for attribute without header
+ * @skb: socket buffer to reserve room on
+ * @attrlen: length of attribute payload
+ *
+ * Reserves room for attribute payload without a header.
+ *
+ * The caller is responsible to ensure that the skb provides enough
+ * tailroom for the payload.
+ */
+void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen)
+{
+        void *start;
+
+        start = skb_put(skb, NLA_ALIGN(attrlen));
+        memset(start, 0, NLA_ALIGN(attrlen));
+
+        return start;
+}
+
+/**
  * nla_reserve - reserve room for attribute on the skb
  * @skb: socket buffer to reserve room on
  * @attrtype: attribute type
@@ -275,6 +324,24 @@ struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen)
 }
 
 /**
+ * nla_reserve - reserve room for attribute without header
+ * @skb: socket buffer to reserve room on
+ * @len: length of attribute payload
+ *
+ * Reserves room for attribute payload without a header.
+ *
+ * Returns NULL if the tailroom of the skb is insufficient to store
+ * the attribute payload.
+ */
+void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen)
+{
+        if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen)))
+                return NULL;
+
+        return __nla_reserve_nohdr(skb, attrlen);
+}
+
+/**
  * __nla_put - Add a netlink attribute to a socket buffer
  * @skb: socket buffer to add attribute to
  * @attrtype: attribute type
@@ -293,6 +360,22 @@ void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
         memcpy(nla_data(nla), data, attrlen);
 }
 
+/**
+ * __nla_put_nohdr - Add a netlink attribute without header
+ * @skb: socket buffer to add attribute to
+ * @attrlen: length of attribute payload
+ * @data: head of attribute payload
+ *
+ * The caller is responsible to ensure that the skb provides enough
+ * tailroom for the attribute payload.
+ */
+void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data)
+{
+        void *start;
+
+        start = __nla_reserve_nohdr(skb, attrlen);
+        memcpy(start, data, attrlen);
+}
 
 /**
  * nla_put - Add a netlink attribute to a socket buffer
@@ -313,15 +396,36 @@ int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data)
         return 0;
 }
 
+/**
+ * nla_put_nohdr - Add a netlink attribute without header
+ * @skb: socket buffer to add attribute to
+ * @attrlen: length of attribute payload
+ * @data: head of attribute payload
+ *
+ * Returns -1 if the tailroom of the skb is insufficient to store
+ * the attribute payload.
+ */
+int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data)
+{
+        if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen)))
+                return -1;
+
+        __nla_put_nohdr(skb, attrlen, data);
+        return 0;
+}
 
 EXPORT_SYMBOL(nla_validate);
 EXPORT_SYMBOL(nla_parse);
 EXPORT_SYMBOL(nla_find);
 EXPORT_SYMBOL(nla_strlcpy);
 EXPORT_SYMBOL(__nla_reserve);
+EXPORT_SYMBOL(__nla_reserve_nohdr);
 EXPORT_SYMBOL(nla_reserve);
+EXPORT_SYMBOL(nla_reserve_nohdr);
 EXPORT_SYMBOL(__nla_put);
+EXPORT_SYMBOL(__nla_put_nohdr);
 EXPORT_SYMBOL(nla_put);
+EXPORT_SYMBOL(nla_put_nohdr);
 EXPORT_SYMBOL(nla_memcpy);
 EXPORT_SYMBOL(nla_memcmp);
 EXPORT_SYMBOL(nla_strcmp);