1 files changed, 53 insertions, 0 deletions
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
index 2675d580c490..e0aa7c1d0224 100644
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -702,6 +702,56 @@ int xt_check_entry_offsets(const void *base,
 }
 EXPORT_SYMBOL(xt_check_entry_offsets);
 
+/**
+ * xt_alloc_entry_offsets - allocate array to store rule head offsets
+ *
+ * @size: number of entries
+ *
+ * Return: NULL or kmalloc'd or vmalloc'd array
+ */
+unsigned int *xt_alloc_entry_offsets(unsigned int size)
+{
+	unsigned int *off;
+
+	off = kcalloc(size, sizeof(unsigned int), GFP_KERNEL | __GFP_NOWARN);
+
+	if (off)
+		return off;
+
+	if (size < (SIZE_MAX / sizeof(unsigned int)))
+		off = vmalloc(size * sizeof(unsigned int));
+
+	return off;
+}
+EXPORT_SYMBOL(xt_alloc_entry_offsets);
+
+/**
+ * xt_find_jump_offset - check if target is a valid jump offset
+ *
+ * @offsets: array containing all valid rule start offsets of a rule blob
+ * @target: the jump target to search for
+ * @size: entries in @offset
+ */
+bool xt_find_jump_offset(const unsigned int *offsets,
+			 unsigned int target, unsigned int size)
+{
+	int m, low = 0, hi = size;
+
+	while (hi > low) {
+		m = (low + hi) / 2u;
+
+		if (offsets[m] > target)
+			hi = m;
+		else if (offsets[m] < target)
+			low = m + 1;
+		else
+			return true;
+	}
+
+	return false;
+}
+EXPORT_SYMBOL(xt_find_jump_offset);
+
 int xt_check_target(struct xt_tgchk_param *par,
 		    unsigned int size, u_int8_t proto, bool inv_proto)
 {
@@ -1460,6 +1510,9 @@ xt_hook_ops_alloc(const struct xt_table *table, nf_hookfn *fn)
 	uint8_t hooknum;
 	struct nf_hook_ops *ops;
 
+	if (!num_hooks)
+		return ERR_PTR(-EINVAL);
+
 	ops = kmalloc(sizeof(*ops) * num_hooks, GFP_KERNEL);
 	if (ops == NULL)
 		return ERR_PTR(-ENOMEM);