netfilter: ensure number of counters is >0 in do_replace()

[cascardo/linux.git] / net / ipv4 / netfilter / ip_tables.c

diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index c69db7f..2d0e265 100644 (file)
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -1262,6 +1262,9 @@ do_replace(struct net *net, const void __user *user, unsigned int len)
        /* overflow check */
        if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
                return -ENOMEM;
+       if (tmp.num_counters == 0)
+               return -EINVAL;
+
        tmp.name[sizeof(tmp.name)-1] = 0;
 
        newinfo = xt_alloc_table_info(tmp.size);
@@ -1809,6 +1812,9 @@ compat_do_replace(struct net *net, void __user *user, unsigned int len)
                return -ENOMEM;
        if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
                return -ENOMEM;
+       if (tmp.num_counters == 0)
+               return -EINVAL;
+
        tmp.name[sizeof(tmp.name)-1] = 0;
 
        newinfo = xt_alloc_table_info(tmp.size);