ipv4: netfilter: arp_tables: fix information leak to userland

Structure arpt_getinfo is copied to userland with the field "name"
that has the last elements unitialized.  It leads to leaking of
contents of kernel stack memory.

Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

1 files changed, 1 insertions, 0 deletions

diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index 3cad2591ace0..3fac340a28d5 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -927,6 +927,7 @@ static int get_info(struct net *net, void __user *user,
                         private = &tmp;
                 }
 #endif
+                memset(&info, 0, sizeof(info));
                 info.valid_hooks = t->valid_hooks;
                 memcpy(info.hook_entry, private->hook_entry,
                        sizeof(info.hook_entry));