netfilter: ebt_ulog: fix info leaks
The ulog messages leak heap bytes by the means of padding bytes and
incompletely filled string arrays. Fix those by memset(0)'ing the
whole struct before filling it.
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/net/bridge/netfilter/ebt_ulog.c b/net/bridge/netfilter/ebt_ulog.c
index 5180938..7c470c3 100644
--- a/net/bridge/netfilter/ebt_ulog.c
+++ b/net/bridge/netfilter/ebt_ulog.c
@@ -181,6 +181,7 @@
ub->qlen++;
pm = nlmsg_data(nlh);
+ memset(pm, 0, sizeof(*pm));
/* Fill in the ulog data */
pm->version = EBT_ULOG_VERSION;
@@ -193,8 +194,6 @@
pm->hook = hooknr;
if (uloginfo->prefix != NULL)
strcpy(pm->prefix, uloginfo->prefix);
- else
- *(pm->prefix) = '\0';
if (in) {
strcpy(pm->physindev, in->name);
@@ -204,16 +203,14 @@
strcpy(pm->indev, br_port_get_rcu(in)->br->dev->name);
else
strcpy(pm->indev, in->name);
- } else
- pm->indev[0] = pm->physindev[0] = '\0';
+ }
if (out) {
/* If out exists, then out is a bridge port */
strcpy(pm->physoutdev, out->name);
/* rcu_read_lock()ed by nf_hook_slow */
strcpy(pm->outdev, br_port_get_rcu(out)->br->dev->name);
- } else
- pm->outdev[0] = pm->physoutdev[0] = '\0';
+ }
if (skb_copy_bits(skb, -ETH_HLEN, pm->data, copy_len) < 0)
BUG();