From ca0a10672dad94aa1f89645f89eb6047b7bf2a19 Mon Sep 17 00:00:00 2001 From: Mathias Krause Date: Mon, 30 Sep 2013 22:05:07 +0200 Subject: [PATCH] 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 Signed-off-by: Pablo Neira Ayuso --- net/bridge/netfilter/ebt_ulog.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/net/bridge/netfilter/ebt_ulog.c b/net/bridge/netfilter/ebt_ulog.c index 518093802d1d..7c470c371e14 100644 --- a/net/bridge/netfilter/ebt_ulog.c +++ b/net/bridge/netfilter/ebt_ulog.c @@ -181,6 +181,7 @@ static void ebt_ulog_packet(struct net *net, unsigned int hooknr, 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 @@ static void ebt_ulog_packet(struct net *net, unsigned int hooknr, 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 @@ static void ebt_ulog_packet(struct net *net, unsigned int hooknr, 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(); -- 2.45.2