netfilter: log: netns NULL ptr bug when calling from conntrack
Since (69b34fb netfilter: xt_LOG: add net namespace support
for xt_LOG), we hit this:
[ 4224.708977] BUG: unable to handle kernel NULL pointer dereference at 0000000000000388
[ 4224.709074] IP: [<ffffffff8147f699>] ipt_log_packet+0x29/0x270
when callling log functions from conntrack both in and out
are NULL i.e. the net pointer is invalid.
Adding struct net *net in call to nf_logfn() will secure that
there always is a vaild net ptr.
Reported as netfilter's bugzilla bug 818:
https://bugzilla.netfilter.org/show_bug.cgi?id=818
Reported-by: Ronald <ronald645@gmail.com>
Signed-off-by: Hans Schillstrom <hans@schillstrom.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 fc1905c..df0364a 100644
--- a/net/bridge/netfilter/ebt_ulog.c
+++ b/net/bridge/netfilter/ebt_ulog.c
@@ -131,14 +131,16 @@
return skb;
}
-static void ebt_ulog_packet(unsigned int hooknr, const struct sk_buff *skb,
- const struct net_device *in, const struct net_device *out,
- const struct ebt_ulog_info *uloginfo, const char *prefix)
+static void ebt_ulog_packet(struct net *net, unsigned int hooknr,
+ const struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ const struct ebt_ulog_info *uloginfo,
+ const char *prefix)
{
ebt_ulog_packet_msg_t *pm;
size_t size, copy_len;
struct nlmsghdr *nlh;
- struct net *net = dev_net(in ? in : out);
struct ebt_ulog_net *ebt = ebt_ulog_pernet(net);
unsigned int group = uloginfo->nlgroup;
ebt_ulog_buff_t *ub = &ebt->ulog_buffers[group];
@@ -233,7 +235,7 @@
}
/* this function is registered with the netfilter core */
-static void ebt_log_packet(u_int8_t pf, unsigned int hooknum,
+static void ebt_log_packet(struct net *net, u_int8_t pf, unsigned int hooknum,
const struct sk_buff *skb, const struct net_device *in,
const struct net_device *out, const struct nf_loginfo *li,
const char *prefix)
@@ -252,13 +254,15 @@
strlcpy(loginfo.prefix, prefix, sizeof(loginfo.prefix));
}
- ebt_ulog_packet(hooknum, skb, in, out, &loginfo, prefix);
+ ebt_ulog_packet(net, hooknum, skb, in, out, &loginfo, prefix);
}
static unsigned int
ebt_ulog_tg(struct sk_buff *skb, const struct xt_action_param *par)
{
- ebt_ulog_packet(par->hooknum, skb, par->in, par->out,
+ struct net *net = dev_net(par->in ? par->in : par->out);
+
+ ebt_ulog_packet(net, par->hooknum, skb, par->in, par->out,
par->targinfo, NULL);
return EBT_CONTINUE;
}