netfilter: ipt_ULOG: fix non-null terminated string in the nf_log path

If nf_log uses ipt_ULOG as logging output, we can deliver non-null
terminated strings to user-space since the maximum length of the
prefix that is passed by nf_log is NF_LOG_PREFIXLEN but pm->prefix
is 32 bytes long (ULOG_PREFIX_LEN).

This is actually happening already from nf_conntrack_tcp if ipt_ULOG
is used, since it is passing strings longer than 32 bytes.

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Chen Gang 2013-05-23 01:50:46 +00:00 committed by Pablo Neira Ayuso
parent 2a7851bffb
commit 4f36ea6eed

View File

@ -231,8 +231,10 @@ static void ipt_ulog_packet(struct net *net,
put_unaligned(tv.tv_usec, &pm->timestamp_usec);
put_unaligned(skb->mark, &pm->mark);
pm->hook = hooknum;
if (prefix != NULL)
strncpy(pm->prefix, prefix, sizeof(pm->prefix));
if (prefix != NULL) {
strncpy(pm->prefix, prefix, sizeof(pm->prefix) - 1);
pm->prefix[sizeof(pm->prefix) - 1] = '\0';
}
else if (loginfo->prefix[0] != '\0')
strncpy(pm->prefix, loginfo->prefix, sizeof(pm->prefix));
else