oss-security - use-after-free in src/libnetfilter

Follow @Openwall on Twitter for new release announcements and other news

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20150421025710.GA24209@hunt>
Date: Mon, 20 Apr 2015 19:57:10 -0700
From: Seth Arnold <seth.arnold@...onical.com>
To: pablo@...filter.org
Cc: oss-security@...ts.openwall.com, security@...ntu.com
Subject: use-after-free in src/libnetfilter_cthelper.c

Hello Pablo, all,

I noticed a use-after-free in src/libnetfilter_cthelper.c:

void nfct_helper_free(struct nfct_helper *h)
{
        int i;

        free(h);
        for (i=0; i<NF_CT_HELPER_CLASS_MAX; i++) {
                if (h->expect_policy[i])
                        free(h->expect_policy[i]);
        }
}

A simple fix would move the free(h) line below the for() loop.

Does this issue deserve a CVE? Determining exploitability is not my
expertise.

A simple browsable version can be found at:
http://sources.debian.net/src/libnetfilter-cthelper/1.0.0-1/src/libnetfilter_cthelper.c/?hl=109#L108

Some callers of this function can be found in the conntrack package:
https://codesearch.debian.net/results/nfct_helper_free%20package%3Aconntrack/page_0

Thanks

Download attachment "signature.asc" of type "application/pgp-signature" (474 bytes)

Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.