netdev - [PATCH] (02/06/08 Linus git) Smack unlabeled outgoing ambient packets

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

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

Message-ID: <47AB3AEB.5010308@schaufler-ca.com>
Date:	Thu, 07 Feb 2008 09:07:55 -0800
From:	Casey Schaufler <casey@...aufler-ca.com>
To:	akpm@...ux-foundation.org, torvalds@...ux-foundation.org,
	mingo@...e.hu
CC:	davem@...emloft.net, netdev@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH] (02/06/08 Linus git) Smack unlabeled outgoing ambient packets

From: Casey Schaufler <casey@...aufler-ca.com>

Smack uses CIPSO labeling, but allows for unlabeled packets
by specifying an "ambient" label that is applied to incoming
unlabeled packets. Because the other end of the connection
may dislike IP options, and ssh is one know application that
behaves thus, it is prudent to respond in kind. This patch
changes the network labeling behavior such that an outgoing
packet that would be given a CIPSO label that matches the
ambient label is left unlabeled.

Signed-off-by: Casey Schaufler <casey@...aufler-ca.com>

---

 security/smack/smack_lsm.c |    9 +++++++++
 1 file changed, 9 insertions(+)

diff -uprN -X linux-2.6.25-g0206-base//Documentation/dontdiff linux-2.6.25-g0206-base/security/smack/smack_lsm.c linux-2.6.25-g0206/security/smack/smack_lsm.c
--- linux-2.6.25-g0206-base/security/smack/smack_lsm.c	2008-02-06 16:01:43.000000000 -0800
+++ linux-2.6.25-g0206/security/smack/smack_lsm.c	2008-02-06 18:39:55.000000000 -0800
@@ -1276,6 +1276,12 @@ static void smack_to_secattr(char *smack
  * Convert the outbound smack value (smk_out) to a
  * secattr and attach it to the socket.
  *
+ * If the label is the ambient label do not set the secattr.
+ * Thus, all ambient packets are unlabeled and all unlabeled
+ * packets are ambient. This permits unlabeled responces to
+ * unlabeled requests without knowing on a per-packet basis
+ * if the packet was labeled ambient or was unlabeled.
+ *
  * Returns 0 on success or an error code
  */
 static int smack_netlabel(struct sock *sk)
@@ -1284,6 +1290,9 @@ static int smack_netlabel(struct sock *s
 	struct netlbl_lsm_secattr secattr;
 	int rc = 0;
 
+	if (strncmp(ssp->smk_out, smack_net_ambient, SMK_MAXLEN) == 0)
+		return 0;
+
 	netlbl_secattr_init(&secattr);
 	smack_to_secattr(ssp->smk_out, &secattr);
 	if (secattr.flags != NETLBL_SECATTR_NONE)

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html