This is a note to let you know that I've just added the patch titled
iscsi-target: Reject mutual authentication with reflected CHAP_C
to the 3.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
iscsi-target-reject-mutual-authentication-with-reflected-chap_c.patch
and it can be found in the queue-3.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 1d2b60a5545942b1376cb48c1d55843d71e3a08f Mon Sep 17 00:00:00 2001
From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
Date: Thu, 5 Jun 2014 18:08:57 -0700
Subject: iscsi-target: Reject mutual authentication with reflected CHAP_C
From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
commit 1d2b60a5545942b1376cb48c1d55843d71e3a08f upstream.
This patch adds an explicit check in chap_server_compute_md5() to ensure
the CHAP_C value received from the initiator during mutual authentication
does not match the original CHAP_C provided by the target.
This is in line with RFC-3720, section 8.2.1:
Originators MUST NOT reuse the CHAP challenge sent by the Responder
for the other direction of a bidirectional authentication.
Responders MUST check for this condition and close the iSCSI TCP
connection if it occurs.
Reported-by: Tejas Vaykole <tejas.vaykole@xxxxxxxxxxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/target/iscsi/iscsi_target_auth.c | 10 ++++++++++
1 file changed, 10 insertions(+)
--- a/drivers/target/iscsi/iscsi_target_auth.c
+++ b/drivers/target/iscsi/iscsi_target_auth.c
@@ -342,6 +342,16 @@ static int chap_server_compute_md5(
goto out;
}
/*
+ * During mutual authentication, the CHAP_C generated by the
+ * initiator must not match the original CHAP_C generated by
+ * the target.
+ */
+ if (!memcmp(challenge_binhex, chap->challenge, CHAP_CHALLENGE_LENGTH)) {
+ pr_err("initiator CHAP_C matches target CHAP_C, failing"
+ " login attempt\n");
+ goto out;
+ }
+ /*
* Generate CHAP_N and CHAP_R for mutual authentication.
*/
tfm = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
Patches currently in stable-queue which might be from nab@xxxxxxxxxxxxxxx are
queue-3.4/iscsi-target-reject-mutual-authentication-with-reflected-chap_c.patch
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