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 3.15-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-3.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.


>From 1d2b60a5545942b1376cb48c1d55843d71e3a08f Mon Sep 17 00:00:00 2001
From: Nicholas Bellinger <[email protected]>
Date: Thu, 5 Jun 2014 18:08:57 -0700
Subject: iscsi-target: Reject mutual authentication with reflected CHAP_C

From: Nicholas Bellinger <[email protected]>

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 <[email protected]>
Signed-off-by: Nicholas Bellinger <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 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
@@ -314,6 +314,16 @@ 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 [email protected] are

queue-3.15/target-fix-null-pointer-dereference-for-xcopy-in-target_put_sess_cmd.patch
queue-3.15/iscsi-target-reject-mutual-authentication-with-reflected-chap_c.patch
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