--- /dev/null
+From 1d2b60a5545942b1376cb48c1d55843d71e3a08f Mon Sep 17 00:00:00 2001
+From: Nicholas Bellinger <nab@linux-iscsi.org>
+Date: Thu, 5 Jun 2014 18:08:57 -0700
+Subject: iscsi-target: Reject mutual authentication with reflected CHAP_C
+
+From: Nicholas Bellinger <nab@linux-iscsi.org>
+
+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@calsoftinc.com>
+Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ 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);