[ 3.8.y.z extended stable ] Patch "iscsi-target: fix heap buffer overflow on error" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    iscsi-target: fix heap buffer overflow on error

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.2.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From dc471a1b1045c0c60f892411c675195cdeeefbf6 Mon Sep 17 00:00:00 2001
From: Kees Cook <keescook at chromium.org>
Date: Thu, 23 May 2013 10:32:17 -0700
Subject: iscsi-target: fix heap buffer overflow on error

commit cea4dcfdad926a27a18e188720efe0f2c9403456 upstream.

If a key was larger than 64 bytes, as checked by iscsi_check_key(), the
error response packet, generated by iscsi_add_notunderstood_response(),
would still attempt to copy the entire key into the packet, overflowing
the structure on the heap.

Remote preauthentication kernel memory corruption was possible if a
target was configured and listening on the network.

CVE-2013-2850

Signed-off-by: Kees Cook <keescook at chromium.org>
Signed-off-by: Nicholas Bellinger <nab at linux-iscsi.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/target/iscsi/iscsi_target_parameters.c | 8 +++-----
 drivers/target/iscsi/iscsi_target_parameters.h | 4 +++-
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/target/iscsi/iscsi_target_parameters.c b/drivers/target/iscsi/iscsi_target_parameters.c
index d891642..b8fa6aa 100644
--- a/drivers/target/iscsi/iscsi_target_parameters.c
+++ b/drivers/target/iscsi/iscsi_target_parameters.c
@@ -712,9 +712,9 @@ static int iscsi_add_notunderstood_response(
 	}
 	INIT_LIST_HEAD(&extra_response->er_list);

-	strncpy(extra_response->key, key, strlen(key) + 1);
-	strncpy(extra_response->value, NOTUNDERSTOOD,
-			strlen(NOTUNDERSTOOD) + 1);
+	strlcpy(extra_response->key, key, sizeof(extra_response->key));
+	strlcpy(extra_response->value, NOTUNDERSTOOD,
+		sizeof(extra_response->value));

 	list_add_tail(&extra_response->er_list,
 			&param_list->extra_response_list);
@@ -1583,8 +1583,6 @@ int iscsi_decode_text_input(

 		if (phase & PHASE_SECURITY) {
 			if (iscsi_check_for_auth_key(key) > 0) {
-				char *tmpptr = key + strlen(key);
-				*tmpptr = '=';
 				kfree(tmpbuf);
 				return 1;
 			}
diff --git a/drivers/target/iscsi/iscsi_target_parameters.h b/drivers/target/iscsi/iscsi_target_parameters.h
index 1e1b750..2c536a0 100644
--- a/drivers/target/iscsi/iscsi_target_parameters.h
+++ b/drivers/target/iscsi/iscsi_target_parameters.h
@@ -1,8 +1,10 @@
 #ifndef ISCSI_PARAMETERS_H
 #define ISCSI_PARAMETERS_H

+#include <scsi/iscsi_proto.h>
+
 struct iscsi_extra_response {
-	char key[64];
+	char key[KEY_MAXLEN];
 	char value[32];
 	struct list_head er_list;
 } ____cacheline_aligned;
--
1.8.1.2