Patchwork [57/70] iscsi-target: fix heap buffer overflow on error

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Submitter Luis Henriques
Date June 4, 2013, 2:07 p.m.
Message ID <1370354846-14213-58-git-send-email-luis.henriques@canonical.com>
Download mbox | patch
Permalink /patch/248642/
State New
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Luis Henriques - June 4, 2013, 2:07 p.m.
3.5.7.14 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Kees Cook <keescook@chromium.org>

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@chromium.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Luis Henriques <luis.henriques@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(-)

Patch

diff --git a/drivers/target/iscsi/iscsi_target_parameters.c b/drivers/target/iscsi/iscsi_target_parameters.c
index ed5241e..18c086d 100644
--- a/drivers/target/iscsi/iscsi_target_parameters.c
+++ b/drivers/target/iscsi/iscsi_target_parameters.c
@@ -713,9 +713,9 @@  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);
@@ -1554,8 +1554,6 @@  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 6a37fd6..83eed65 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;