releases/2.6.34.15/HID-zeroplus-validate-output-report-details.patch

From a735b2aaa5a3f394031e10868e8c9c3f83e3ef86 Mon Sep 17 00:00:00 2001
From: Kees Cook <keescook@chromium.org>
Date: Wed, 11 Sep 2013 21:56:51 +0200
Subject: [PATCH] HID: zeroplus: validate output report details

commit 78214e81a1bf43740ce89bb5efda78eac2f8ef83 upstream.

The zeroplus HID driver was not checking the size of allocated values
in fields it used. A HID device could send a malicious output report
that would cause the driver to write beyond the output report allocation
during initialization, causing a heap overflow:

[ 1442.728680] usb 1-1: New USB device found, idVendor=0c12, idProduct=0005
...
[ 1466.243173] BUG kmalloc-192 (Tainted: G        W   ): Redzone overwritten

CVE-2013-2889

Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
 drivers/hid/hid-zpff.c | 18 +++++-------------
 1 file changed, 5 insertions(+), 13 deletions(-)

diff --git a/drivers/hid/hid-zpff.c b/drivers/hid/hid-zpff.c
index b7acceabba80..a24f9fb43c34 100644
--- a/drivers/hid/hid-zpff.c
+++ b/drivers/hid/hid-zpff.c
@@ -69,21 +69,13 @@ static int zpff_init(struct hid_device *hid)
 	struct hid_report *report;
 	struct hid_input *hidinput = list_entry(hid->inputs.next,
 						struct hid_input, list);
-	struct list_head *report_list =
-			&hid->report_enum[HID_OUTPUT_REPORT].report_list;
 	struct input_dev *dev = hidinput->input;
-	int error;
+	int i, error;
 
-	if (list_empty(report_list)) {
-		dev_err(&hid->dev, "no output report found\n");
-		return -ENODEV;
-	}
-
-	report = list_entry(report_list->next, struct hid_report, list);
-
-	if (report->maxfield < 4) {
-		dev_err(&hid->dev, "not enough fields in report\n");
-		return -ENODEV;
+	for (i = 0; i < 4; i++) {
+		report = hid_validate_values(hid, HID_OUTPUT_REPORT, 0, i, 1);
+		if (!report)
+			return -ENODEV;
 	}
 
 	zpff = kzalloc(sizeof(struct zpff_device), GFP_KERNEL);
-- 
1.8.5.2