openrisc: fix arbitrary kernel memory access via or1k_atomic syscallgrafted

sys_or1k_atomic() (syscall 244 in the "or1k" ABI) takes two user
pointers, v1 and v2, and swaps the words they point to in hand-written
assembly.

    l.lwz   r29,0(r4)
    l.lwz   r27,0(r5)
    l.sw    0(r4),r27
    l.sw    0(r5),r29

The pointers are not checked with access_ok(). The four memory
accesses also have no exception table entries.

A caller passes a kernel address as either pointer, and the syscall
reads from and writes to it directly.

This gives an unprivileged process a kernel read/write primitive. It
overwrites kernel data such as the sys_call_table, gaining code
execution in kernel context.

Check both pointers before entering the critical section. Add fixups
for the four memory accesses so faults on valid but unmapped user
addresses return -EFAULT.

[shorne@gmail.com: fix comment style]
Fixes: 9d02a4283e9c ("OpenRISC: Boot code")
Cc: stable@vger.kernel.org
Signed-off-by: Ali Ahmet Memis <ali@iusegentoo.com>
Signed-off-by: Stafford Horne <shorne@gmail.com>

1 files changed, 82 insertions, 0 deletions

diff --git a/drivers/hid/hid-topseed.c b/drivers/hid/hid-topseed.c
new file mode 100644
index 000000000..645e36cd8
--- /dev/null
+++ b/drivers/hid/hid-topseed.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  HID driver for TopSeed Cyberlink remote
+ *
+ *  Copyright (c) 2008 Lev Babiev
+ *  based on hid-cherry driver
+ *
+ *  Modified to also support BTC "Emprex 3009URF III Vista MCE Remote" by
+ *  Wayne Thomas 2010.
+ *
+ *  Modified to support Conceptronic CLLRCMCE by
+ *  Kees Bakker 2010.
+ */
+
+/*
+ */
+
+#include <linux/device.h>
+#include <linux/hid.h>
+#include <linux/module.h>
+
+#include "hid-ids.h"
+
+#define ts_map_key_clear(c)	hid_map_usage_clear(hi, usage, bit, max, \
+					EV_KEY, (c))
+static int ts_input_mapping(struct hid_device *hdev, struct hid_input *hi,
+		struct hid_field *field, struct hid_usage *usage,
+		unsigned long **bit, int *max)
+{
+	if ((usage->hid & HID_USAGE_PAGE) != HID_UP_LOGIVENDOR)
+		return 0;
+
+	switch (usage->hid & HID_USAGE) {
+	case 0x00c: ts_map_key_clear(KEY_WLAN);		break;
+	case 0x00d: ts_map_key_clear(KEY_MEDIA);	break;
+	case 0x010: ts_map_key_clear(KEY_ZOOM);		break;
+	case 0x024: ts_map_key_clear(KEY_MENU);		break;
+	case 0x025: ts_map_key_clear(KEY_TV);		break;
+	case 0x027: ts_map_key_clear(KEY_MODE);		break;
+	case 0x031: ts_map_key_clear(KEY_AUDIO);	break;
+	case 0x032: ts_map_key_clear(KEY_TEXT);		break;
+	case 0x033: ts_map_key_clear(KEY_CHANNEL);	break;
+	case 0x047: ts_map_key_clear(KEY_MP3);		break;
+	case 0x048: ts_map_key_clear(KEY_TV2);		break;
+	case 0x049: ts_map_key_clear(KEY_CAMERA);	break;
+	case 0x04a: ts_map_key_clear(KEY_VIDEO);	break;
+	case 0x04b: ts_map_key_clear(KEY_ANGLE);	break;
+	case 0x04c: ts_map_key_clear(KEY_LANGUAGE);	break;
+	case 0x04d: ts_map_key_clear(KEY_SUBTITLE);	break;
+	case 0x050: ts_map_key_clear(KEY_RADIO);	break;
+	case 0x05a: ts_map_key_clear(KEY_TEXT);		break;
+	case 0x05b: ts_map_key_clear(KEY_RED);		break;
+	case 0x05c: ts_map_key_clear(KEY_GREEN);	break;
+	case 0x05d: ts_map_key_clear(KEY_YELLOW);	break;
+	case 0x05e: ts_map_key_clear(KEY_BLUE);		break;
+	default:
+		return 0;
+	}
+
+	return 1;
+}
+
+static const struct hid_device_id ts_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_TOPSEED, USB_DEVICE_ID_TOPSEED_CYBERLINK) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_BTC, USB_DEVICE_ID_BTC_EMPREX_REMOTE) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_BTC, USB_DEVICE_ID_BTC_EMPREX_REMOTE_2) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_TOPSEED2, USB_DEVICE_ID_TOPSEED2_RF_COMBO) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_CHICONY, USB_DEVICE_ID_CHICONY_WIRELESS) },
+	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_CHICONY, USB_DEVICE_ID_CHICONY_TOSHIBA_WT10A) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, ts_devices);
+
+static struct hid_driver ts_driver = {
+	.name = "topseed",
+	.id_table = ts_devices,
+	.input_mapping = ts_input_mapping,
+};
+module_hid_driver(ts_driver);
+
+MODULE_DESCRIPTION("HID driver for TopSeed Cyberlink remote");
+MODULE_LICENSE("GPL");