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, 156 insertions, 0 deletions

diff --git a/drivers/hid/hid-chicony.c b/drivers/hid/hid-chicony.c
new file mode 100644
index 000000000..5776ec2e7
--- /dev/null
+++ b/drivers/hid/hid-chicony.c
@@ -0,0 +1,156 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  HID driver for some chicony "special" devices
+ *
+ *  Copyright (c) 1999 Andreas Gal
+ *  Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
+ *  Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
+ *  Copyright (c) 2006-2007 Jiri Kosina
+ *  Copyright (c) 2007 Paul Walmsley
+ *  Copyright (c) 2008 Jiri Slaby
+ */
+
+/*
+ */
+
+#include <linux/device.h>
+#include <linux/input.h>
+#include <linux/hid.h>
+#include <linux/module.h>
+#include <linux/usb.h>
+
+#include "hid-ids.h"
+
+#define CH_WIRELESS_CTL_REPORT_ID	0x11
+
+static int ch_report_wireless(struct hid_report *report, u8 *data, int size)
+{
+	struct hid_device *hdev = report->device;
+	struct input_dev *input;
+
+	if (report->id != CH_WIRELESS_CTL_REPORT_ID || report->maxfield != 1)
+		return 0;
+
+	input = report->field[0]->hidinput->input;
+	if (!input) {
+		hid_warn(hdev, "can't find wireless radio control's input");
+		return 0;
+	}
+
+	input_report_key(input, KEY_RFKILL, 1);
+	input_sync(input);
+	input_report_key(input, KEY_RFKILL, 0);
+	input_sync(input);
+
+	return 1;
+}
+
+static int ch_raw_event(struct hid_device *hdev,
+		struct hid_report *report, u8 *data, int size)
+{
+	if (report->application == HID_GD_WIRELESS_RADIO_CTLS)
+		return ch_report_wireless(report, data, size);
+
+	return 0;
+}
+
+#define ch_map_key_clear(c)	hid_map_usage_clear(hi, usage, bit, max, \
+					EV_KEY, (c))
+static int ch_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_MSVENDOR)
+		return 0;
+
+	set_bit(EV_REP, hi->input->evbit);
+	switch (usage->hid & HID_USAGE) {
+	case 0xff01: ch_map_key_clear(BTN_1);	break;
+	case 0xff02: ch_map_key_clear(BTN_2);	break;
+	case 0xff03: ch_map_key_clear(BTN_3);	break;
+	case 0xff04: ch_map_key_clear(BTN_4);	break;
+	case 0xff05: ch_map_key_clear(BTN_5);	break;
+	case 0xff06: ch_map_key_clear(BTN_6);	break;
+	case 0xff07: ch_map_key_clear(BTN_7);	break;
+	case 0xff08: ch_map_key_clear(BTN_8);	break;
+	case 0xff09: ch_map_key_clear(BTN_9);	break;
+	case 0xff0a: ch_map_key_clear(BTN_A);	break;
+	case 0xff0b: ch_map_key_clear(BTN_B);	break;
+	case 0x00f1: ch_map_key_clear(KEY_WLAN);	break;
+	case 0x00f2: ch_map_key_clear(KEY_BRIGHTNESSDOWN);	break;
+	case 0x00f3: ch_map_key_clear(KEY_BRIGHTNESSUP);	break;
+	case 0x00f4: ch_map_key_clear(KEY_DISPLAY_OFF);	break;
+	case 0x00f7: ch_map_key_clear(KEY_CAMERA);	break;
+	case 0x00f8: ch_map_key_clear(KEY_PROG1);	break;
+	default:
+		return 0;
+	}
+	return 1;
+}
+
+static const __u8 *ch_switch12_report_fixup(struct hid_device *hdev,
+		__u8 *rdesc, unsigned int *rsize)
+{
+	struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
+	
+	if (intf->cur_altsetting->desc.bInterfaceNumber == 1) {
+		/* Change usage maximum and logical maximum from 0x7fff to
+		 * 0x2fff, so they don't exceed HID_MAX_USAGES */
+		switch (hdev->product) {
+		case USB_DEVICE_ID_CHICONY_ACER_SWITCH12:
+			if (*rsize >= 128 && rdesc[64] == 0xff && rdesc[65] == 0x7f
+					&& rdesc[69] == 0xff && rdesc[70] == 0x7f) {
+				hid_info(hdev, "Fixing up report descriptor\n");
+				rdesc[65] = rdesc[70] = 0x2f;
+			}
+			break;
+		}
+
+	}
+	return rdesc;
+}
+
+static int ch_probe(struct hid_device *hdev, const struct hid_device_id *id)
+{
+	int ret;
+
+	if (!hid_is_usb(hdev))
+		return -EINVAL;
+
+	hdev->quirks |= HID_QUIRK_INPUT_PER_APP;
+	ret = hid_parse(hdev);
+	if (ret) {
+		hid_err(hdev, "Chicony hid parse failed: %d\n", ret);
+		return ret;
+	}
+
+	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
+	if (ret) {
+		hid_err(hdev, "Chicony hw start failed: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct hid_device_id ch_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_CHICONY, USB_DEVICE_ID_CHICONY_TACTICAL_PAD) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_CHICONY, USB_DEVICE_ID_CHICONY_WIRELESS2) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_CHICONY, USB_DEVICE_ID_CHICONY_WIRELESS3) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_CHICONY, USB_DEVICE_ID_CHICONY_ACER_SWITCH12) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, ch_devices);
+
+static struct hid_driver ch_driver = {
+	.name = "chicony",
+	.id_table = ch_devices,
+	.report_fixup = ch_switch12_report_fixup,
+	.input_mapping = ch_input_mapping,
+	.probe = ch_probe,
+	.raw_event = ch_raw_event,
+};
+module_hid_driver(ch_driver);
+
+MODULE_DESCRIPTION("HID driver for some chicony \"special\" devices");
+MODULE_LICENSE("GPL");