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, 170 insertions, 0 deletions

diff --git a/drivers/hid/hid-mf.c b/drivers/hid/hid-mf.c
new file mode 100644
index 000000000..6ff54a1ec
--- /dev/null
+++ b/drivers/hid/hid-mf.c
@@ -0,0 +1,170 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Force feedback support for Mayflash game controller adapters.
+ *
+ * These devices are manufactured by Mayflash but identify themselves
+ * using the vendor ID of DragonRise Inc.
+ *
+ * Tested with:
+ * 0079:1801 "DragonRise Inc. Mayflash PS3 Game Controller Adapter"
+ * 0079:1803 "DragonRise Inc. Mayflash Wireless Sensor DolphinBar"
+ * 0079:1843 "DragonRise Inc. Mayflash GameCube Game Controller Adapter"
+ * 0079:1844 "DragonRise Inc. Mayflash GameCube Game Controller Adapter (v04)"
+ *
+ * The following adapters probably work too, but need to be tested:
+ * 0079:1800 "DragonRise Inc. Mayflash WIIU Game Controller Adapter"
+ *
+ * Copyright (c) 2016-2017 Marcel Hasler <mahasler@gmail.com>
+ */
+
+/*
+ */
+
+#include <linux/input.h>
+#include <linux/slab.h>
+#include <linux/hid.h>
+#include <linux/module.h>
+
+#include "hid-ids.h"
+
+struct mf_device {
+	struct hid_report *report;
+};
+
+static int mf_play(struct input_dev *dev, void *data, struct ff_effect *effect)
+{
+	struct hid_device *hid = input_get_drvdata(dev);
+	struct mf_device *mf = data;
+	int strong, weak;
+
+	strong = effect->u.rumble.strong_magnitude;
+	weak = effect->u.rumble.weak_magnitude;
+
+	dbg_hid("Called with 0x%04x 0x%04x.\n", strong, weak);
+
+	strong = strong * 0xff / 0xffff;
+	weak = weak * 0xff / 0xffff;
+
+	dbg_hid("Running with 0x%02x 0x%02x.\n", strong, weak);
+
+	mf->report->field[0]->value[0] = weak;
+	mf->report->field[0]->value[1] = strong;
+	hid_hw_request(hid, mf->report, HID_REQ_SET_REPORT);
+
+	return 0;
+}
+
+static int mf_init(struct hid_device *hid)
+{
+	struct mf_device *mf;
+
+	struct list_head *report_list =
+			&hid->report_enum[HID_OUTPUT_REPORT].report_list;
+
+	struct list_head *report_ptr;
+	struct hid_report *report;
+
+	struct list_head *input_ptr = &hid->inputs;
+	struct hid_input *input;
+
+	struct input_dev *dev;
+
+	int error;
+
+	/* Setup each of the four inputs */
+	list_for_each(report_ptr, report_list) {
+		report = list_entry(report_ptr, struct hid_report, list);
+
+		if (report->maxfield < 1 || report->field[0]->report_count < 2) {
+			hid_err(hid, "Invalid report, this should never happen!\n");
+			return -ENODEV;
+		}
+
+		if (list_is_last(input_ptr, &hid->inputs)) {
+			hid_err(hid, "Missing input, this should never happen!\n");
+			return -ENODEV;
+		}
+
+		input_ptr = input_ptr->next;
+		input = list_entry(input_ptr, struct hid_input, list);
+
+		mf = kzalloc_obj(struct mf_device);
+		if (!mf)
+			return -ENOMEM;
+
+		dev = input->input;
+		set_bit(FF_RUMBLE, dev->ffbit);
+
+		error = input_ff_create_memless(dev, mf, mf_play);
+		if (error) {
+			kfree(mf);
+			return error;
+		}
+
+		mf->report = report;
+		mf->report->field[0]->value[0] = 0x00;
+		mf->report->field[0]->value[1] = 0x00;
+		hid_hw_request(hid, mf->report, HID_REQ_SET_REPORT);
+	}
+
+	hid_info(hid, "Force feedback for HJZ Mayflash game controller "
+		      "adapters by Marcel Hasler <mahasler@gmail.com>\n");
+
+	return 0;
+}
+
+static int mf_probe(struct hid_device *hid, const struct hid_device_id *id)
+{
+	int error;
+
+	dev_dbg(&hid->dev, "Mayflash HID hardware probe...\n");
+
+	/* Apply quirks as needed */
+	hid->quirks |= id->driver_data;
+
+	error = hid_parse(hid);
+	if (error) {
+		hid_err(hid, "HID parse failed.\n");
+		return error;
+	}
+
+	error = hid_hw_start(hid, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
+	if (error) {
+		hid_err(hid, "HID hw start failed\n");
+		return error;
+	}
+
+	error = mf_init(hid);
+	if (error) {
+		hid_err(hid, "Force feedback init failed.\n");
+		hid_hw_stop(hid);
+		return error;
+	}
+
+	return 0;
+}
+
+static const struct hid_device_id mf_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_DRAGONRISE, USB_DEVICE_ID_DRAGONRISE_PS3),
+		.driver_data = HID_QUIRK_MULTI_INPUT },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_DRAGONRISE, USB_DEVICE_ID_DRAGONRISE_DOLPHINBAR),
+		.driver_data = HID_QUIRK_MULTI_INPUT },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_DRAGONRISE, USB_DEVICE_ID_DRAGONRISE_GAMECUBE1),
+		.driver_data = HID_QUIRK_MULTI_INPUT },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_DRAGONRISE, USB_DEVICE_ID_DRAGONRISE_GAMECUBE2),
+		.driver_data = 0 }, /* No quirk required */
+	{ HID_USB_DEVICE(USB_VENDOR_ID_DRAGONRISE, USB_DEVICE_ID_DRAGONRISE_GAMECUBE3),
+		.driver_data = HID_QUIRK_MULTI_INPUT },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, mf_devices);
+
+static struct hid_driver mf_driver = {
+	.name = "hid_mf",
+	.id_table = mf_devices,
+	.probe = mf_probe,
+};
+module_hid_driver(mf_driver);
+
+MODULE_DESCRIPTION("Force feedback support for Mayflash game controller adapters.");
+MODULE_LICENSE("GPL");