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, 85 insertions, 0 deletions

diff --git a/drivers/hid/hid-input-test.c b/drivers/hid/hid-input-test.c
new file mode 100644
index 000000000..c92008daf
--- /dev/null
+++ b/drivers/hid/hid-input-test.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  HID to Linux Input mapping
+ *
+ *  Copyright (c) 2022 José Expósito <jose.exposito89@gmail.com>
+ */
+
+#include <kunit/test.h>
+
+static void hid_test_input_update_battery_charge_status(struct kunit *test)
+{
+	struct hid_battery *bat;
+	bool handled;
+
+	bat = kunit_kzalloc(test, sizeof(*bat), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, bat);
+
+	handled = hidinput_update_battery_charge_status(bat, HID_DG_HEIGHT, 0);
+	KUNIT_EXPECT_FALSE(test, handled);
+	KUNIT_EXPECT_EQ(test, bat->charge_status, POWER_SUPPLY_STATUS_UNKNOWN);
+
+	handled = hidinput_update_battery_charge_status(bat, HID_BAT_CHARGING, 0);
+	KUNIT_EXPECT_TRUE(test, handled);
+	KUNIT_EXPECT_EQ(test, bat->charge_status, POWER_SUPPLY_STATUS_DISCHARGING);
+
+	handled = hidinput_update_battery_charge_status(bat, HID_BAT_CHARGING, 1);
+	KUNIT_EXPECT_TRUE(test, handled);
+	KUNIT_EXPECT_EQ(test, bat->charge_status, POWER_SUPPLY_STATUS_CHARGING);
+}
+
+static void hid_test_input_get_battery_property(struct kunit *test)
+{
+	struct power_supply *psy;
+	struct hid_battery *bat;
+	struct hid_device *dev;
+	union power_supply_propval val;
+	int ret;
+
+	dev = kunit_kzalloc(test, sizeof(*dev), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, dev);
+
+	bat = kunit_kzalloc(test, sizeof(*bat), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, bat);
+	bat->dev = dev;
+	bat->avoid_query = true;
+
+	psy = kunit_kzalloc(test, sizeof(*psy), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, psy);
+	psy->drv_data = bat;
+
+	bat->status = HID_BATTERY_UNKNOWN;
+	bat->charge_status = POWER_SUPPLY_STATUS_CHARGING;
+	ret = hidinput_get_battery_property(psy, POWER_SUPPLY_PROP_STATUS, &val);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, val.intval, POWER_SUPPLY_STATUS_UNKNOWN);
+
+	bat->status = HID_BATTERY_REPORTED;
+	bat->charge_status = POWER_SUPPLY_STATUS_CHARGING;
+	ret = hidinput_get_battery_property(psy, POWER_SUPPLY_PROP_STATUS, &val);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, val.intval, POWER_SUPPLY_STATUS_CHARGING);
+
+	bat->status = HID_BATTERY_REPORTED;
+	bat->charge_status = POWER_SUPPLY_STATUS_DISCHARGING;
+	ret = hidinput_get_battery_property(psy, POWER_SUPPLY_PROP_STATUS, &val);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, val.intval, POWER_SUPPLY_STATUS_DISCHARGING);
+}
+
+static struct kunit_case hid_input_tests[] = {
+	KUNIT_CASE(hid_test_input_update_battery_charge_status),
+	KUNIT_CASE(hid_test_input_get_battery_property),
+	{ }
+};
+
+static struct kunit_suite hid_input_test_suite = {
+	.name = "hid_input",
+	.test_cases = hid_input_tests,
+};
+
+kunit_test_suite(hid_input_test_suite);
+
+MODULE_DESCRIPTION("HID input KUnit tests");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("José Expósito <jose.exposito89@gmail.com>");