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, 222 insertions, 0 deletions

diff --git a/drivers/hid/hid-uclogic-params-test.c b/drivers/hid/hid-uclogic-params-test.c
new file mode 100644
index 000000000..a30121419
--- /dev/null
+++ b/drivers/hid/hid-uclogic-params-test.c
@@ -0,0 +1,222 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+/*
+ *  HID driver for UC-Logic devices not fully compliant with HID standard
+ *
+ *  Copyright (c) 2022 José Expósito <jose.exposito89@gmail.com>
+ */
+
+#include <kunit/test.h>
+#include "./hid-uclogic-params.h"
+#include "./hid-uclogic-rdesc.h"
+
+#define MAX_STR_DESC_SIZE 14
+
+struct uclogic_parse_ugee_v2_desc_case {
+	const char *name;
+	int res;
+	const __u8 str_desc[MAX_STR_DESC_SIZE];
+	size_t str_desc_size;
+	const s32 desc_params[UCLOGIC_RDESC_PH_ID_NUM];
+	enum uclogic_params_frame_type frame_type;
+};
+
+static struct uclogic_parse_ugee_v2_desc_case uclogic_parse_ugee_v2_desc_cases[] = {
+	{
+		.name = "invalid_str_desc",
+		.res = -EINVAL,
+		.str_desc = {},
+		.str_desc_size = 0,
+		.desc_params = {},
+		.frame_type = UCLOGIC_PARAMS_FRAME_BUTTONS,
+	},
+	{
+		.name = "resolution_with_value_0",
+		.res = 0,
+		.str_desc = {
+			0x0E, 0x03,
+			0x70, 0xB2,
+			0x10, 0x77,
+			0x08,
+			0x00,
+			0xFF, 0x1F,
+			0x00, 0x00,
+		},
+		.str_desc_size = 12,
+		.desc_params = {
+			[UCLOGIC_RDESC_PEN_PH_ID_X_LM] = 0xB270,
+			[UCLOGIC_RDESC_PEN_PH_ID_X_PM] = 0,
+			[UCLOGIC_RDESC_PEN_PH_ID_Y_LM] = 0x7710,
+			[UCLOGIC_RDESC_PEN_PH_ID_Y_PM] = 0,
+			[UCLOGIC_RDESC_PEN_PH_ID_PRESSURE_LM] = 0x1FFF,
+			[UCLOGIC_RDESC_FRAME_PH_ID_UM] = 0x08,
+		},
+		.frame_type = UCLOGIC_PARAMS_FRAME_BUTTONS,
+	},
+	/* XP-PEN Deco L str_desc: Frame with 8 buttons */
+	{
+		.name = "frame_type_buttons",
+		.res = 0,
+		.str_desc = {
+			0x0E, 0x03,
+			0x70, 0xB2,
+			0x10, 0x77,
+			0x08,
+			0x00,
+			0xFF, 0x1F,
+			0xD8, 0x13,
+		},
+		.str_desc_size = 12,
+		.desc_params = {
+			[UCLOGIC_RDESC_PEN_PH_ID_X_LM] = 0xB270,
+			[UCLOGIC_RDESC_PEN_PH_ID_X_PM] = 0x2320,
+			[UCLOGIC_RDESC_PEN_PH_ID_Y_LM] = 0x7710,
+			[UCLOGIC_RDESC_PEN_PH_ID_Y_PM] = 0x1770,
+			[UCLOGIC_RDESC_PEN_PH_ID_PRESSURE_LM] = 0x1FFF,
+			[UCLOGIC_RDESC_FRAME_PH_ID_UM] = 0x08,
+		},
+		.frame_type = UCLOGIC_PARAMS_FRAME_BUTTONS,
+	},
+	/* PARBLO A610 PRO str_desc: Frame with 9 buttons and dial */
+	{
+		.name = "frame_type_dial",
+		.res = 0,
+		.str_desc = {
+			0x0E, 0x03,
+			0x96, 0xC7,
+			0xF9, 0x7C,
+			0x09,
+			0x01,
+			0xFF, 0x1F,
+			0xD8, 0x13,
+		},
+		.str_desc_size = 12,
+		.desc_params = {
+			[UCLOGIC_RDESC_PEN_PH_ID_X_LM] = 0xC796,
+			[UCLOGIC_RDESC_PEN_PH_ID_X_PM] = 0x2749,
+			[UCLOGIC_RDESC_PEN_PH_ID_Y_LM] = 0x7CF9,
+			[UCLOGIC_RDESC_PEN_PH_ID_Y_PM] = 0x1899,
+			[UCLOGIC_RDESC_PEN_PH_ID_PRESSURE_LM] = 0x1FFF,
+			[UCLOGIC_RDESC_FRAME_PH_ID_UM] = 0x09,
+		},
+		.frame_type = UCLOGIC_PARAMS_FRAME_DIAL,
+	},
+	/* XP-PEN Deco Pro S str_desc: Frame with 8 buttons and mouse */
+	{
+		.name = "frame_type_mouse",
+		.res = 0,
+		.str_desc = {
+			0x0E, 0x03,
+			0xC8, 0xB3,
+			0x34, 0x65,
+			0x08,
+			0x02,
+			0xFF, 0x1F,
+			0xD8, 0x13,
+		},
+		.str_desc_size = 12,
+		.desc_params = {
+			[UCLOGIC_RDESC_PEN_PH_ID_X_LM] = 0xB3C8,
+			[UCLOGIC_RDESC_PEN_PH_ID_X_PM] = 0x2363,
+			[UCLOGIC_RDESC_PEN_PH_ID_Y_LM] = 0x6534,
+			[UCLOGIC_RDESC_PEN_PH_ID_Y_PM] = 0x13EC,
+			[UCLOGIC_RDESC_PEN_PH_ID_PRESSURE_LM] = 0x1FFF,
+			[UCLOGIC_RDESC_FRAME_PH_ID_UM] = 0x08,
+		},
+		.frame_type = UCLOGIC_PARAMS_FRAME_MOUSE,
+	},
+};
+
+static void uclogic_parse_ugee_v2_desc_case_desc(struct uclogic_parse_ugee_v2_desc_case *t,
+						 char *desc)
+{
+	strscpy(desc, t->name, KUNIT_PARAM_DESC_SIZE);
+}
+
+KUNIT_ARRAY_PARAM(uclogic_parse_ugee_v2_desc, uclogic_parse_ugee_v2_desc_cases,
+		  uclogic_parse_ugee_v2_desc_case_desc);
+
+static void hid_test_uclogic_parse_ugee_v2_desc(struct kunit *test)
+{
+	int res;
+	s32 desc_params[UCLOGIC_RDESC_PH_ID_NUM];
+	enum uclogic_params_frame_type frame_type;
+	const struct uclogic_parse_ugee_v2_desc_case *params = test->param_value;
+
+	res = uclogic_params_parse_ugee_v2_desc(params->str_desc,
+						params->str_desc_size,
+						desc_params,
+						ARRAY_SIZE(desc_params),
+						&frame_type);
+	KUNIT_ASSERT_EQ(test, res, params->res);
+
+	if (res)
+		return;
+
+	KUNIT_EXPECT_EQ(test,
+			params->desc_params[UCLOGIC_RDESC_PEN_PH_ID_X_LM],
+			desc_params[UCLOGIC_RDESC_PEN_PH_ID_X_LM]);
+	KUNIT_EXPECT_EQ(test,
+			params->desc_params[UCLOGIC_RDESC_PEN_PH_ID_X_PM],
+			desc_params[UCLOGIC_RDESC_PEN_PH_ID_X_PM]);
+	KUNIT_EXPECT_EQ(test,
+			params->desc_params[UCLOGIC_RDESC_PEN_PH_ID_Y_LM],
+			desc_params[UCLOGIC_RDESC_PEN_PH_ID_Y_LM]);
+	KUNIT_EXPECT_EQ(test,
+			params->desc_params[UCLOGIC_RDESC_PEN_PH_ID_Y_PM],
+			desc_params[UCLOGIC_RDESC_PEN_PH_ID_Y_PM]);
+	KUNIT_EXPECT_EQ(test,
+			params->desc_params[UCLOGIC_RDESC_PEN_PH_ID_PRESSURE_LM],
+			desc_params[UCLOGIC_RDESC_PEN_PH_ID_PRESSURE_LM]);
+	KUNIT_EXPECT_EQ(test,
+			params->desc_params[UCLOGIC_RDESC_FRAME_PH_ID_UM],
+			desc_params[UCLOGIC_RDESC_FRAME_PH_ID_UM]);
+	KUNIT_EXPECT_EQ(test, params->frame_type, frame_type);
+}
+
+struct fake_device {
+	unsigned long quirks;
+};
+
+static void hid_test_uclogic_params_cleanup_event_hooks(struct kunit *test)
+{
+	int res, n;
+	struct hid_device *hdev;
+	struct fake_device *fake_dev;
+	struct uclogic_params p = {0, };
+
+	hdev = kunit_kzalloc(test, sizeof(struct hid_device), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, hdev);
+
+	fake_dev = kunit_kzalloc(test, sizeof(struct fake_device), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, fake_dev);
+
+	hid_set_drvdata(hdev, fake_dev);
+
+	res = uclogic_params_ugee_v2_init_event_hooks(hdev, &p);
+	KUNIT_ASSERT_EQ(test, res, 0);
+
+	/* Check that the function can be called repeatedly */
+	for (n = 0; n < 4; n++) {
+		uclogic_params_cleanup_event_hooks(&p);
+		KUNIT_EXPECT_PTR_EQ(test, p.event_hooks, NULL);
+	}
+}
+
+static struct kunit_case hid_uclogic_params_test_cases[] = {
+	KUNIT_CASE_PARAM(hid_test_uclogic_parse_ugee_v2_desc,
+			 uclogic_parse_ugee_v2_desc_gen_params),
+	KUNIT_CASE(hid_test_uclogic_params_cleanup_event_hooks),
+	{}
+};
+
+static struct kunit_suite hid_uclogic_params_test_suite = {
+	.name = "hid_uclogic_params_test",
+	.test_cases = hid_uclogic_params_test_cases,
+};
+
+kunit_test_suite(hid_uclogic_params_test_suite);
+
+MODULE_DESCRIPTION("KUnit tests for the UC-Logic driver");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("José Expósito <jose.exposito89@gmail.com>");