From 78004e9a87f240df03e2f73120d291763c32e0a7 Mon Sep 17 00:00:00 2001 From: Ali Ahmet Memis Date: Fri, 21 Aug 2026 01:45:27 +0000 Subject: openrisc: fix arbitrary kernel memory access via or1k_atomic syscall 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 Signed-off-by: Stafford Horne --- drivers/input/touchscreen/ipaq-micro-ts.c | 156 ++++++++++++++++++++++++++++++ 1 file changed, 156 insertions(+) create mode 100644 drivers/input/touchscreen/ipaq-micro-ts.c (limited to 'drivers/input/touchscreen/ipaq-micro-ts.c') diff --git a/drivers/input/touchscreen/ipaq-micro-ts.c b/drivers/input/touchscreen/ipaq-micro-ts.c new file mode 100644 index 000000000..243e6465d --- /dev/null +++ b/drivers/input/touchscreen/ipaq-micro-ts.c @@ -0,0 +1,156 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * + * h3600 atmel micro companion support, touchscreen subdevice + * Author : Alessandro Gardich + * Author : Dmitry Artamonow + * Author : Linus Walleij + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct touchscreen_data { + struct input_dev *input; + struct ipaq_micro *micro; +}; + +static void micro_ts_receive(void *data, int len, unsigned char *msg) +{ + struct touchscreen_data *ts = data; + + if (len == 4) { + input_report_abs(ts->input, ABS_X, + be16_to_cpup((__be16 *) &msg[2])); + input_report_abs(ts->input, ABS_Y, + be16_to_cpup((__be16 *) &msg[0])); + input_report_key(ts->input, BTN_TOUCH, 1); + input_sync(ts->input); + } else if (len == 0) { + input_report_abs(ts->input, ABS_X, 0); + input_report_abs(ts->input, ABS_Y, 0); + input_report_key(ts->input, BTN_TOUCH, 0); + input_sync(ts->input); + } +} + +static void micro_ts_toggle_receive(struct touchscreen_data *ts, bool enable) +{ + struct ipaq_micro *micro = ts->micro; + + guard(spinlock_irq)(µ->lock); + + if (enable) { + micro->ts = micro_ts_receive; + micro->ts_data = ts; + } else { + micro->ts = NULL; + micro->ts_data = NULL; + } +} + +static int micro_ts_open(struct input_dev *input) +{ + struct touchscreen_data *ts = input_get_drvdata(input); + + micro_ts_toggle_receive(ts, true); + + return 0; +} + +static void micro_ts_close(struct input_dev *input) +{ + struct touchscreen_data *ts = input_get_drvdata(input); + + micro_ts_toggle_receive(ts, false); +} + +static int micro_ts_probe(struct platform_device *pdev) +{ + struct ipaq_micro *micro = dev_get_drvdata(pdev->dev.parent); + struct touchscreen_data *ts; + int error; + + ts = devm_kzalloc(&pdev->dev, sizeof(*ts), GFP_KERNEL); + if (!ts) + return -ENOMEM; + + ts->micro = micro; + + ts->input = devm_input_allocate_device(&pdev->dev); + if (!ts->input) { + dev_err(&pdev->dev, "failed to allocate input device\n"); + return -ENOMEM; + } + + ts->input->name = "ipaq micro ts"; + ts->input->open = micro_ts_open; + ts->input->close = micro_ts_close; + + input_set_drvdata(ts->input, ts); + + input_set_capability(ts->input, EV_KEY, BTN_TOUCH); + input_set_capability(ts->input, EV_ABS, ABS_X); + input_set_capability(ts->input, EV_ABS, ABS_Y); + input_set_abs_params(ts->input, ABS_X, 0, 1023, 0, 0); + input_set_abs_params(ts->input, ABS_Y, 0, 1023, 0, 0); + + error = input_register_device(ts->input); + if (error) { + dev_err(&pdev->dev, "error registering touch input\n"); + return error; + } + + platform_set_drvdata(pdev, ts); + + dev_info(&pdev->dev, "iPAQ micro touchscreen\n"); + + return 0; +} + +static int micro_ts_suspend(struct device *dev) +{ + struct touchscreen_data *ts = dev_get_drvdata(dev); + + micro_ts_toggle_receive(ts, false); + + return 0; +} + +static int micro_ts_resume(struct device *dev) +{ + struct touchscreen_data *ts = dev_get_drvdata(dev); + struct input_dev *input = ts->input; + + guard(mutex)(&input->mutex); + + if (input_device_enabled(input)) + micro_ts_toggle_receive(ts, true); + + return 0; +} + +static DEFINE_SIMPLE_DEV_PM_OPS(micro_ts_dev_pm_ops, + micro_ts_suspend, micro_ts_resume); + +static struct platform_driver micro_ts_device_driver = { + .driver = { + .name = "ipaq-micro-ts", + .pm = pm_sleep_ptr(µ_ts_dev_pm_ops), + }, + .probe = micro_ts_probe, +}; +module_platform_driver(micro_ts_device_driver); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("driver for iPAQ Atmel micro touchscreen"); +MODULE_ALIAS("platform:ipaq-micro-ts"); -- cgit v1.3.1