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/misc/ad714x-i2c.c | 97 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 97 insertions(+) create mode 100644 drivers/input/misc/ad714x-i2c.c (limited to 'drivers/input/misc/ad714x-i2c.c') diff --git a/drivers/input/misc/ad714x-i2c.c b/drivers/input/misc/ad714x-i2c.c new file mode 100644 index 000000000..c3cb56151 --- /dev/null +++ b/drivers/input/misc/ad714x-i2c.c @@ -0,0 +1,97 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * AD714X CapTouch Programmable Controller driver (I2C bus) + * + * Copyright 2009-2011 Analog Devices Inc. + */ + +#include /* BUS_I2C */ +#include +#include +#include +#include +#include "ad714x.h" + +static int ad714x_i2c_write(struct ad714x_chip *chip, + unsigned short reg, unsigned short data) +{ + struct i2c_client *client = to_i2c_client(chip->dev); + int error; + + chip->xfer_buf[0] = cpu_to_be16(reg); + chip->xfer_buf[1] = cpu_to_be16(data); + + error = i2c_master_send(client, (u8 *)chip->xfer_buf, + 2 * sizeof(*chip->xfer_buf)); + if (unlikely(error < 0)) { + dev_err(&client->dev, "I2C write error: %d\n", error); + return error; + } + + return 0; +} + +static int ad714x_i2c_read(struct ad714x_chip *chip, + unsigned short reg, unsigned short *data, size_t len) +{ + struct i2c_client *client = to_i2c_client(chip->dev); + int i; + int error; + + chip->xfer_buf[0] = cpu_to_be16(reg); + + error = i2c_master_send(client, (u8 *)chip->xfer_buf, + sizeof(*chip->xfer_buf)); + if (error >= 0) + error = i2c_master_recv(client, (u8 *)chip->xfer_buf, + len * sizeof(*chip->xfer_buf)); + + if (unlikely(error < 0)) { + dev_err(&client->dev, "I2C read error: %d\n", error); + return error; + } + + for (i = 0; i < len; i++) + data[i] = be16_to_cpu(chip->xfer_buf[i]); + + return 0; +} + +static int ad714x_i2c_probe(struct i2c_client *client) +{ + struct ad714x_chip *chip; + + chip = ad714x_probe(&client->dev, BUS_I2C, client->irq, + ad714x_i2c_read, ad714x_i2c_write); + if (IS_ERR(chip)) + return PTR_ERR(chip); + + i2c_set_clientdata(client, chip); + + return 0; +} + +static const struct i2c_device_id ad714x_id[] = { + { .name = "ad7142_captouch" }, + { .name = "ad7143_captouch" }, + { .name = "ad7147_captouch" }, + { .name = "ad7147a_captouch" }, + { .name = "ad7148_captouch" }, + { } +}; +MODULE_DEVICE_TABLE(i2c, ad714x_id); + +static struct i2c_driver ad714x_i2c_driver = { + .driver = { + .name = "ad714x_captouch", + .pm = pm_sleep_ptr(&ad714x_pm), + }, + .probe = ad714x_i2c_probe, + .id_table = ad714x_id, +}; + +module_i2c_driver(ad714x_i2c_driver); + +MODULE_DESCRIPTION("Analog Devices AD714X Capacitance Touch Sensor I2C Bus Driver"); +MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1