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/mfd/lp87565.c | 126 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 126 insertions(+) create mode 100644 drivers/mfd/lp87565.c (limited to 'drivers/mfd/lp87565.c') diff --git a/drivers/mfd/lp87565.c b/drivers/mfd/lp87565.c new file mode 100644 index 000000000..b78ae79df --- /dev/null +++ b/drivers/mfd/lp87565.c @@ -0,0 +1,126 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2017 Texas Instruments Incorporated - https://www.ti.com/ + * + * Author: Keerthy + */ + +#include +#include +#include +#include +#include +#include + +#include + +static const struct regmap_config lp87565_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .max_register = LP87565_REG_MAX, +}; + +static const struct mfd_cell lp87565_cells[] = { + { .name = "lp87565-q1-regulator", }, + { .name = "lp87565-q1-gpio", }, +}; + +static const struct of_device_id of_lp87565_match_table[] = { + { .compatible = "ti,lp87565", }, + { + .compatible = "ti,lp87524-q1", + .data = (void *)LP87565_DEVICE_TYPE_LP87524_Q1, + }, + { + .compatible = "ti,lp87565-q1", + .data = (void *)LP87565_DEVICE_TYPE_LP87565_Q1, + }, + { + .compatible = "ti,lp87561-q1", + .data = (void *)LP87565_DEVICE_TYPE_LP87561_Q1, + }, + {} +}; +MODULE_DEVICE_TABLE(of, of_lp87565_match_table); + +static int lp87565_probe(struct i2c_client *client) +{ + struct lp87565 *lp87565; + int ret; + unsigned int otpid; + + lp87565 = devm_kzalloc(&client->dev, sizeof(*lp87565), GFP_KERNEL); + if (!lp87565) + return -ENOMEM; + + lp87565->dev = &client->dev; + + lp87565->regmap = devm_regmap_init_i2c(client, &lp87565_regmap_config); + if (IS_ERR(lp87565->regmap)) { + ret = PTR_ERR(lp87565->regmap); + dev_err(lp87565->dev, + "Failed to initialize register map: %d\n", ret); + return ret; + } + + lp87565->reset_gpio = devm_gpiod_get_optional(lp87565->dev, "reset", + GPIOD_OUT_LOW); + if (IS_ERR(lp87565->reset_gpio)) { + ret = PTR_ERR(lp87565->reset_gpio); + if (ret == -EPROBE_DEFER) + return ret; + } + + if (lp87565->reset_gpio) { + gpiod_set_value_cansleep(lp87565->reset_gpio, 1); + /* The minimum assertion time is undocumented, just guess */ + usleep_range(2000, 4000); + + gpiod_set_value_cansleep(lp87565->reset_gpio, 0); + /* Min 1.2 ms before first I2C transaction */ + usleep_range(1500, 3000); + } + + ret = regmap_read(lp87565->regmap, LP87565_REG_OTP_REV, &otpid); + if (ret) { + dev_err(lp87565->dev, "Failed to read OTP ID\n"); + return ret; + } + + lp87565->rev = otpid & LP87565_OTP_REV_OTP_ID; + lp87565->dev_type = (uintptr_t)i2c_get_match_data(client); + + i2c_set_clientdata(client, lp87565); + + return devm_mfd_add_devices(lp87565->dev, PLATFORM_DEVID_AUTO, + lp87565_cells, ARRAY_SIZE(lp87565_cells), + NULL, 0, NULL); +} + +static void lp87565_shutdown(struct i2c_client *client) +{ + struct lp87565 *lp87565 = i2c_get_clientdata(client); + + gpiod_set_value_cansleep(lp87565->reset_gpio, 1); +} + +static const struct i2c_device_id lp87565_id_table[] = { + { "lp87565-q1" }, + { } +}; +MODULE_DEVICE_TABLE(i2c, lp87565_id_table); + +static struct i2c_driver lp87565_driver = { + .driver = { + .name = "lp87565", + .of_match_table = of_lp87565_match_table, + }, + .probe = lp87565_probe, + .shutdown = lp87565_shutdown, + .id_table = lp87565_id_table, +}; +module_i2c_driver(lp87565_driver); + +MODULE_AUTHOR("J Keerthy "); +MODULE_DESCRIPTION("lp87565 chip family Multi-Function Device driver"); +MODULE_LICENSE("GPL v2"); -- cgit v1.3.1