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/lp873x.c | 87 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 87 insertions(+) create mode 100644 drivers/mfd/lp873x.c (limited to 'drivers/mfd/lp873x.c') diff --git a/drivers/mfd/lp873x.c b/drivers/mfd/lp873x.c new file mode 100644 index 000000000..d2c90302b --- /dev/null +++ b/drivers/mfd/lp873x.c @@ -0,0 +1,87 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2016 Texas Instruments Incorporated - https://www.ti.com/ + * + * Author: Keerthy + */ + +#include +#include +#include +#include + +#include + +static const struct regmap_config lp873x_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .max_register = LP873X_REG_MAX, +}; + +static const struct mfd_cell lp873x_cells[] = { + { .name = "lp873x-regulator", }, + { .name = "lp873x-gpio", }, +}; + +static int lp873x_probe(struct i2c_client *client) +{ + struct lp873x *lp873; + int ret; + unsigned int otpid; + + lp873 = devm_kzalloc(&client->dev, sizeof(*lp873), GFP_KERNEL); + if (!lp873) + return -ENOMEM; + + lp873->dev = &client->dev; + + lp873->regmap = devm_regmap_init_i2c(client, &lp873x_regmap_config); + if (IS_ERR(lp873->regmap)) { + ret = PTR_ERR(lp873->regmap); + dev_err(lp873->dev, + "Failed to initialize register map: %d\n", ret); + return ret; + } + + ret = regmap_read(lp873->regmap, LP873X_REG_OTP_REV, &otpid); + if (ret) { + dev_err(lp873->dev, "Failed to read OTP ID\n"); + return ret; + } + + lp873->rev = otpid & LP873X_OTP_REV_OTP_ID; + + i2c_set_clientdata(client, lp873); + + ret = mfd_add_devices(lp873->dev, PLATFORM_DEVID_AUTO, lp873x_cells, + ARRAY_SIZE(lp873x_cells), NULL, 0, NULL); + + return ret; +} + +static const struct of_device_id of_lp873x_match_table[] = { + { .compatible = "ti,lp8733", }, + { .compatible = "ti,lp8732", }, + {} +}; +MODULE_DEVICE_TABLE(of, of_lp873x_match_table); + +static const struct i2c_device_id lp873x_id_table[] = { + { "lp873x" }, + { } +}; +MODULE_DEVICE_TABLE(i2c, lp873x_id_table); + +static struct i2c_driver lp873x_driver = { + .driver = { + .name = "lp873x", + .of_match_table = of_lp873x_match_table, + }, + .probe = lp873x_probe, + .id_table = lp873x_id_table, +}; +module_i2c_driver(lp873x_driver); + +MODULE_AUTHOR("J Keerthy "); +MODULE_DESCRIPTION("LP873X chip family Multi-Function Device driver"); +MODULE_LICENSE("GPL v2"); -- cgit v1.3.1