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/mp2629.c | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 79 insertions(+) create mode 100644 drivers/mfd/mp2629.c (limited to 'drivers/mfd/mp2629.c') diff --git a/drivers/mfd/mp2629.c b/drivers/mfd/mp2629.c new file mode 100644 index 000000000..717b704c3 --- /dev/null +++ b/drivers/mfd/mp2629.c @@ -0,0 +1,79 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * MP2629 parent driver for ADC and battery charger + * + * Copyright 2020 Monolithic Power Systems, Inc + * + * Author: Saravanan Sekar + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +static const struct mfd_cell mp2629_cell[] = { + { + .name = "mp2629_adc", + .of_compatible = "mps,mp2629_adc", + }, + { + .name = "mp2629_charger", + .of_compatible = "mps,mp2629_charger", + } +}; + +static const struct regmap_config mp2629_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .max_register = 0x17, +}; + +static int mp2629_probe(struct i2c_client *client) +{ + struct mp2629_data *ddata; + int ret; + + ddata = devm_kzalloc(&client->dev, sizeof(*ddata), GFP_KERNEL); + if (!ddata) + return -ENOMEM; + + ddata->dev = &client->dev; + i2c_set_clientdata(client, ddata); + + ddata->regmap = devm_regmap_init_i2c(client, &mp2629_regmap_config); + if (IS_ERR(ddata->regmap)) { + dev_err(ddata->dev, "Failed to allocate regmap\n"); + return PTR_ERR(ddata->regmap); + } + + ret = devm_mfd_add_devices(ddata->dev, PLATFORM_DEVID_AUTO, mp2629_cell, + ARRAY_SIZE(mp2629_cell), NULL, 0, NULL); + if (ret) + dev_err(ddata->dev, "Failed to register sub-devices %d\n", ret); + + return ret; +} + +static const struct of_device_id mp2629_of_match[] = { + { .compatible = "mps,mp2629"}, + { } +}; +MODULE_DEVICE_TABLE(of, mp2629_of_match); + +static struct i2c_driver mp2629_driver = { + .driver = { + .name = "mp2629", + .of_match_table = mp2629_of_match, + }, + .probe = mp2629_probe, +}; +module_i2c_driver(mp2629_driver); + +MODULE_AUTHOR("Saravanan Sekar "); +MODULE_DESCRIPTION("MP2629 Battery charger parent driver"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1