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/thunderbolt/configfs.c | 61 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) create mode 100644 drivers/thunderbolt/configfs.c (limited to 'drivers/thunderbolt/configfs.c') diff --git a/drivers/thunderbolt/configfs.c b/drivers/thunderbolt/configfs.c new file mode 100644 index 000000000..dc6bc363d --- /dev/null +++ b/drivers/thunderbolt/configfs.c @@ -0,0 +1,61 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * ConfigFS support + * + * Copyright (C) 2026, Intel Corporation + * Author: Mika Westerberg + */ + +#include +#include + +#include "tb.h" + +static const struct config_item_type tb_root_group_type = { + .ct_owner = THIS_MODULE, +}; + +static struct configfs_subsystem tb_configfs = { + .su_group = { + .cg_item = { + .ci_namebuf = "thunderbolt", + .ci_type = &tb_root_group_type, + }, + }, +}; + +/** + * tb_configfs_register_group() - Register Thunderbolt ConfigFS group + * @group: Group to register. + * + * Registers the new @group under Thunderbolt subsystem ConfigFS. + * + * Return: 0% in case of success, negative errno otherwise. + */ +int tb_configfs_register_group(struct config_group *group) +{ + return configfs_register_group(&tb_configfs.su_group, group); +} +EXPORT_SYMBOL_GPL(tb_configfs_register_group); + +/** + * tb_configfs_unregister_group() - Unregister previously registered group + * @group: Group to unregister. + */ +void tb_configfs_unregister_group(struct config_group *group) +{ + configfs_unregister_group(group); +} +EXPORT_SYMBOL_GPL(tb_configfs_unregister_group); + +int tb_configfs_init(void) +{ + config_group_init(&tb_configfs.su_group); + mutex_init(&tb_configfs.su_mutex); + return configfs_register_subsystem(&tb_configfs); +} + +void tb_configfs_exit(void) +{ + configfs_unregister_subsystem(&tb_configfs); +} -- cgit v1.3.1