linux/security/lsm_syscalls.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* System calls implementing the Linux Security Module API.
*
* Copyright (C) 2022 Casey Schaufler <casey@schaufler-ca.com>
* Copyright (C) 2022 Intel Corporation
*/
#include <asm/current.h>
#include <linux/compiler_types.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/security.h>
#include <linux/stddef.h>
#include <linux/syscalls.h>
#include <linux/types.h>
#include <linux/lsm_hooks.h>
#include <uapi/linux/lsm.h>
/**
* lsm_name_to_attr - map an LSM attribute name to its ID
* @name: name of the attribute
*
* Returns the LSM attribute value associated with @name, or 0 if
* there is no mapping.
*/
u64 lsm_name_to_attr(const char *name)
{
if (!strcmp(name, "current"))
return LSM_ATTR_CURRENT;
if (!strcmp(name, "exec"))
return LSM_ATTR_EXEC;
if (!strcmp(name, "fscreate"))
return LSM_ATTR_FSCREATE;
if (!strcmp(name, "keycreate"))
return LSM_ATTR_KEYCREATE;
if (!strcmp(name, "prev"))
return LSM_ATTR_PREV;
if (!strcmp(name, "sockcreate"))
return LSM_ATTR_SOCKCREATE;
return LSM_ATTR_UNDEF;
}
/**
* sys_lsm_set_self_attr - Set current task's security module attribute
* @attr: which attribute to set
* @ctx: the LSM contexts
* @size: size of @ctx
* @flags: reserved for future use
*
* Sets the calling task's LSM context. On success this function
* returns 0. If the attribute specified cannot be set a negative
* value indicating the reason for the error is returned.
*/
SYSCALL_DEFINE4(lsm_set_self_attr, unsigned int, attr, struct lsm_ctx __user *,
ctx, size_t, size, u32, flags)
{
return security_setselfattr(attr, ctx, size, flags);
}
/**
* sys_lsm_get_self_attr - Return current task's security module attributes
* @attr: which attribute to return
* @ctx: the user-space destination for the information, or NULL
* @size: pointer to the size of space available to receive the data
* @flags: special handling options. LSM_FLAG_SINGLE indicates that only
* attributes associated with the LSM identified in the passed @ctx be
* reported.
*
* Returns the calling task's LSM contexts. On success this
* function returns the number of @ctx array elements. This value
* may be zero if there are no LSM contexts assigned. If @size is
* insufficient to contain the return data -E2BIG is returned and
* @size is set to the minimum required size. In all other cases
* a negative value indicating the error is returned.
*/
SYSCALL_DEFINE4(lsm_get_self_attr, unsigned int, attr, struct lsm_ctx __user *,
ctx, size_t __user *, size, u32, flags)
{
return security_getselfattr(attr, ctx, size, flags);
}
/**
* sys_lsm_list_modules - Return a list of the active security modules
* @ids: the LSM module ids
* @size: pointer to size of @ids, updated on return
* @flags: reserved for future use, must be zero
*
* Returns a list of the active LSM ids. On success this function
* returns the number of @ids array elements. This value may be zero
* if there are no LSMs active. If @size is insufficient to contain
* the return data -E2BIG is returned and @size is set to the minimum
* required size. In all other cases a negative value indicating the
* error is returned.
*/
SYSCALL_DEFINE3(lsm_list_modules, u64 __user *, ids, size_t __user *, size,
u32, flags)
{
size_t total_size = lsm_active_cnt * sizeof(*ids);
size_t usize;
int i;
if (flags)
return -EINVAL;
if (get_user(usize, size))
return -EFAULT;
if (put_user(total_size, size) != 0)
return -EFAULT;
if (usize < total_size)
return -E2BIG;
for (i = 0; i < lsm_active_cnt; i++)
if (put_user(lsm_idlist[i]->id, ids++))
return -EFAULT;
return lsm_active_cnt;
}