81 lines
2.1 KiB
C
81 lines
2.1 KiB
C
|
// SPDX-License-Identifier: GPL-2.0-or-later
|
||
|
|
/*
|
||
|
|
* Module strict rwx
|
||
|
|
*
|
||
|
|
* Copyright (C) 2015 Rusty Russell
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <linux/module.h>
|
||
|
|
#include <linux/mm.h>
|
||
|
|
#include <linux/vmalloc.h>
|
||
|
|
#include <linux/set_memory.h>
|
||
|
|
#include "internal.h"
|
||
|
|
|
||
|
|
static void module_set_memory(const struct module *mod, enum mod_mem_type type,
|
||
|
|
int (*set_memory)(unsigned long start, int num_pages))
|
||
|
|
{
|
||
|
|
const struct module_memory *mod_mem = &mod->mem[type];
|
||
|
|
|
||
|
|
set_vm_flush_reset_perms(mod_mem->base);
|
||
|
|
set_memory((unsigned long)mod_mem->base, mod_mem->size >> PAGE_SHIFT);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Since some arches are moving towards PAGE_KERNEL module allocations instead
|
||
|
|
* of PAGE_KERNEL_EXEC, keep module_enable_x() independent of
|
||
|
|
* CONFIG_STRICT_MODULE_RWX because they are needed regardless of whether we
|
||
|
|
* are strict.
|
||
|
|
*/
|
||
|
|
void module_enable_x(const struct module *mod)
|
||
|
|
{
|
||
|
|
for_class_mod_mem_type(type, text)
|
||
|
|
module_set_memory(mod, type, set_memory_x);
|
||
|
|
}
|
||
|
|
|
||
|
|
void module_enable_ro(const struct module *mod, bool after_init)
|
||
|
|
{
|
||
|
|
if (!IS_ENABLED(CONFIG_STRICT_MODULE_RWX))
|
||
|
|
return;
|
||
|
|
#ifdef CONFIG_STRICT_MODULE_RWX
|
||
|
|
if (!rodata_enabled)
|
||
|
|
return;
|
||
|
|
#endif
|
||
|
|
|
||
|
|
module_set_memory(mod, MOD_TEXT, set_memory_ro);
|
||
|
|
module_set_memory(mod, MOD_INIT_TEXT, set_memory_ro);
|
||
|
|
module_set_memory(mod, MOD_RODATA, set_memory_ro);
|
||
|
|
module_set_memory(mod, MOD_INIT_RODATA, set_memory_ro);
|
||
|
|
|
||
|
|
if (after_init)
|
||
|
|
module_set_memory(mod, MOD_RO_AFTER_INIT, set_memory_ro);
|
||
|
|
}
|
||
|
|
|
||
|
|
void module_enable_nx(const struct module *mod)
|
||
|
|
{
|
||
|
|
if (!IS_ENABLED(CONFIG_STRICT_MODULE_RWX))
|
||
|
|
return;
|
||
|
|
|
||
|
|
for_class_mod_mem_type(type, data)
|
||
|
|
module_set_memory(mod, type, set_memory_nx);
|
||
|
|
}
|
||
|
|
|
||
|
|
int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
|
||
|
|
char *secstrings, struct module *mod)
|
||
|
|
{
|
||
|
|
const unsigned long shf_wx = SHF_WRITE | SHF_EXECINSTR;
|
||
|
|
int i;
|
||
|
|
|
||
|
|
if (!IS_ENABLED(CONFIG_STRICT_MODULE_RWX))
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
for (i = 0; i < hdr->e_shnum; i++) {
|
||
|
|
if ((sechdrs[i].sh_flags & shf_wx) == shf_wx) {
|
||
|
|
pr_err("%s: section %s (index %d) has invalid WRITE|EXEC flags\n",
|
||
|
|
mod->name, secstrings + sechdrs[i].sh_name, i);
|
||
|
|
return -ENOEXEC;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|