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Validate kernel info

This commit is contained in:
Braiden Vasco 2017-11-04 14:03:45 +00:00
parent 1912698cff
commit 0c8c3cfb2a
4 changed files with 158 additions and 0 deletions

View file

@ -1,5 +1,7 @@
#include <kernelmq/info.h>
static unsigned char cmdline_terminated(const char *s);
unsigned char kernelmq_info_validate_and_copy(
struct KernelMQ_Info *const dest,
const struct KernelMQ_Info *const src
@ -8,7 +10,156 @@ unsigned char kernelmq_info_validate_and_copy(
return 0;
}
if (!cmdline_terminated(src->cmdline)) {
return 0;
}
if (src->modules_count > KERNELMQ_INFO_MODULES_MAX) {
return 0;
}
if (src->areas_count > KERNELMQ_INFO_AREAS_MAX) {
return 0;
}
// TODO: architecture-dependent
if (src->mem_lower_base != KERNELMQ_INFO_MEM_LOWER_BASE) {
return 0;
}
// TODO: architecture-dependent
if (src->mem_upper_base != KERNELMQ_INFO_MEM_UPPER_BASE) {
return 0;
}
// TODO: architecture-dependent
if (src->mem_lower_size == 0) {
return 0;
}
// TODO: architecture-dependent
if (src->mem_upper_size == 0) {
return 0;
}
// TODO: architecture-dependent
if (src->mem_lower_size > KERNELMQ_INFO_MEM_LOWER_SIZE_MAX) {
return 0;
}
if (src->mem_lower_base + src->mem_lower_size != src->mem_lower_limit + 1) {
return 0;
}
if (src->mem_upper_base + src->mem_upper_size != src->mem_upper_limit + 1) {
return 0;
}
if (src->kernel_size == 0) {
return 0;
}
if (src->kernel_offset == 0) {
return 0;
}
if (src->kernel_phys_base + src->kernel_size != src->kernel_phys_limit + 1) {
return 0;
}
if (src->kernel_virt_base + src->kernel_size != src->kernel_virt_limit + 1) {
return 0;
}
if (src->kernel_virt_base - src->kernel_phys_base != src->kernel_offset) {
return 0;
}
unsigned long modules_total_size = 0;
for (unsigned int i = 0; i < src->modules_count; ++i) {
const struct KernelMQ_Info_Module *const module = &src->modules[i];
modules_total_size += module->size;
if (module->size == 0) {
return 0;
}
if (module->base + module->size != module->limit + 1) {
return 0;
}
if (!cmdline_terminated(module->cmdline)) {
return 0;
}
}
if (src->modules_total_size != modules_total_size) {
return 0;
}
if (src->kernel_and_modules_total_size != src->kernel_size + src->modules_total_size) {
return 0;
}
unsigned long long last = 0;
for (unsigned int i = 0; i < src->areas_count; ++i) {
const struct KernelMQ_Info_Area *const area = &src->areas[i];
if (last > area->base) {
return 0;
}
if (area->size == 0) {
return 0;
}
if (area->base + area->size != area->limit + 1) {
return 0;
}
last = area->limit + 1;
if (!area->is_available) {
if (src->kernel_phys_base >= area->base &&
src->kernel_phys_base <= area->limit) {
return 0;
}
if (src->kernel_phys_limit >= area->base &&
src->kernel_phys_limit <= area->limit) {
return 0;
}
for (unsigned int j = 0; j < src->modules_count; ++j) {
const struct KernelMQ_Info_Module *const module = &src->modules[j];
if (module->base >= area->base &&
module->base <= area->limit) {
return 0;
}
if (module->limit >= area->base &&
module->limit <= area->limit) {
return 0;
}
}
}
}
*dest = *src;
return 1;
}
unsigned char cmdline_terminated(const char *const s)
{
for (unsigned int i = 0; i < KERNELMQ_INFO_CMDLINE_SIZE_MAX; ++i) {
if (s[i] == 0) {
return 1;
}
}
return 0;
}

View file

@ -32,5 +32,7 @@ const struct KernelMQ_Info *init(unsigned long multiboot_magic, unsigned long mu
kinfo.kernel_phys_limit = kinfo.kernel_phys_base + kinfo.kernel_size - 1;
kinfo.kernel_virt_limit = kinfo.kernel_virt_base + kinfo.kernel_size - 1;
kinfo.kernel_and_modules_total_size = kinfo.kernel_size + kinfo.modules_total_size;
return &kinfo;
}

View file

@ -149,6 +149,8 @@ unsigned char print_multiboot_tag_module(struct KernelMQ_Info *kinfo, const stru
++kinfo->modules_count;
kinfo->modules_total_size += module->size;
return 1;
}

View file

@ -10,9 +10,12 @@ extern "C" {
#define KERNELMQ_INFO_MODULES_MAX 20
#define KERNELMQ_INFO_AREAS_MAX 20
// TODO: architecture-dependent
#define KERNELMQ_INFO_MEM_LOWER_BASE ((unsigned long)0)
// TODO: architecture-dependent
#define KERNELMQ_INFO_MEM_UPPER_BASE ((unsigned long)(1 * 1024 * 1024 * 1024)) // 1 MB
// TODO: architecture-dependent
#define KERNELMQ_INFO_MEM_LOWER_SIZE_MAX ((unsigned long)(640 * 1024)) // 640 KB
struct KernelMQ_Info_Module {