Revision ec3937107ab43f3e8b2bc9dad95710043c462ff7 authored by Baoquan He on 04 April 2019, 02:03:13 UTC, committed by Borislav Petkov on 18 April 2019, 08:42:58 UTC
kernel_randomize_memory() uses __PHYSICAL_MASK_SHIFT to calculate the maximum amount of system RAM supported. The size of the direct mapping section is obtained from the smaller one of the below two values: (actual system RAM size + padding size) vs (max system RAM size supported) This calculation is wrong since commit b83ce5ee9147 ("x86/mm/64: Make __PHYSICAL_MASK_SHIFT always 52"). In it, __PHYSICAL_MASK_SHIFT was changed to be 52, regardless of whether the kernel is using 4-level or 5-level page tables. Thus, it will always use 4 PB as the maximum amount of system RAM, even in 4-level paging mode where it should actually be 64 TB. Thus, the size of the direct mapping section will always be the sum of the actual system RAM size plus the padding size. Even when the amount of system RAM is 64 TB, the following layout will still be used. Obviously KALSR will be weakened significantly. |____|_______actual RAM_______|_padding_|______the rest_______| 0 64TB ~120TB Instead, it should be like this: |____|_______actual RAM_______|_________the rest______________| 0 64TB ~120TB The size of padding region is controlled by CONFIG_RANDOMIZE_MEMORY_PHYSICAL_PADDING, which is 10 TB by default. The above issue only exists when CONFIG_RANDOMIZE_MEMORY_PHYSICAL_PADDING is set to a non-zero value, which is the case when CONFIG_MEMORY_HOTPLUG is enabled. Otherwise, using __PHYSICAL_MASK_SHIFT doesn't affect KASLR. Fix it by replacing __PHYSICAL_MASK_SHIFT with MAX_PHYSMEM_BITS. [ bp: Massage commit message. ] Fixes: b83ce5ee9147 ("x86/mm/64: Make __PHYSICAL_MASK_SHIFT always 52") Signed-off-by: Baoquan He <bhe@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Thomas Garnier <thgarnie@google.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: frank.ramsay@hpe.com Cc: herbert@gondor.apana.org.au Cc: kirill@shutemov.name Cc: mike.travis@hpe.com Cc: thgarnie@google.com Cc: x86-ml <x86@kernel.org> Cc: yamada.masahiro@socionext.com Link: https://lkml.kernel.org/r/20190417083536.GE7065@MiWiFi-R3L-srv
1 parent a943245
tea.c
/*
* Cryptographic API.
*
* TEA, XTEA, and XETA crypto alogrithms
*
* The TEA and Xtended TEA algorithms were developed by David Wheeler
* and Roger Needham at the Computer Laboratory of Cambridge University.
*
* Due to the order of evaluation in XTEA many people have incorrectly
* implemented it. XETA (XTEA in the wrong order), exists for
* compatibility with these implementations.
*
* Copyright (c) 2004 Aaron Grothe ajgrothe@yahoo.com
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <asm/byteorder.h>
#include <linux/crypto.h>
#include <linux/types.h>
#define TEA_KEY_SIZE 16
#define TEA_BLOCK_SIZE 8
#define TEA_ROUNDS 32
#define TEA_DELTA 0x9e3779b9
#define XTEA_KEY_SIZE 16
#define XTEA_BLOCK_SIZE 8
#define XTEA_ROUNDS 32
#define XTEA_DELTA 0x9e3779b9
struct tea_ctx {
u32 KEY[4];
};
struct xtea_ctx {
u32 KEY[4];
};
static int tea_setkey(struct crypto_tfm *tfm, const u8 *in_key,
unsigned int key_len)
{
struct tea_ctx *ctx = crypto_tfm_ctx(tfm);
const __le32 *key = (const __le32 *)in_key;
ctx->KEY[0] = le32_to_cpu(key[0]);
ctx->KEY[1] = le32_to_cpu(key[1]);
ctx->KEY[2] = le32_to_cpu(key[2]);
ctx->KEY[3] = le32_to_cpu(key[3]);
return 0;
}
static void tea_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
{
u32 y, z, n, sum = 0;
u32 k0, k1, k2, k3;
struct tea_ctx *ctx = crypto_tfm_ctx(tfm);
const __le32 *in = (const __le32 *)src;
__le32 *out = (__le32 *)dst;
y = le32_to_cpu(in[0]);
z = le32_to_cpu(in[1]);
k0 = ctx->KEY[0];
k1 = ctx->KEY[1];
k2 = ctx->KEY[2];
k3 = ctx->KEY[3];
n = TEA_ROUNDS;
while (n-- > 0) {
sum += TEA_DELTA;
y += ((z << 4) + k0) ^ (z + sum) ^ ((z >> 5) + k1);
z += ((y << 4) + k2) ^ (y + sum) ^ ((y >> 5) + k3);
}
out[0] = cpu_to_le32(y);
out[1] = cpu_to_le32(z);
}
static void tea_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
{
u32 y, z, n, sum;
u32 k0, k1, k2, k3;
struct tea_ctx *ctx = crypto_tfm_ctx(tfm);
const __le32 *in = (const __le32 *)src;
__le32 *out = (__le32 *)dst;
y = le32_to_cpu(in[0]);
z = le32_to_cpu(in[1]);
k0 = ctx->KEY[0];
k1 = ctx->KEY[1];
k2 = ctx->KEY[2];
k3 = ctx->KEY[3];
sum = TEA_DELTA << 5;
n = TEA_ROUNDS;
while (n-- > 0) {
z -= ((y << 4) + k2) ^ (y + sum) ^ ((y >> 5) + k3);
y -= ((z << 4) + k0) ^ (z + sum) ^ ((z >> 5) + k1);
sum -= TEA_DELTA;
}
out[0] = cpu_to_le32(y);
out[1] = cpu_to_le32(z);
}
static int xtea_setkey(struct crypto_tfm *tfm, const u8 *in_key,
unsigned int key_len)
{
struct xtea_ctx *ctx = crypto_tfm_ctx(tfm);
const __le32 *key = (const __le32 *)in_key;
ctx->KEY[0] = le32_to_cpu(key[0]);
ctx->KEY[1] = le32_to_cpu(key[1]);
ctx->KEY[2] = le32_to_cpu(key[2]);
ctx->KEY[3] = le32_to_cpu(key[3]);
return 0;
}
static void xtea_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
{
u32 y, z, sum = 0;
u32 limit = XTEA_DELTA * XTEA_ROUNDS;
struct xtea_ctx *ctx = crypto_tfm_ctx(tfm);
const __le32 *in = (const __le32 *)src;
__le32 *out = (__le32 *)dst;
y = le32_to_cpu(in[0]);
z = le32_to_cpu(in[1]);
while (sum != limit) {
y += ((z << 4 ^ z >> 5) + z) ^ (sum + ctx->KEY[sum&3]);
sum += XTEA_DELTA;
z += ((y << 4 ^ y >> 5) + y) ^ (sum + ctx->KEY[sum>>11 &3]);
}
out[0] = cpu_to_le32(y);
out[1] = cpu_to_le32(z);
}
static void xtea_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
{
u32 y, z, sum;
struct tea_ctx *ctx = crypto_tfm_ctx(tfm);
const __le32 *in = (const __le32 *)src;
__le32 *out = (__le32 *)dst;
y = le32_to_cpu(in[0]);
z = le32_to_cpu(in[1]);
sum = XTEA_DELTA * XTEA_ROUNDS;
while (sum) {
z -= ((y << 4 ^ y >> 5) + y) ^ (sum + ctx->KEY[sum>>11 & 3]);
sum -= XTEA_DELTA;
y -= ((z << 4 ^ z >> 5) + z) ^ (sum + ctx->KEY[sum & 3]);
}
out[0] = cpu_to_le32(y);
out[1] = cpu_to_le32(z);
}
static void xeta_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
{
u32 y, z, sum = 0;
u32 limit = XTEA_DELTA * XTEA_ROUNDS;
struct xtea_ctx *ctx = crypto_tfm_ctx(tfm);
const __le32 *in = (const __le32 *)src;
__le32 *out = (__le32 *)dst;
y = le32_to_cpu(in[0]);
z = le32_to_cpu(in[1]);
while (sum != limit) {
y += (z << 4 ^ z >> 5) + (z ^ sum) + ctx->KEY[sum&3];
sum += XTEA_DELTA;
z += (y << 4 ^ y >> 5) + (y ^ sum) + ctx->KEY[sum>>11 &3];
}
out[0] = cpu_to_le32(y);
out[1] = cpu_to_le32(z);
}
static void xeta_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
{
u32 y, z, sum;
struct tea_ctx *ctx = crypto_tfm_ctx(tfm);
const __le32 *in = (const __le32 *)src;
__le32 *out = (__le32 *)dst;
y = le32_to_cpu(in[0]);
z = le32_to_cpu(in[1]);
sum = XTEA_DELTA * XTEA_ROUNDS;
while (sum) {
z -= (y << 4 ^ y >> 5) + (y ^ sum) + ctx->KEY[sum>>11 & 3];
sum -= XTEA_DELTA;
y -= (z << 4 ^ z >> 5) + (z ^ sum) + ctx->KEY[sum & 3];
}
out[0] = cpu_to_le32(y);
out[1] = cpu_to_le32(z);
}
static struct crypto_alg tea_algs[3] = { {
.cra_name = "tea",
.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
.cra_blocksize = TEA_BLOCK_SIZE,
.cra_ctxsize = sizeof (struct tea_ctx),
.cra_alignmask = 3,
.cra_module = THIS_MODULE,
.cra_u = { .cipher = {
.cia_min_keysize = TEA_KEY_SIZE,
.cia_max_keysize = TEA_KEY_SIZE,
.cia_setkey = tea_setkey,
.cia_encrypt = tea_encrypt,
.cia_decrypt = tea_decrypt } }
}, {
.cra_name = "xtea",
.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
.cra_blocksize = XTEA_BLOCK_SIZE,
.cra_ctxsize = sizeof (struct xtea_ctx),
.cra_alignmask = 3,
.cra_module = THIS_MODULE,
.cra_u = { .cipher = {
.cia_min_keysize = XTEA_KEY_SIZE,
.cia_max_keysize = XTEA_KEY_SIZE,
.cia_setkey = xtea_setkey,
.cia_encrypt = xtea_encrypt,
.cia_decrypt = xtea_decrypt } }
}, {
.cra_name = "xeta",
.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
.cra_blocksize = XTEA_BLOCK_SIZE,
.cra_ctxsize = sizeof (struct xtea_ctx),
.cra_alignmask = 3,
.cra_module = THIS_MODULE,
.cra_u = { .cipher = {
.cia_min_keysize = XTEA_KEY_SIZE,
.cia_max_keysize = XTEA_KEY_SIZE,
.cia_setkey = xtea_setkey,
.cia_encrypt = xeta_encrypt,
.cia_decrypt = xeta_decrypt } }
} };
static int __init tea_mod_init(void)
{
return crypto_register_algs(tea_algs, ARRAY_SIZE(tea_algs));
}
static void __exit tea_mod_fini(void)
{
crypto_unregister_algs(tea_algs, ARRAY_SIZE(tea_algs));
}
MODULE_ALIAS_CRYPTO("tea");
MODULE_ALIAS_CRYPTO("xtea");
MODULE_ALIAS_CRYPTO("xeta");
module_init(tea_mod_init);
module_exit(tea_mod_fini);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("TEA, XTEA & XETA Cryptographic Algorithms");
![swh spinner](/static/img/swh-spinner.gif)
Computing file changes ...