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
sm3_generic.c
/*
* SM3 secure hash, as specified by OSCCA GM/T 0004-2012 SM3 and
* described at https://tools.ietf.org/html/draft-shen-sm3-hash-01
*
* Copyright (C) 2017 ARM Limited or its affiliates.
* Written by Gilad Ben-Yossef <gilad@benyossef.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include <crypto/internal/hash.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/types.h>
#include <crypto/sm3.h>
#include <crypto/sm3_base.h>
#include <linux/bitops.h>
#include <asm/byteorder.h>
#include <asm/unaligned.h>
const u8 sm3_zero_message_hash[SM3_DIGEST_SIZE] = {
0x1A, 0xB2, 0x1D, 0x83, 0x55, 0xCF, 0xA1, 0x7F,
0x8e, 0x61, 0x19, 0x48, 0x31, 0xE8, 0x1A, 0x8F,
0x22, 0xBE, 0xC8, 0xC7, 0x28, 0xFE, 0xFB, 0x74,
0x7E, 0xD0, 0x35, 0xEB, 0x50, 0x82, 0xAA, 0x2B
};
EXPORT_SYMBOL_GPL(sm3_zero_message_hash);
static inline u32 p0(u32 x)
{
return x ^ rol32(x, 9) ^ rol32(x, 17);
}
static inline u32 p1(u32 x)
{
return x ^ rol32(x, 15) ^ rol32(x, 23);
}
static inline u32 ff(unsigned int n, u32 a, u32 b, u32 c)
{
return (n < 16) ? (a ^ b ^ c) : ((a & b) | (a & c) | (b & c));
}
static inline u32 gg(unsigned int n, u32 e, u32 f, u32 g)
{
return (n < 16) ? (e ^ f ^ g) : ((e & f) | ((~e) & g));
}
static inline u32 t(unsigned int n)
{
return (n < 16) ? SM3_T1 : SM3_T2;
}
static void sm3_expand(u32 *t, u32 *w, u32 *wt)
{
int i;
unsigned int tmp;
/* load the input */
for (i = 0; i <= 15; i++)
w[i] = get_unaligned_be32((__u32 *)t + i);
for (i = 16; i <= 67; i++) {
tmp = w[i - 16] ^ w[i - 9] ^ rol32(w[i - 3], 15);
w[i] = p1(tmp) ^ (rol32(w[i - 13], 7)) ^ w[i - 6];
}
for (i = 0; i <= 63; i++)
wt[i] = w[i] ^ w[i + 4];
}
static void sm3_compress(u32 *w, u32 *wt, u32 *m)
{
u32 ss1;
u32 ss2;
u32 tt1;
u32 tt2;
u32 a, b, c, d, e, f, g, h;
int i;
a = m[0];
b = m[1];
c = m[2];
d = m[3];
e = m[4];
f = m[5];
g = m[6];
h = m[7];
for (i = 0; i <= 63; i++) {
ss1 = rol32((rol32(a, 12) + e + rol32(t(i), i & 31)), 7);
ss2 = ss1 ^ rol32(a, 12);
tt1 = ff(i, a, b, c) + d + ss2 + *wt;
wt++;
tt2 = gg(i, e, f, g) + h + ss1 + *w;
w++;
d = c;
c = rol32(b, 9);
b = a;
a = tt1;
h = g;
g = rol32(f, 19);
f = e;
e = p0(tt2);
}
m[0] = a ^ m[0];
m[1] = b ^ m[1];
m[2] = c ^ m[2];
m[3] = d ^ m[3];
m[4] = e ^ m[4];
m[5] = f ^ m[5];
m[6] = g ^ m[6];
m[7] = h ^ m[7];
a = b = c = d = e = f = g = h = ss1 = ss2 = tt1 = tt2 = 0;
}
static void sm3_transform(struct sm3_state *sst, u8 const *src)
{
unsigned int w[68];
unsigned int wt[64];
sm3_expand((u32 *)src, w, wt);
sm3_compress(w, wt, sst->state);
memzero_explicit(w, sizeof(w));
memzero_explicit(wt, sizeof(wt));
}
static void sm3_generic_block_fn(struct sm3_state *sst, u8 const *src,
int blocks)
{
while (blocks--) {
sm3_transform(sst, src);
src += SM3_BLOCK_SIZE;
}
}
int crypto_sm3_update(struct shash_desc *desc, const u8 *data,
unsigned int len)
{
return sm3_base_do_update(desc, data, len, sm3_generic_block_fn);
}
EXPORT_SYMBOL(crypto_sm3_update);
static int sm3_final(struct shash_desc *desc, u8 *out)
{
sm3_base_do_finalize(desc, sm3_generic_block_fn);
return sm3_base_finish(desc, out);
}
int crypto_sm3_finup(struct shash_desc *desc, const u8 *data,
unsigned int len, u8 *hash)
{
sm3_base_do_update(desc, data, len, sm3_generic_block_fn);
return sm3_final(desc, hash);
}
EXPORT_SYMBOL(crypto_sm3_finup);
static struct shash_alg sm3_alg = {
.digestsize = SM3_DIGEST_SIZE,
.init = sm3_base_init,
.update = crypto_sm3_update,
.final = sm3_final,
.finup = crypto_sm3_finup,
.descsize = sizeof(struct sm3_state),
.base = {
.cra_name = "sm3",
.cra_driver_name = "sm3-generic",
.cra_blocksize = SM3_BLOCK_SIZE,
.cra_module = THIS_MODULE,
}
};
static int __init sm3_generic_mod_init(void)
{
return crypto_register_shash(&sm3_alg);
}
static void __exit sm3_generic_mod_fini(void)
{
crypto_unregister_shash(&sm3_alg);
}
module_init(sm3_generic_mod_init);
module_exit(sm3_generic_mod_fini);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("SM3 Secure Hash Algorithm");
MODULE_ALIAS_CRYPTO("sm3");
MODULE_ALIAS_CRYPTO("sm3-generic");
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