Revision 8ec7791bae1327b1c279c5cd6e929c3b12daaf0a authored by Michael Ellerman on 06 May 2021, 04:49:58 UTC, committed by Michael Ellerman on 14 May 2021, 07:27:36 UTC
The STF (store-to-load forwarding) barrier mitigation can be
enabled/disabled at runtime via a debugfs file (stf_barrier), which
causes the kernel to patch itself to enable/disable the relevant
mitigations.
However depending on which mitigation we're using, it may not be safe to
do that patching while other CPUs are active. For example the following
crash:
User access of kernel address (c00000003fff5af0) - exploit attempt? (uid: 0)
segfault (11) at c00000003fff5af0 nip 7fff8ad12198 lr 7fff8ad121f8 code 1
code: 40820128 e93c00d0 e9290058 7c292840 40810058 38600000 4bfd9a81 e8410018
code: 2c030006 41810154 3860ffb6 e9210098 <e94d8ff0> 7d295279 39400000 40820a3c
Shows that we returned to userspace without restoring the user r13
value, due to executing the partially patched STF exit code.
Fix it by doing the patching under stop machine. The CPUs that aren't
doing the patching will be spinning in the core of the stop machine
logic. That is currently sufficient for our purposes, because none of
the patching we do is to that code or anywhere in the vicinity.
Fixes: a048a07d7f45 ("powerpc/64s: Add support for a store forwarding barrier at kernel entry/exit")
Cc: stable@vger.kernel.org # v4.17+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210506044959.1298123-1-mpe@ellerman.id.au
1 parent da3bb20
ecrdsa_defs.h
/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Definitions of EC-RDSA Curve Parameters
*
* Copyright (c) 2019 Vitaly Chikunov <vt@altlinux.org>
*
* 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.
*/
#ifndef _CRYTO_ECRDSA_DEFS_H
#define _CRYTO_ECRDSA_DEFS_H
#include "ecc.h"
#define ECRDSA_MAX_SIG_SIZE (2 * 512 / 8)
#define ECRDSA_MAX_DIGITS (512 / 64)
/*
* EC-RDSA uses its own set of curves.
*
* cp256{a,b,c} curves first defined for GOST R 34.10-2001 in RFC 4357 (as
* 256-bit {A,B,C}-ParamSet), but inherited for GOST R 34.10-2012 and
* proposed for use in R 50.1.114-2016 and RFC 7836 as the 256-bit curves.
*/
/* OID_gostCPSignA 1.2.643.2.2.35.1 */
static u64 cp256a_g_x[] = {
0x0000000000000001ull, 0x0000000000000000ull,
0x0000000000000000ull, 0x0000000000000000ull, };
static u64 cp256a_g_y[] = {
0x22ACC99C9E9F1E14ull, 0x35294F2DDF23E3B1ull,
0x27DF505A453F2B76ull, 0x8D91E471E0989CDAull, };
static u64 cp256a_p[] = { /* p = 2^256 - 617 */
0xFFFFFFFFFFFFFD97ull, 0xFFFFFFFFFFFFFFFFull,
0xFFFFFFFFFFFFFFFFull, 0xFFFFFFFFFFFFFFFFull };
static u64 cp256a_n[] = {
0x45841B09B761B893ull, 0x6C611070995AD100ull,
0xFFFFFFFFFFFFFFFFull, 0xFFFFFFFFFFFFFFFFull };
static u64 cp256a_a[] = { /* a = p - 3 */
0xFFFFFFFFFFFFFD94ull, 0xFFFFFFFFFFFFFFFFull,
0xFFFFFFFFFFFFFFFFull, 0xFFFFFFFFFFFFFFFFull };
static u64 cp256a_b[] = {
0x00000000000000a6ull, 0x0000000000000000ull,
0x0000000000000000ull, 0x0000000000000000ull };
static struct ecc_curve gost_cp256a = {
.name = "cp256a",
.g = {
.x = cp256a_g_x,
.y = cp256a_g_y,
.ndigits = 256 / 64,
},
.p = cp256a_p,
.n = cp256a_n,
.a = cp256a_a,
.b = cp256a_b
};
/* OID_gostCPSignB 1.2.643.2.2.35.2 */
static u64 cp256b_g_x[] = {
0x0000000000000001ull, 0x0000000000000000ull,
0x0000000000000000ull, 0x0000000000000000ull, };
static u64 cp256b_g_y[] = {
0x744BF8D717717EFCull, 0xC545C9858D03ECFBull,
0xB83D1C3EB2C070E5ull, 0x3FA8124359F96680ull, };
static u64 cp256b_p[] = { /* p = 2^255 + 3225 */
0x0000000000000C99ull, 0x0000000000000000ull,
0x0000000000000000ull, 0x8000000000000000ull, };
static u64 cp256b_n[] = {
0xE497161BCC8A198Full, 0x5F700CFFF1A624E5ull,
0x0000000000000001ull, 0x8000000000000000ull, };
static u64 cp256b_a[] = { /* a = p - 3 */
0x0000000000000C96ull, 0x0000000000000000ull,
0x0000000000000000ull, 0x8000000000000000ull, };
static u64 cp256b_b[] = {
0x2F49D4CE7E1BBC8Bull, 0xE979259373FF2B18ull,
0x66A7D3C25C3DF80Aull, 0x3E1AF419A269A5F8ull, };
static struct ecc_curve gost_cp256b = {
.name = "cp256b",
.g = {
.x = cp256b_g_x,
.y = cp256b_g_y,
.ndigits = 256 / 64,
},
.p = cp256b_p,
.n = cp256b_n,
.a = cp256b_a,
.b = cp256b_b
};
/* OID_gostCPSignC 1.2.643.2.2.35.3 */
static u64 cp256c_g_x[] = {
0x0000000000000000ull, 0x0000000000000000ull,
0x0000000000000000ull, 0x0000000000000000ull, };
static u64 cp256c_g_y[] = {
0x366E550DFDB3BB67ull, 0x4D4DC440D4641A8Full,
0x3CBF3783CD08C0EEull, 0x41ECE55743711A8Cull, };
static u64 cp256c_p[] = {
0x7998F7B9022D759Bull, 0xCF846E86789051D3ull,
0xAB1EC85E6B41C8AAull, 0x9B9F605F5A858107ull,
/* pre-computed value for Barrett's reduction */
0xedc283cdd217b5a2ull, 0xbac48fc06398ae59ull,
0x405384d55f9f3b73ull, 0xa51f176161f1d734ull,
0x0000000000000001ull, };
static u64 cp256c_n[] = {
0xF02F3A6598980BB9ull, 0x582CA3511EDDFB74ull,
0xAB1EC85E6B41C8AAull, 0x9B9F605F5A858107ull, };
static u64 cp256c_a[] = { /* a = p - 3 */
0x7998F7B9022D7598ull, 0xCF846E86789051D3ull,
0xAB1EC85E6B41C8AAull, 0x9B9F605F5A858107ull, };
static u64 cp256c_b[] = {
0x000000000000805aull, 0x0000000000000000ull,
0x0000000000000000ull, 0x0000000000000000ull, };
static struct ecc_curve gost_cp256c = {
.name = "cp256c",
.g = {
.x = cp256c_g_x,
.y = cp256c_g_y,
.ndigits = 256 / 64,
},
.p = cp256c_p,
.n = cp256c_n,
.a = cp256c_a,
.b = cp256c_b
};
/* tc512{a,b} curves first recommended in 2013 and then standardized in
* R 50.1.114-2016 and RFC 7836 for use with GOST R 34.10-2012 (as TC26
* 512-bit ParamSet{A,B}).
*/
/* OID_gostTC26Sign512A 1.2.643.7.1.2.1.2.1 */
static u64 tc512a_g_x[] = {
0x0000000000000003ull, 0x0000000000000000ull,
0x0000000000000000ull, 0x0000000000000000ull,
0x0000000000000000ull, 0x0000000000000000ull,
0x0000000000000000ull, 0x0000000000000000ull, };
static u64 tc512a_g_y[] = {
0x89A589CB5215F2A4ull, 0x8028FE5FC235F5B8ull,
0x3D75E6A50E3A41E9ull, 0xDF1626BE4FD036E9ull,
0x778064FDCBEFA921ull, 0xCE5E1C93ACF1ABC1ull,
0xA61B8816E25450E6ull, 0x7503CFE87A836AE3ull, };
static u64 tc512a_p[] = { /* p = 2^512 - 569 */
0xFFFFFFFFFFFFFDC7ull, 0xFFFFFFFFFFFFFFFFull,
0xFFFFFFFFFFFFFFFFull, 0xFFFFFFFFFFFFFFFFull,
0xFFFFFFFFFFFFFFFFull, 0xFFFFFFFFFFFFFFFFull,
0xFFFFFFFFFFFFFFFFull, 0xFFFFFFFFFFFFFFFFull, };
static u64 tc512a_n[] = {
0xCACDB1411F10B275ull, 0x9B4B38ABFAD2B85Dull,
0x6FF22B8D4E056060ull, 0x27E69532F48D8911ull,
0xFFFFFFFFFFFFFFFFull, 0xFFFFFFFFFFFFFFFFull,
0xFFFFFFFFFFFFFFFFull, 0xFFFFFFFFFFFFFFFFull, };
static u64 tc512a_a[] = { /* a = p - 3 */
0xFFFFFFFFFFFFFDC4ull, 0xFFFFFFFFFFFFFFFFull,
0xFFFFFFFFFFFFFFFFull, 0xFFFFFFFFFFFFFFFFull,
0xFFFFFFFFFFFFFFFFull, 0xFFFFFFFFFFFFFFFFull,
0xFFFFFFFFFFFFFFFFull, 0xFFFFFFFFFFFFFFFFull, };
static u64 tc512a_b[] = {
0x503190785A71C760ull, 0x862EF9D4EBEE4761ull,
0x4CB4574010DA90DDull, 0xEE3CB090F30D2761ull,
0x79BD081CFD0B6265ull, 0x34B82574761CB0E8ull,
0xC1BD0B2B6667F1DAull, 0xE8C2505DEDFC86DDull, };
static struct ecc_curve gost_tc512a = {
.name = "tc512a",
.g = {
.x = tc512a_g_x,
.y = tc512a_g_y,
.ndigits = 512 / 64,
},
.p = tc512a_p,
.n = tc512a_n,
.a = tc512a_a,
.b = tc512a_b
};
/* OID_gostTC26Sign512B 1.2.643.7.1.2.1.2.2 */
static u64 tc512b_g_x[] = {
0x0000000000000002ull, 0x0000000000000000ull,
0x0000000000000000ull, 0x0000000000000000ull,
0x0000000000000000ull, 0x0000000000000000ull,
0x0000000000000000ull, 0x0000000000000000ull, };
static u64 tc512b_g_y[] = {
0x7E21340780FE41BDull, 0x28041055F94CEEECull,
0x152CBCAAF8C03988ull, 0xDCB228FD1EDF4A39ull,
0xBE6DD9E6C8EC7335ull, 0x3C123B697578C213ull,
0x2C071E3647A8940Full, 0x1A8F7EDA389B094Cull, };
static u64 tc512b_p[] = { /* p = 2^511 + 111 */
0x000000000000006Full, 0x0000000000000000ull,
0x0000000000000000ull, 0x0000000000000000ull,
0x0000000000000000ull, 0x0000000000000000ull,
0x0000000000000000ull, 0x8000000000000000ull, };
static u64 tc512b_n[] = {
0xC6346C54374F25BDull, 0x8B996712101BEA0Eull,
0xACFDB77BD9D40CFAull, 0x49A1EC142565A545ull,
0x0000000000000001ull, 0x0000000000000000ull,
0x0000000000000000ull, 0x8000000000000000ull, };
static u64 tc512b_a[] = { /* a = p - 3 */
0x000000000000006Cull, 0x0000000000000000ull,
0x0000000000000000ull, 0x0000000000000000ull,
0x0000000000000000ull, 0x0000000000000000ull,
0x0000000000000000ull, 0x8000000000000000ull, };
static u64 tc512b_b[] = {
0xFB8CCBC7C5140116ull, 0x50F78BEE1FA3106Eull,
0x7F8B276FAD1AB69Cull, 0x3E965D2DB1416D21ull,
0xBF85DC806C4B289Full, 0xB97C7D614AF138BCull,
0x7E3E06CF6F5E2517ull, 0x687D1B459DC84145ull, };
static struct ecc_curve gost_tc512b = {
.name = "tc512b",
.g = {
.x = tc512b_g_x,
.y = tc512b_g_y,
.ndigits = 512 / 64,
},
.p = tc512b_p,
.n = tc512b_n,
.a = tc512b_a,
.b = tc512b_b
};
#endif
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