Commit Graph

96 Commits

Author SHA1 Message Date
Hongbo Li
b6f756726e lib/mpi: use kcalloc in mpi_resize
We should set the additional space to 0 in mpi_resize().
So use kcalloc() instead of kmalloc_array().

In lib/mpi/ec.c:
/****************
 * Resize the array of A to NLIMBS. the additional space is cleared
 * (set to 0) [done by m_realloc()]
 */
int mpi_resize(MPI a, unsigned nlimbs)

Like the comment of kernel's mpi_resize() said, the additional space
need to be set to 0, but when a->d is not NULL, it does not set.

The kernel's mpi lib is from libgcrypt, the mpi resize in libgcrypt
is _gcry_mpi_resize() which set the additional space to 0.

This bug may cause mpi api which use mpi_resize() get wrong result
under the condition of using the additional space without initiation.
If this condition is not met, the bug would not be triggered.
Currently in kernel, rsa, sm2 and dh use mpi lib, and they works well,
so the bug is not triggered in these cases.

add_points_edwards() use the additional space directly, so it will
get a wrong result.

Fixes: cdec9cb516 ("crypto: GnuPG based MPI lib - source files (part 1)")
Signed-off-by: Hongbo Li <herberthbli@tencent.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2021-08-12 19:17:00 +08:00
Zhen Lei
478485f6c0 lib/mpi: fix spelling mistakes
Fix some spelling mistakes in comments:
flaged ==> flagged
bufer ==> buffer
multipler ==> multiplier
MULTIPLER ==> MULTIPLIER
leaset ==> least
chnage ==> change

Link: https://lkml.kernel.org/r/20210604074401.12198-1-thunder.leizhen@huawei.com
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:05 -07:00
Herbert Xu
d722869432 lib/mpi: Remove unused scalar_copied
The scalar_copied variable is not as the scalar is never copied
in that block.  This patch removes it.

Fixes: d58bb7e55a ("lib/mpi: Introduce ec implementation to...")
Reported-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-10-30 17:34:45 +11:00
Randy Dunlap
8d8472cfde lib/mpi/mpi-bit.c: fix spello of "functions"
Fix typo/spello of "functions".

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/8df15173-a6df-9426-7cad-a2d279bf1170@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-16 11:11:20 -07:00
Herbert Xu
ae6ee6ae2b lib/mpi: Fix unused variable warnings
This patch removes a number of unused variables and marks others
as unused in order to silence compiler warnings about them.

Fixes: a8ea8bdd9d ("lib/mpi: Extend the MPI library")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Tested-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-10-02 18:02:13 +10:00
Tianjia Zhang
d58bb7e55a lib/mpi: Introduce ec implementation to MPI library
The implementation of EC is introduced from libgcrypt as the
basic algorithm of elliptic curve, which can be more perfectly
integrated with MPI implementation.
Some other algorithms will be developed based on mpi ecc, such as SM2.

Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Tested-by: Xufeng Zhang <yunbo.xufeng@linux.alibaba.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-09-25 17:48:54 +10:00
Tianjia Zhang
a8ea8bdd9d lib/mpi: Extend the MPI library
Expand the mpi library based on libgcrypt, and the ECC algorithm of
mpi based on libgcrypt requires these functions.
Some other algorithms will be developed based on mpi ecc, such as SM2.

Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Tested-by: Xufeng Zhang <yunbo.xufeng@linux.alibaba.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-09-25 17:48:53 +10:00
Waiman Long
453431a549 mm, treewide: rename kzfree() to kfree_sensitive()
As said by Linus:

  A symmetric naming is only helpful if it implies symmetries in use.
  Otherwise it's actively misleading.

  In "kzalloc()", the z is meaningful and an important part of what the
  caller wants.

  In "kzfree()", the z is actively detrimental, because maybe in the
  future we really _might_ want to use that "memfill(0xdeadbeef)" or
  something. The "zero" part of the interface isn't even _relevant_.

The main reason that kzfree() exists is to clear sensitive information
that should not be leaked to other future users of the same memory
objects.

Rename kzfree() to kfree_sensitive() to follow the example of the recently
added kvfree_sensitive() and make the intention of the API more explicit.
In addition, memzero_explicit() is used to clear the memory to make sure
that it won't get optimized away by the compiler.

The renaming is done by using the command sequence:

  git grep -w --name-only kzfree |\
  xargs sed -i 's/kzfree/kfree_sensitive/'

followed by some editing of the kfree_sensitive() kerneldoc and adding
a kzfree backward compatibility macro in slab.h.

[akpm@linux-foundation.org: fs/crypto/inline_crypt.c needs linux/slab.h]
[akpm@linux-foundation.org: fix fs/crypto/inline_crypt.c some more]

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Joe Perches <joe@perches.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "Jason A . Donenfeld" <Jason@zx2c4.com>
Link: http://lkml.kernel.org/r/20200616154311.12314-3-longman@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07 11:33:22 -07:00
Marcelo Henrique Cerri
4278e9d99e lib/mpi: Add mpi_sub_ui()
Add mpi_sub_ui() based on Gnu MP mpz_sub_ui() function from file
mpz/aors_ui.h[1] from change id 510b83519d1c adapting the code to the
kernel's data structures, helper functions and coding style and also
removing the defines used to produce mpz_sub_ui() and mpz_add_ui()
from the same code.

[1] https://gmplib.org/repo/gmp-6.2/file/510b83519d1c/mpz/aors.h

Signed-off-by: Marcelo Henrique Cerri <marcelo.cerri@canonical.com>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-07-31 18:08:59 +10:00
Linus Torvalds
81e8c10dac Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto updates from Herbert Xu:
 "API:
   - Introduce crypto_shash_tfm_digest() and use it wherever possible.
   - Fix use-after-free and race in crypto_spawn_alg.
   - Add support for parallel and batch requests to crypto_engine.

  Algorithms:
   - Update jitter RNG for SP800-90B compliance.
   - Always use jitter RNG as seed in drbg.

  Drivers:
   - Add Arm CryptoCell driver cctrng.
   - Add support for SEV-ES to the PSP driver in ccp"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (114 commits)
  crypto: hisilicon - fix driver compatibility issue with different versions of devices
  crypto: engine - do not requeue in case of fatal error
  crypto: cavium/nitrox - Fix a typo in a comment
  crypto: hisilicon/qm - change debugfs file name from qm_regs to regs
  crypto: hisilicon/qm - add DebugFS for xQC and xQE dump
  crypto: hisilicon/zip - add debugfs for Hisilicon ZIP
  crypto: hisilicon/hpre - add debugfs for Hisilicon HPRE
  crypto: hisilicon/sec2 - add debugfs for Hisilicon SEC
  crypto: hisilicon/qm - add debugfs to the QM state machine
  crypto: hisilicon/qm - add debugfs for QM
  crypto: stm32/crc32 - protect from concurrent accesses
  crypto: stm32/crc32 - don't sleep in runtime pm
  crypto: stm32/crc32 - fix multi-instance
  crypto: stm32/crc32 - fix run-time self test issue.
  crypto: stm32/crc32 - fix ext4 chksum BUG_ON()
  crypto: hisilicon/zip - Use temporary sqe when doing work
  crypto: hisilicon - add device error report through abnormal irq
  crypto: hisilicon - remove codes of directly report device errors through MSI
  crypto: hisilicon - QM memory management optimization
  crypto: hisilicon - unify initial value assignment into QM
  ...
2020-06-01 12:00:10 -07:00
Nathan Chancellor
18f1ca4685 lib/mpi: Fix 64-bit MIPS build with Clang
When building 64r6_defconfig with CONFIG_MIPS32_O32 disabled and
CONFIG_CRYPTO_RSA enabled:

lib/mpi/generic_mpih-mul1.c:37:24: error: invalid use of a cast in a
inline asm context requiring an l-value: remove the cast
or build with -fheinous-gnu-extensions
                umul_ppmm(prod_high, prod_low, s1_ptr[j], s2_limb);
                ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
lib/mpi/longlong.h:664:22: note: expanded from macro 'umul_ppmm'
                 : "=d" ((UDItype)(w0))
                         ~~~~~~~~~~^~~
lib/mpi/generic_mpih-mul1.c:37:13: error: invalid use of a cast in a
inline asm context requiring an l-value: remove the cast
or build with -fheinous-gnu-extensions
                umul_ppmm(prod_high, prod_low, s1_ptr[j], s2_limb);
                ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
lib/mpi/longlong.h:668:22: note: expanded from macro 'umul_ppmm'
                 : "=d" ((UDItype)(w1))
                         ~~~~~~~~~~^~~
2 errors generated.

This special case for umul_ppmm for MIPS64r6 was added in
commit bbc25bee37 ("lib/mpi: Fix umul_ppmm() for MIPS64r6"), due to
GCC being inefficient and emitting a __multi3 intrinsic.

There is no such issue with clang; with this patch applied, I can build
this configuration without any problems and there are no link errors
like mentioned in the commit above (which I can still reproduce with
GCC 9.3.0 when that commit is reverted). Only use this definition when
GCC is being used.

This really should have been caught by commit b0c091ae04 ("lib/mpi:
Eliminate unused umul_ppmm definitions for MIPS") when I was messing
around in this area but I was not testing 64-bit MIPS at the time.

Link: https://github.com/ClangBuiltLinux/linux/issues/885
Reported-by: Dmitry Golovin <dima@golovin.in>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-04-30 15:19:33 +10:00
Nathan Chancellor
5990cdee68 lib/mpi: Fix building for powerpc with clang
0day reports over and over on an powerpc randconfig with clang:

lib/mpi/generic_mpih-mul1.c:37:13: error: invalid use of a cast in a
inline asm context requiring an l-value: remove the cast or build with
-fheinous-gnu-extensions

Remove the superfluous casts, which have been done previously for x86
and arm32 in commit dea632cadd ("lib/mpi: fix build with clang") and
commit 7b7c1df288 ("lib/mpi/longlong.h: fix building with 32-bit
x86").

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://github.com/ClangBuiltLinux/linux/issues/991
Link: https://lore.kernel.org/r/20200413195041.24064-1-natechancellor@gmail.com
2020-04-24 13:14:59 +10:00
Nathan Chancellor
b0c091ae04 lib/mpi: Eliminate unused umul_ppmm definitions for MIPS
Clang errors out when building this macro:

lib/mpi/generic_mpih-mul1.c:37:24: error: invalid use of a cast in a
inline asm context requiring an l-value: remove the cast or build with
-fheinous-gnu-extensions
                umul_ppmm(prod_high, prod_low, s1_ptr[j], s2_limb);
                ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
lib/mpi/longlong.h:652:20: note: expanded from macro 'umul_ppmm'
        : "=l" ((USItype)(w0)), \
                ~~~~~~~~~~^~~
lib/mpi/generic_mpih-mul1.c:37:3: error: invalid output constraint '=h'
in asm
                umul_ppmm(prod_high, prod_low, s1_ptr[j], s2_limb);
                ^
lib/mpi/longlong.h:653:7: note: expanded from macro 'umul_ppmm'
             "=h" ((USItype)(w1)) \
             ^
2 errors generated.

The C version that is used for GCC 4.4 and up works well with clang;
however, it is not currently being used because Clang masks itself
as GCC 4.2.1 for compatibility reasons. As Nick points out, we require
GCC 4.6 and newer in the kernel so we can eliminate all of the
versioning checks and just use the C version of umul_ppmm for all
supported compilers.

Link: https://github.com/ClangBuiltLinux/linux/issues/605
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-08-22 14:39:36 +10:00
Arnd Bergmann
7b7c1df288 lib/mpi/longlong.h: fix building with 32-bit x86
The mpi library contains some rather old inline assembly statements that
produce a lot of warnings for 32-bit x86, such as:

  lib/mpi/mpih-div.c:76:16: error: invalid use of a cast in a inline asm context requiring an l-value: remove the cast or build with -fheinous-gnu-extensions
                                  udiv_qrnnd(qp[i], n1, n1, np[i], d);
                                  ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
  lib/mpi/longlong.h:423:20: note: expanded from macro 'udiv_qrnnd'
          : "=a" ((USItype)(q)), \
                  ~~~~~~~~~~^~

There is no point in doing a type cast for the output of an inline
assembler statement, so just remove the cast here, as we have done for
other architectures in the past.

See also dea632cadd ("lib/mpi: fix build with clang").

Link: http://lkml.kernel.org/r/20190712090740.340186-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-16 19:23:21 -07:00
Linus Torvalds
ee39d46dca Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto fixes from Herbert Xu:
 "This fixes two memory leaks and a list corruption bug"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: user - prevent operating on larval algorithms
  crypto: cryptd - Fix skcipher instance memory leak
  lib/mpi: Fix karactx leak in mpi_powm
2019-07-05 13:31:19 +09:00
Herbert Xu
c8ea9fce2b lib/mpi: Fix karactx leak in mpi_powm
Sometimes mpi_powm will leak karactx because a memory allocation
failure causes a bail-out that skips the freeing of karactx.  This
patch moves the freeing of karactx to the end of the function like
everything else so that it can't be skipped.

Reported-by: syzbot+f7baccc38dcc1e094e77@syzkaller.appspotmail.com
Fixes: cdec9cb516 ("crypto: GnuPG based MPI lib - source files...")
Cc: <stable@vger.kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Reviewed-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-07-03 22:11:55 +08:00
Thomas Gleixner
465ae83692 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 26
Based on 1 normalized pattern(s):

  gnupg 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 gnupg 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 write to the free software foundation inc 59 temple
  place suite 330 boston ma 02111 1307 usa note this code is heavily
  based on the gnu mp library actually it s the same code with only
  minor changes in the way the data is stored this is to support the
  abstraction of an optional secure memory allocation which may be
  used to avoid revealing of sensitive data due to paging etc the gnu
  mp library itself is published under the lgpl however i decided to
  publish this code under the plain gpl

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 14 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190520170856.639982569@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-24 17:27:10 +02:00
Colin Ian King
6122bbbdc6 lib/mpi: remove redundant variable esign
Variable esign is being assigned but is never used hence it is
redundant and can be removed.

Cleans up clang warning:
warning: variable 'esign' set but not used [-Wunused-but-set-variable]

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-08-07 17:51:39 +08:00
Kees Cook
6396bb2215 treewide: kzalloc() -> kcalloc()
The kzalloc() function has a 2-factor argument form, kcalloc(). This
patch replaces cases of:

        kzalloc(a * b, gfp)

with:
        kcalloc(a * b, gfp)

as well as handling cases of:

        kzalloc(a * b * c, gfp)

with:

        kzalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

        kzalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

        kzalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
  kzalloc(
-	(sizeof(TYPE)) * E
+	sizeof(TYPE) * E
  , ...)
|
  kzalloc(
-	(sizeof(THING)) * E
+	sizeof(THING) * E
  , ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
  kzalloc(
-	sizeof(u8) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(__u8) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(char) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(unsigned char) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(u8) * COUNT
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(__u8) * COUNT
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(char) * COUNT
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(unsigned char) * COUNT
+	COUNT
  , ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * (COUNT_ID)
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * COUNT_ID
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * (COUNT_CONST)
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * COUNT_CONST
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * (COUNT_ID)
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * COUNT_ID
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * (COUNT_CONST)
+	COUNT_CONST, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * COUNT_CONST
+	COUNT_CONST, sizeof(THING)
  , ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kzalloc
+ kcalloc
  (
-	SIZE * COUNT
+	COUNT, SIZE
  , ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
  kzalloc(
-	sizeof(TYPE) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(TYPE) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(TYPE) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(TYPE) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(THING) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kzalloc(
-	sizeof(THING) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kzalloc(
-	sizeof(THING) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kzalloc(
-	sizeof(THING) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
  kzalloc(
-	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kzalloc(
-	sizeof(THING1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kzalloc(
-	sizeof(THING1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
|
  kzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
  kzalloc(
-	(COUNT) * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	(COUNT) * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	(COUNT) * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	(COUNT) * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
  kzalloc(C1 * C2 * C3, ...)
|
  kzalloc(
-	(E1) * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kzalloc(
-	(E1) * (E2) * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kzalloc(
-	(E1) * (E2) * (E3)
+	array3_size(E1, E2, E3)
  , ...)
|
  kzalloc(
-	E1 * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
  kzalloc(sizeof(THING) * C2, ...)
|
  kzalloc(sizeof(TYPE) * C2, ...)
|
  kzalloc(C1 * C2 * C3, ...)
|
  kzalloc(C1 * C2, ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * (E2)
+	E2, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * E2
+	E2, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * (E2)
+	E2, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * E2
+	E2, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	(E1) * E2
+	E1, E2
  , ...)
|
- kzalloc
+ kcalloc
  (
-	(E1) * (E2)
+	E1, E2
  , ...)
|
- kzalloc
+ kcalloc
  (
-	E1 * E2
+	E1, E2
  , ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-12 16:19:22 -07:00
Kees Cook
6da2ec5605 treewide: kmalloc() -> kmalloc_array()
The kmalloc() function has a 2-factor argument form, kmalloc_array(). This
patch replaces cases of:

        kmalloc(a * b, gfp)

with:
        kmalloc_array(a * b, gfp)

as well as handling cases of:

        kmalloc(a * b * c, gfp)

with:

        kmalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

        kmalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

        kmalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The tools/ directory was manually excluded, since it has its own
implementation of kmalloc().

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
  kmalloc(
-	(sizeof(TYPE)) * E
+	sizeof(TYPE) * E
  , ...)
|
  kmalloc(
-	(sizeof(THING)) * E
+	sizeof(THING) * E
  , ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
  kmalloc(
-	sizeof(u8) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(__u8) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(char) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(unsigned char) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(u8) * COUNT
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(__u8) * COUNT
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(char) * COUNT
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(unsigned char) * COUNT
+	COUNT
  , ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * (COUNT_ID)
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * COUNT_ID
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * (COUNT_CONST)
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * COUNT_CONST
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * (COUNT_ID)
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * COUNT_ID
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * (COUNT_CONST)
+	COUNT_CONST, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * COUNT_CONST
+	COUNT_CONST, sizeof(THING)
  , ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kmalloc
+ kmalloc_array
  (
-	SIZE * COUNT
+	COUNT, SIZE
  , ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
  kmalloc(
-	sizeof(TYPE) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(TYPE) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(TYPE) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(TYPE) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(THING) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kmalloc(
-	sizeof(THING) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kmalloc(
-	sizeof(THING) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kmalloc(
-	sizeof(THING) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
  kmalloc(
-	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kmalloc(
-	sizeof(THING1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kmalloc(
-	sizeof(THING1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
|
  kmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
  kmalloc(
-	(COUNT) * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	COUNT * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	COUNT * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	(COUNT) * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	COUNT * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	(COUNT) * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	(COUNT) * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	COUNT * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
  kmalloc(C1 * C2 * C3, ...)
|
  kmalloc(
-	(E1) * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kmalloc(
-	(E1) * (E2) * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kmalloc(
-	(E1) * (E2) * (E3)
+	array3_size(E1, E2, E3)
  , ...)
|
  kmalloc(
-	E1 * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
  kmalloc(sizeof(THING) * C2, ...)
|
  kmalloc(sizeof(TYPE) * C2, ...)
|
  kmalloc(C1 * C2 * C3, ...)
|
  kmalloc(C1 * C2, ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * (E2)
+	E2, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * E2
+	E2, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * (E2)
+	E2, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * E2
+	E2, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	(E1) * E2
+	E1, E2
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	(E1) * (E2)
+	E1, E2
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	E1 * E2
+	E1, E2
  , ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-12 16:19:22 -07:00
Vasily Averin
cbdc61ae1f lib/mpi: headers cleanup
MPI headers contain definitions for huge number of non-existing
functions.

Most part of these functions was removed in 2012 by Dmitry Kasatkin
 - 7cf4206a99 ("Remove unused code from MPI library")
 - 9e235dcaf4 ("Revert "crypto: GnuPG based MPI lib - additional ...")
 - bc95eeadf5 ("lib/mpi: removed unused functions")
however headers wwere not updated properly.

Also I deleted some unused macros.

Link: http://lkml.kernel.org/r/fb2fc1ef-1185-f0a3-d8d0-173d2f97bbaf@virtuozzo.com
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:39 -07:00
James Hogan
bbc25bee37 lib/mpi: Fix umul_ppmm() for MIPS64r6
Current MIPS64r6 toolchains aren't able to generate efficient
DMULU/DMUHU based code for the C implementation of umul_ppmm(), which
performs an unsigned 64 x 64 bit multiply and returns the upper and
lower 64-bit halves of the 128-bit result. Instead it widens the 64-bit
inputs to 128-bits and emits a __multi3 intrinsic call to perform a 128
x 128 multiply. This is both inefficient, and it results in a link error
since we don't include __multi3 in MIPS linux.

For example commit 90a53e4432 ("cfg80211: implement regdb signature
checking") merged in v4.15-rc1 recently broke the 64r6_defconfig and
64r6el_defconfig builds by indirectly selecting MPILIB. The same build
errors can be reproduced on older kernels by enabling e.g. CRYPTO_RSA:

lib/mpi/generic_mpih-mul1.o: In function `mpihelp_mul_1':
lib/mpi/generic_mpih-mul1.c:50: undefined reference to `__multi3'
lib/mpi/generic_mpih-mul2.o: In function `mpihelp_addmul_1':
lib/mpi/generic_mpih-mul2.c:49: undefined reference to `__multi3'
lib/mpi/generic_mpih-mul3.o: In function `mpihelp_submul_1':
lib/mpi/generic_mpih-mul3.c:49: undefined reference to `__multi3'
lib/mpi/mpih-div.o In function `mpihelp_divrem':
lib/mpi/mpih-div.c:205: undefined reference to `__multi3'
lib/mpi/mpih-div.c:142: undefined reference to `__multi3'

Therefore add an efficient MIPS64r6 implementation of umul_ppmm() using
inline assembly and the DMULU/DMUHU instructions, to prevent __multi3
calls being emitted.

Fixes: 7fd08ca58a ("MIPS: Add build support for the MIPS R6 ISA")
Signed-off-by: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-mips@linux-mips.org
Cc: linux-crypto@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-12-22 19:39:09 +11:00
Linus Torvalds
37dc79565c Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto updates from Herbert Xu:
 "Here is the crypto update for 4.15:

  API:

   - Disambiguate EBUSY when queueing crypto request by adding ENOSPC.
     This change touches code outside the crypto API.
   - Reset settings when empty string is written to rng_current.

  Algorithms:

   - Add OSCCA SM3 secure hash.

  Drivers:

   - Remove old mv_cesa driver (replaced by marvell/cesa).
   - Enable rfc3686/ecb/cfb/ofb AES in crypto4xx.
   - Add ccm/gcm AES in crypto4xx.
   - Add support for BCM7278 in iproc-rng200.
   - Add hash support on Exynos in s5p-sss.
   - Fix fallback-induced error in vmx.
   - Fix output IV in atmel-aes.
   - Fix empty GCM hash in mediatek.

  Others:

   - Fix DoS potential in lib/mpi.
   - Fix potential out-of-order issues with padata"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (162 commits)
  lib/mpi: call cond_resched() from mpi_powm() loop
  crypto: stm32/hash - Fix return issue on update
  crypto: dh - Remove pointless checks for NULL 'p' and 'g'
  crypto: qat - Clean up error handling in qat_dh_set_secret()
  crypto: dh - Don't permit 'key' or 'g' size longer than 'p'
  crypto: dh - Don't permit 'p' to be 0
  crypto: dh - Fix double free of ctx->p
  hwrng: iproc-rng200 - Add support for BCM7278
  dt-bindings: rng: Document BCM7278 RNG200 compatible
  crypto: chcr - Replace _manual_ swap with swap macro
  crypto: marvell - Add a NULL entry at the end of mv_cesa_plat_id_table[]
  hwrng: virtio - Virtio RNG devices need to be re-registered after suspend/resume
  crypto: atmel - remove empty functions
  crypto: ecdh - remove empty exit()
  MAINTAINERS: update maintainer for qat
  crypto: caam - remove unused param of ctx_map_to_sec4_sg()
  crypto: caam - remove unneeded edesc zeroization
  crypto: atmel-aes - Reset the controller before each use
  crypto: atmel-aes - properly set IV after {en,de}crypt
  hwrng: core - Reset user selected rng by writing "" to rng_current
  ...
2017-11-14 10:52:09 -08:00
Eric Biggers
1d9ddde12e lib/mpi: call cond_resched() from mpi_powm() loop
On a non-preemptible kernel, if KEYCTL_DH_COMPUTE is called with the
largest permitted inputs (16384 bits), the kernel spends 10+ seconds
doing modular exponentiation in mpi_powm() without rescheduling.  If all
threads do it, it locks up the system.  Moreover, it can cause
rcu_sched-stall warnings.

Notwithstanding the insanity of doing this calculation in kernel mode
rather than in userspace, fix it by calling cond_resched() as each bit
from the exponent is processed.  It's still noninterruptible, but at
least it's preemptible now.

Do the cond_resched() once per bit rather than once per MPI limb because
each limb might still easily take 100+ milliseconds on slow CPUs.

Cc: <stable@vger.kernel.org> # v4.12+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-11-10 19:20:26 +08:00
Greg Kroah-Hartman
b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00
Herbert Xu
e90c48efde Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Merge the crypto tree to resolve the conflict between the temporary
and long-term fixes in algif_skcipher.
2017-08-22 14:53:32 +08:00
Stephan Mueller
dea3eb8b45 lib/mpi: kunmap after finishing accessing buffer
Using sg_miter_start and sg_miter_next, the buffer of an SG is kmap'ed
to *buff. The current code calls sg_miter_stop (and thus kunmap) on the
SG entry before the last access of *buff.

The patch moves the sg_miter_stop call after the last access to *buff to
ensure that the memory pointed to by *buff is still mapped.

Fixes: 4816c94064 ("lib/mpi: Fix SG miter leak")
Cc: <stable@vger.kernel.org>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-08-22 14:45:01 +08:00
Stefan Agner
dea632cadd lib/mpi: fix build with clang
Use just @ to denote comments which works with gcc and clang.
Otherwise clang reports an escape sequence error:
  error: invalid % escape in inline assembly string

Use %0-%3 as operand references, this avoids:
  error: invalid operand in inline asm: 'umull ${1:r}, ${0:r}, ${2:r}, ${3:r}'

Also remove superfluous casts on output operands to avoid warnings
such as:
  warning: invalid use of a cast in an inline asm context requiring an l-value

Signed-off-by: Stefan Agner <stefan@agner.ch>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-08-17 16:53:31 +08:00
Andrey Ryabinin
f5527fffff mpi: Fix NULL ptr dereference in mpi_powm() [ver #3]
This fixes CVE-2016-8650.

If mpi_powm() is given a zero exponent, it wants to immediately return
either 1 or 0, depending on the modulus.  However, if the result was
initalised with zero limb space, no limbs space is allocated and a
NULL-pointer exception ensues.

Fix this by allocating a minimal amount of limb space for the result when
the 0-exponent case when the result is 1 and not touching the limb space
when the result is 0.

This affects the use of RSA keys and X.509 certificates that carry them.

BUG: unable to handle kernel NULL pointer dereference at           (null)
IP: [<ffffffff8138ce5d>] mpi_powm+0x32/0x7e6
PGD 0
Oops: 0002 [#1] SMP
Modules linked in:
CPU: 3 PID: 3014 Comm: keyctl Not tainted 4.9.0-rc6-fscache+ #278
Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014
task: ffff8804011944c0 task.stack: ffff880401294000
RIP: 0010:[<ffffffff8138ce5d>]  [<ffffffff8138ce5d>] mpi_powm+0x32/0x7e6
RSP: 0018:ffff880401297ad8  EFLAGS: 00010212
RAX: 0000000000000000 RBX: ffff88040868bec0 RCX: ffff88040868bba0
RDX: ffff88040868b260 RSI: ffff88040868bec0 RDI: ffff88040868bee0
RBP: ffff880401297ba8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000047 R11: ffffffff8183b210 R12: 0000000000000000
R13: ffff8804087c7600 R14: 000000000000001f R15: ffff880401297c50
FS:  00007f7a7918c700(0000) GS:ffff88041fb80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000401250000 CR4: 00000000001406e0
Stack:
 ffff88040868bec0 0000000000000020 ffff880401297b00 ffffffff81376cd4
 0000000000000100 ffff880401297b10 ffffffff81376d12 ffff880401297b30
 ffffffff81376f37 0000000000000100 0000000000000000 ffff880401297ba8
Call Trace:
 [<ffffffff81376cd4>] ? __sg_page_iter_next+0x43/0x66
 [<ffffffff81376d12>] ? sg_miter_get_next_page+0x1b/0x5d
 [<ffffffff81376f37>] ? sg_miter_next+0x17/0xbd
 [<ffffffff8138ba3a>] ? mpi_read_raw_from_sgl+0xf2/0x146
 [<ffffffff8132a95c>] rsa_verify+0x9d/0xee
 [<ffffffff8132acca>] ? pkcs1pad_sg_set_buf+0x2e/0xbb
 [<ffffffff8132af40>] pkcs1pad_verify+0xc0/0xe1
 [<ffffffff8133cb5e>] public_key_verify_signature+0x1b0/0x228
 [<ffffffff8133d974>] x509_check_for_self_signed+0xa1/0xc4
 [<ffffffff8133cdde>] x509_cert_parse+0x167/0x1a1
 [<ffffffff8133d609>] x509_key_preparse+0x21/0x1a1
 [<ffffffff8133c3d7>] asymmetric_key_preparse+0x34/0x61
 [<ffffffff812fc9f3>] key_create_or_update+0x145/0x399
 [<ffffffff812fe227>] SyS_add_key+0x154/0x19e
 [<ffffffff81001c2b>] do_syscall_64+0x80/0x191
 [<ffffffff816825e4>] entry_SYSCALL64_slow_path+0x25/0x25
Code: 56 41 55 41 54 53 48 81 ec a8 00 00 00 44 8b 71 04 8b 42 04 4c 8b 67 18 45 85 f6 89 45 80 0f 84 b4 06 00 00 85 c0 75 2f 41 ff ce <49> c7 04 24 01 00 00 00 b0 01 75 0b 48 8b 41 18 48 83 38 01 0f
RIP  [<ffffffff8138ce5d>] mpi_powm+0x32/0x7e6
 RSP <ffff880401297ad8>
CR2: 0000000000000000
---[ end trace d82015255d4a5d8d ]---

Basically, this is a backport of a libgcrypt patch:

	http://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git;a=patch;h=6e1adb05d290aeeb1c230c763970695f4a538526

Fixes: cdec9cb516 ("crypto: GnuPG based MPI lib - source files (part 1)")
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
cc: linux-ima-devel@lists.sourceforge.net
cc: stable@vger.kernel.org
Signed-off-by: James Morris <james.l.morris@oracle.com>
2016-11-25 12:57:50 +11:00
Herbert Xu
4816c94064 lib/mpi: Fix SG miter leak
In mpi_read_raw_from_sgl we may leak the SG miter resouces after
reading the leading zeroes.  This patch fixes this by stopping the
iteration once the leading zeroes have been read.

Fixes: 127827b9c2 ("lib/mpi: Do not do sg_virt")
Reported-by: Nicolai Stange <nicstange@gmail.com>
Tested-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-07-29 18:30:16 +08:00
Herbert Xu
127827b9c2 lib/mpi: Do not do sg_virt
Currently the mpi SG helpers use sg_virt which is completely
broken.  It happens to work with normal kernel memory but will
fail with anything that is not linearly mapped.

This patch fixes this by using the SG iterator helpers.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-07-01 23:45:18 +08:00
Herbert Xu
9b45b7bba3 crypto: rsa - Generate fixed-length output
Every implementation of RSA that we have naturally generates
output with leading zeroes.  The one and only user of RSA,
pkcs1pad wants to have those leading zeroes in place, in fact
because they are currently absent it has to write those zeroes
itself.

So we shouldn't be stripping leading zeroes in the first place.
In fact this patch makes rsa-generic produce output with fixed
length so that pkcs1pad does not need to do any extra work.

This patch also changes DH to use the new interface.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-07-01 23:45:18 +08:00
Nicolai Stange
20b5b7f3c2 lib/mpi: refactor mpi_read_from_buffer() in terms of mpi_read_raw_data()
mpi_read_from_buffer() and mpi_read_raw_data() do basically the same thing
except that the former extracts the number of payload bits from the first
two bytes of the input buffer.

Besides that, the data copying logic is exactly the same.

Replace the open coded buffer to MPI instance conversion by a call to
mpi_read_raw_data().

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-05-31 16:42:01 +08:00
Nicolai Stange
cdf24b42c6 lib/mpi: mpi_read_from_buffer(): sanitize short buffer printk
The first two bytes of the input buffer encode its expected length and
mpi_read_from_buffer() prints a console message if the given buffer is too
short.

However, there are some oddities with how this message is printed:
- It is printed at the default loglevel. This is different from the
  one used in the case that the first two bytes' value is unsupportedly
  large, i.e. KERN_INFO.
- The format specifier '%d' is used for unsigned ints.
- It prints the values of nread and *ret_nread. This is redundant since
  the former is always the latter + 1.

Clean this up as follows:
- Use pr_info() rather than printk() with no loglevel.
- Use the format specifiers '%u' in place if '%d'.
- Do not print the redundant 'nread' but the more helpful 'nbytes' value.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-05-31 16:42:00 +08:00
Nicolai Stange
7af791e0f0 lib/mpi: mpi_read_from_buffer(): return -EINVAL upon too short buffer
Currently, if the input buffer is shorter than the expected length as
indicated by its first two bytes, an MPI instance of this expected length
will be allocated and filled with as much data as is available. The rest
will remain uninitialized.

Instead of leaving this condition undetected, an error code should be
reported to the caller.

Since this situation indicates that the input buffer's first two bytes,
encoding the number of expected bits, are garbled, -EINVAL is appropriate
here.

If the input buffer is shorter than indicated by its first two bytes,
make mpi_read_from_buffer() return -EINVAL.
Get rid of the 'nread' variable: with the new semantics, the total number
of bytes read from the input buffer is known in advance.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-05-31 16:42:00 +08:00
Nicolai Stange
03cdfaad49 lib/mpi: mpi_read_from_buffer(): return error code
mpi_read_from_buffer() reads a MPI from a buffer into a newly allocated
MPI instance. It expects the buffer's leading two bytes to contain the
number of bits, followed by the actual payload.

On failure, it returns NULL and updates the in/out argument ret_nread
somewhat inconsistently:
- If the given buffer is too short to contain the leading two bytes
  encoding the number of bits or their value is unsupported, then
  ret_nread will be cleared.
- If the allocation of the resulting MPI instance fails, ret_nread is left
  as is.

The only user of mpi_read_from_buffer(), digsig_verify_rsa(), simply checks
for a return value of NULL and returns -ENOMEM if that happens.

While this is all of cosmetic nature only, there is another error condition
which currently isn't detectable by the caller of mpi_read_from_buffer():
if the given buffer is too small to hold the number of bits as encoded in
its first two bytes, the return value will be non-NULL and *ret_nread > 0.

In preparation of communicating this condition to the caller, let
mpi_read_from_buffer() return error values by means of the ERR_PTR()
mechanism.

Make the sole caller of mpi_read_from_buffer(), digsig_verify_rsa(),
check the return value for IS_ERR() rather than == NULL. If IS_ERR() is
true, return the associated error value rather than the fixed -ENOMEM.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-05-31 16:41:59 +08:00
Nicolai Stange
eef0df6a59 lib/mpi: mpi_read_raw_data(): fix nbits calculation
The number of bits, nbits, is calculated in mpi_read_raw_data() as follows:

  nbits = nbytes * 8;

Afterwards, the number of leading zero bits of the first byte get
subtracted:

  nbits -= count_leading_zeros(buffer[0]);

However, count_leading_zeros() takes an unsigned long and thus,
the u8 gets promoted to an unsigned long.

Thus, the above doesn't subtract the number of leading zeros in the most
significant nonzero input byte from nbits, but the number of leading
zeros of the most significant nonzero input byte promoted to unsigned long,
i.e. BITS_PER_LONG - 8 too many.

Fix this by subtracting

  count_leading_zeros(...) - (BITS_PER_LONG - 8)

from nbits only.

Fixes: e104599294 ("MPILIB: Provide a function to read raw data into an
                     MPI")
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-05-31 16:41:59 +08:00
Nicolai Stange
dfd9051067 lib/mpi: mpi_read_raw_data(): purge redundant clearing of nbits
In mpi_read_raw_data(), unsigned nbits is calculated as follows:

 nbits = nbytes * 8;

and redundantly cleared later on if nbytes == 0:

  if (nbytes > 0)
    ...
  else
    nbits = 0;

Purge this redundant clearing for the sake of clarity.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-05-31 16:41:58 +08:00
Nicolai Stange
4bdf1cfca5 lib/mpi: purge mpi_set_buffer()
mpi_set_buffer() has no in-tree users and similar functionality is provided
by mpi_read_raw_data().

Remove mpi_set_buffer().

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-05-31 16:41:58 +08:00
Nicolai Stange
0bb5c9ead6 lib/mpi: mpi_read_raw_from_sgl(): fix out-of-bounds buffer access
Within the copying loop in mpi_read_raw_from_sgl(), the last input SGE's
byte count gets artificially extended as follows:

  if (sg_is_last(sg) && (len % BYTES_PER_MPI_LIMB))
    len += BYTES_PER_MPI_LIMB - (len % BYTES_PER_MPI_LIMB);

Within the following byte copying loop, this causes reads beyond that
SGE's allocated buffer:

  BUG: KASAN: slab-out-of-bounds in mpi_read_raw_from_sgl+0x331/0x650
                                     at addr ffff8801e168d4d8
  Read of size 1 by task systemd-udevd/721
  [...]
  Call Trace:
   [<ffffffff818c4d35>] dump_stack+0xbc/0x117
   [<ffffffff818c4c79>] ? _atomic_dec_and_lock+0x169/0x169
   [<ffffffff814af5d1>] ? print_section+0x61/0xb0
   [<ffffffff814b1109>] print_trailer+0x179/0x2c0
   [<ffffffff814bc524>] object_err+0x34/0x40
   [<ffffffff814bfdc7>] kasan_report_error+0x307/0x8c0
   [<ffffffff814bf315>] ? kasan_unpoison_shadow+0x35/0x50
   [<ffffffff814bf38e>] ? kasan_kmalloc+0x5e/0x70
   [<ffffffff814c0ad1>] kasan_report+0x71/0xa0
   [<ffffffff81938171>] ? mpi_read_raw_from_sgl+0x331/0x650
   [<ffffffff814bf1a6>] __asan_load1+0x46/0x50
   [<ffffffff81938171>] mpi_read_raw_from_sgl+0x331/0x650
   [<ffffffff817f41b6>] rsa_verify+0x106/0x260
   [<ffffffff817f40b0>] ? rsa_set_pub_key+0xf0/0xf0
   [<ffffffff818edc79>] ? sg_init_table+0x29/0x50
   [<ffffffff817f4d22>] ? pkcs1pad_sg_set_buf+0xb2/0x2e0
   [<ffffffff817f5b74>] pkcs1pad_verify+0x1f4/0x2b0
   [<ffffffff81831057>] public_key_verify_signature+0x3a7/0x5e0
   [<ffffffff81830cb0>] ? public_key_describe+0x80/0x80
   [<ffffffff817830f0>] ? keyring_search_aux+0x150/0x150
   [<ffffffff818334a4>] ? x509_request_asymmetric_key+0x114/0x370
   [<ffffffff814b83f0>] ? kfree+0x220/0x370
   [<ffffffff818312c2>] public_key_verify_signature_2+0x32/0x50
   [<ffffffff81830b5c>] verify_signature+0x7c/0xb0
   [<ffffffff81835d0c>] pkcs7_validate_trust+0x42c/0x5f0
   [<ffffffff813c391a>] system_verify_data+0xca/0x170
   [<ffffffff813c3850>] ? top_trace_array+0x9b/0x9b
   [<ffffffff81510b29>] ? __vfs_read+0x279/0x3d0
   [<ffffffff8129372f>] mod_verify_sig+0x1ff/0x290
  [...]

The exact purpose of the len extension isn't clear to me, but due to
its form, I suspect that it's a leftover somehow accounting for leading
zero bytes within the most significant output limb.

Note however that without that len adjustement, the total number of bytes
ever processed by the inner loop equals nbytes and thus, the last output
limb gets written at this point. Thus the net effect of the len adjustement
cited above is just to keep the inner loop running for some more
iterations, namely < BYTES_PER_MPI_LIMB ones, reading some extra bytes from
beyond the last SGE's buffer and discarding them afterwards.

Fix this issue by purging the extension of len beyond the last input SGE's
buffer length.

Fixes: 2d4d1eea54 ("lib/mpi: Add mpi sgl helpers")
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-04-05 20:35:51 +08:00
Nicolai Stange
85d541a3d1 lib/mpi: mpi_read_raw_from_sgl(): sanitize meaning of indices
Within the byte reading loop in mpi_read_raw_sgl(), there are two
housekeeping indices used, z and x.

At all times, the index z represents the number of output bytes covered
by the input SGEs for which processing has completed so far. This includes
any leading zero bytes within the most significant limb.

The index x changes its meaning after the first outer loop's iteration
though: while processing the first input SGE, it represents

  "number of leading zero bytes in most significant output limb" +
   "current position within current SGE"

For the remaining SGEs OTOH, x corresponds just to

  "current position within current SGE"

After all, it is only the sum of z and x that has any meaning for the
output buffer and thus, the

  "number of leading zero bytes in most significant output limb"

part can be moved away from x into z from the beginning, opening up the
opportunity for cleaner code.

Before the outer loop iterating over the SGEs, don't initialize z with
zero, but with the number of leading zero bytes in the most significant
output limb. For the inner loop iterating over a single SGE's bytes,
get rid of the buf_shift offset to x' bounds and let x run from zero to
sg->length - 1.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-04-05 20:35:51 +08:00
Nicolai Stange
64c09b0b59 lib/mpi: mpi_read_raw_from_sgl(): fix nbits calculation
The number of bits, nbits, is calculated in mpi_read_raw_from_sgl() as
follows:

  nbits = nbytes * 8;

Afterwards, the number of leading zero bits of the first byte get
subtracted:

  nbits -= count_leading_zeros(*(u8 *)(sg_virt(sgl) + lzeros));

However, count_leading_zeros() takes an unsigned long and thus,
the u8 gets promoted to an unsigned long.

Thus, the above doesn't subtract the number of leading zeros in the most
significant nonzero input byte from nbits, but the number of leading
zeros of the most significant nonzero input byte promoted to unsigned long,
i.e. BITS_PER_LONG - 8 too many.

Fix this by subtracting

  count_leading_zeros(...) - (BITS_PER_LONG - 8)

from nbits only.

Fixes: 2d4d1eea54 ("lib/mpi: Add mpi sgl helpers")
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-04-05 20:35:51 +08:00
Nicolai Stange
60e1b74c22 lib/mpi: mpi_read_raw_from_sgl(): purge redundant clearing of nbits
In mpi_read_raw_from_sgl(), unsigned nbits is calculated as follows:

  nbits = nbytes * 8;

and redundantly cleared later on if nbytes == 0:

  if (nbytes > 0)
    ...
  else
    nbits = 0;

Purge this redundant clearing for the sake of clarity.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-04-05 20:35:51 +08:00
Nicolai Stange
ab1e912ec1 lib/mpi: mpi_read_raw_from_sgl(): don't include leading zero SGEs in nbytes
At the very beginning of mpi_read_raw_from_sgl(), the leading zeros of
the input scatterlist are counted:

  lzeros = 0;
  for_each_sg(sgl, sg, ents, i) {
    ...
    if (/* sg contains nonzero bytes */)
      break;

    /* sg contains nothing but zeros here */
    ents--;
    lzeros = 0;
  }

Later on, the total number of trailing nonzero bytes is calculated by
subtracting the number of leading zero bytes from the total number of input
bytes:

  nbytes -= lzeros;

However, since lzeros gets reset to zero for each completely zero leading
sg in the loop above, it doesn't include those.

Besides wasting resources by allocating a too large output buffer,
this mistake propagates into the calculation of x, the number of
leading zeros within the most significant output limb:

  x = BYTES_PER_MPI_LIMB - nbytes % BYTES_PER_MPI_LIMB;

What's more, the low order bytes of the output, equal in number to the
extra bytes in nbytes, are left uninitialized.

Fix this by adjusting nbytes for each completely zero leading scatterlist
entry.

Fixes: 2d4d1eea54 ("lib/mpi: Add mpi sgl helpers")
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-04-05 20:35:50 +08:00
Nicolai Stange
b698538951 lib/mpi: mpi_read_raw_from_sgl(): replace len argument by nbytes
Currently, the nbytes local variable is calculated from the len argument
as follows:

  ... mpi_read_raw_from_sgl(..., unsigned int len)
  {
    unsigned nbytes;
    ...
    if (!ents)
      nbytes = 0;
    else
      nbytes = len - lzeros;
    ...
  }

Given that nbytes is derived from len in a trivial way and that the len
argument is shadowed by a local len variable in several loops, this is just
confusing.

Rename the len argument to nbytes and get rid of the nbytes local variable.
Do the nbytes calculation in place.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-04-05 20:35:49 +08:00
Nicolai Stange
462696fd0f lib/mpi: mpi_read_buffer(): fix buffer overflow
Currently, mpi_read_buffer() writes full limbs to the output buffer
and moves memory around to purge leading zero limbs afterwards.

However, with

  commit 9cbe21d8f8 ("lib/mpi: only require buffers as big as needed for
                        the integer")

the caller is only required to provide a buffer large enough to hold the
result without the leading zeros.

This might result in a buffer overflow for small MP numbers with leading
zeros.

Fix this by coping the result to its final destination within the output
buffer and not copying the leading zeros at all.

Fixes: 9cbe21d8f8 ("lib/mpi: only require buffers as big as needed for
                      the integer")
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-04-05 20:35:49 +08:00
Nicolai Stange
90f864e200 lib/mpi: mpi_read_buffer(): replace open coded endian conversion
Currently, the endian conversion from CPU order to BE is open coded in
mpi_read_buffer().

Replace this by the centrally provided cpu_to_be*() macros.
Copy from the temporary storage on stack to the destination buffer
by means of memcpy().

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-04-05 20:35:49 +08:00
Nicolai Stange
f00fa2417b lib/mpi: mpi_read_buffer(): optimize skipping of leading zero limbs
Currently, if the number of leading zeros is greater than fits into a
complete limb, mpi_read_buffer() skips them by iterating over them
limb-wise.

Instead of skipping the high order zero limbs within the loop as shown
above, adjust the copying loop's bounds.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-04-05 20:35:49 +08:00
Nicolai Stange
d755290689 lib/mpi: mpi_write_sgl(): replace open coded endian conversion
Currently, the endian conversion from CPU order to BE is open coded in
mpi_write_sgl().

Replace this by the centrally provided cpu_to_be*() macros.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-04-05 20:35:48 +08:00
Nicolai Stange
cece762f6f lib/mpi: mpi_write_sgl(): fix out-of-bounds stack access
Within the copying loop in mpi_write_sgl(), we have

  if (lzeros) {
    mpi_limb_t *limb1 = (void *)p - sizeof(alimb);
    mpi_limb_t *limb2 = (void *)p - sizeof(alimb)
                               + lzeros;
    *limb1 = *limb2;
    ...
  }

where p points past the end of alimb2 which lives on the stack and contains
the current limb in BE order.

The purpose of the above is to shift the non-zero bytes of alimb2 to its
beginning in memory, i.e. to skip its leading zero bytes.

However, limb2 points somewhere into the middle of alimb2 and thus, reading
*limb2 pulls in lzero bytes from somewhere.

Indeed, KASAN splats:

  BUG: KASAN: stack-out-of-bounds in mpi_write_to_sgl+0x4e3/0x6f0
                                      at addr ffff8800cb04f601
  Read of size 8 by task systemd-udevd/391
  page:ffffea00032c13c0 count:0 mapcount:0 mapping:   (null) index:0x0
  flags: 0x3fff8000000000()
  page dumped because: kasan: bad access detected
  CPU: 3 PID: 391 Comm: systemd-udevd Tainted: G  B  L
                                              4.5.0-next-20160316+ #12
  [...]
  Call Trace:
   [<ffffffff8194889e>] dump_stack+0xdc/0x15e
   [<ffffffff819487c2>] ? _atomic_dec_and_lock+0xa2/0xa2
   [<ffffffff814892b5>] ? __dump_page+0x185/0x330
   [<ffffffff8150ffd6>] kasan_report_error+0x5e6/0x8b0
   [<ffffffff814724cd>] ? kzfree+0x2d/0x40
   [<ffffffff819c5bce>] ? mpi_free_limb_space+0xe/0x20
   [<ffffffff819c469e>] ? mpi_powm+0x37e/0x16f0
   [<ffffffff815109f1>] kasan_report+0x71/0xa0
   [<ffffffff819c0353>] ? mpi_write_to_sgl+0x4e3/0x6f0
   [<ffffffff8150ed34>] __asan_load8+0x64/0x70
   [<ffffffff819c0353>] mpi_write_to_sgl+0x4e3/0x6f0
   [<ffffffff819bfe70>] ? mpi_set_buffer+0x620/0x620
   [<ffffffff819c0e6f>] ? mpi_cmp+0xbf/0x180
   [<ffffffff8186e282>] rsa_verify+0x202/0x260

What's more, since lzeros can be anything from 1 to sizeof(mpi_limb_t)-1,
the above will cause unaligned accesses which is bad on non-x86 archs.

Fix the issue, by preparing the starting point p for the upcoming copy
operation instead of shifting the source memory, i.e. alimb2.

Fixes: 2d4d1eea54 ("lib/mpi: Add mpi sgl helpers")
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-04-05 20:35:48 +08:00