Commit Graph

505723 Commits

Author SHA1 Message Date
Leilei Zhao 3f1992c002 crypto: atmel-sha - correct the max burst size
The maximum source and destination burst size is 16
according to the datasheet of Atmel DMA. And the value
is also checked in function at_xdmac_csize of Atmel
DMA driver. With the restrict, the value beyond maximum
value will not be processed in DMA driver, so SHA384 and
SHA512 will not work and the program will wait forever.

So here change the max burst size of all the cases to 16
in order to make SHA384 and SHA512 work and keep consistent
with DMA driver and datasheet.

Signed-off-by: Leilei Zhao <leilei.zhao@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-04-08 22:20:03 +08:00
Leilei Zhao 62728e8202 crypto: atmel-sha - initialize spinlock in probe
Kernel will report "BUG: spinlock lockup suspected on CPU#0"
when CONFIG_DEBUG_SPINLOCK is enabled in kernel config and the
spinlock is used at the first time. It's caused by uninitialized
spinlock, so just initialize it in probe.

Signed-off-by: Leilei Zhao <leilei.zhao@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-04-08 22:20:02 +08:00
Leilei Zhao 803eeae8f3 crypto: atmel-sha - fix sg list management
Having a zero length sg doesn't mean it is the end of the sg list. This
case happens when calculating HMAC of IPSec packet.

Signed-off-by: Leilei Zhao <leilei.zhao@atmel.com>
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-04-08 22:20:02 +08:00
Ludovic Desroches 0099286b66 crypto: atmel-sha - correct the way data are split
When a hash is requested on data bigger than the buffer allocated by the
SHA driver, the way DMA transfers are performed is quite strange:
The buffer is filled at each update request. When full, a DMA transfer
is done. On next update request, another DMA transfer is done. Then we
wait to have a full buffer (or the end of the data) to perform the dma
transfer. Such a situation lead sometimes, on SAMA5D4, to a case where
dma transfer is finished but the data ready irq never comes. Moreover
hash was incorrect in this case.

With this patch, dma transfers are only performed when the buffer is
full or when there is no more data. So it removes the transfer whose size
is equal the update size after the full buffer transmission.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Leilei Zhao <leilei.zhao@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-04-08 22:20:01 +08:00
Leilei Zhao 141824d0ae crypto: atmel-sha - add new version
Add new version of atmel-sha available with SAMA5D4 devices.

Signed-off-by: Leilei Zhao <leilei.zhao@atmel.com>
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-04-08 22:20:01 +08:00
Leilei Zhao cf1f0d1279 crypto: atmel-aes - add new version
Add new version of atmel-aes available with SAMA5D4 devices.

Signed-off-by: Leilei Zhao <leilei.zhao@atmel.com>
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-04-08 22:20:00 +08:00
Tadeusz Struk b4e9705024 crypto: qat - fix double release_firmware on error path
release_firmware was called twice on error path causing an Oops.

Reported-by: Ahsan Atta  <ahsan.atta@intel.com>
Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-04-07 21:34:22 +08:00
Tadeusz Struk 8b5cf097c3 crypto: qat - print ring name in debug output
Ring name was allocated but never refenenced.
It was supposed to be printed out in debug output.

Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-04-07 21:34:21 +08:00
Masanari Iida 1e6232f87b crypto: serpent_sse2 - Fix a typo in Kconfig
This patch fix a spelling typo in crypto/Kconfig.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-04-07 21:34:20 +08:00
Sami Tolvanen f2f770d74a crypto: arm/sha256 - Add optimized SHA-256/224
Add Andy Polyakov's optimized assembly and NEON implementations for
SHA-256/224.

The sha256-armv4.pl script for generating the assembly code is from
OpenSSL commit 51f8d095562f36cdaa6893597b5c609e943b0565.

Compared to sha256-generic these implementations have the following
tcrypt speed improvements on Motorola Nexus 6 (Snapdragon 805):

  bs    b/u      sha256-neon  sha256-asm
  16    16       x1.32        x1.19
  64    16       x1.27        x1.15
  64    64       x1.36        x1.20
  256   16       x1.22        x1.11
  256   64       x1.36        x1.19
  256   256      x1.59        x1.23
  1024  16       x1.21        x1.10
  1024  256      x1.65        x1.23
  1024  1024     x1.76        x1.25
  2048  16       x1.21        x1.10
  2048  256      x1.66        x1.23
  2048  1024     x1.78        x1.25
  2048  2048     x1.79        x1.25
  4096  16       x1.20        x1.09
  4096  256      x1.66        x1.23
  4096  1024     x1.79        x1.26
  4096  4096     x1.82        x1.26
  8192  16       x1.20        x1.09
  8192  256      x1.67        x1.23
  8192  1024     x1.80        x1.26
  8192  4096     x1.85        x1.28
  8192  8192     x1.85        x1.27

Where bs refers to block size and b/u to bytes per update.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Cc: Andy Polyakov <appro@openssl.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-04-03 18:03:40 +08:00
Herbert Xu 87b1675634 crypto: api - Change crypto_unregister_instance argument type
This patch makes crypto_unregister_instance take a crypto_instance
instead of a crypto_alg.  This allows us to remove a duplicate
CRYPTO_ALG_INSTANCE check in crypto_unregister_instance.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-04-03 17:53:32 +08:00
Herbert Xu 1f72371099 crypto: api - Fix races in crypto_unregister_instance
There are multiple problems in crypto_unregister_instance:

1) The cra_refcnt BUG_ON check is racy and can cause crashes.
2) The cra_refcnt check shouldn't exist at all.
3) There is no reference on tmpl to protect the tmpl->free call.

This patch rewrites the function using crypto_remove_spawn which
now morphs into crypto_remove_instance.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-04-03 17:53:32 +08:00
Vutla, Lokesh 13cf394c8c crypto: omap-sham - Add the offset of sg page to vaddr
kmap_atomic() gives only the page address of the input page.
Driver should take care of adding the offset of the scatterlist
within the page to the returned page address.
omap-sham driver is not adding the offset to page and directly operates
on the return vale of kmap_atomic(), because of which the following
error comes when running crypto tests:

00000000: d9 a1 1b 7c aa 90 3b aa 11 ab cb 25 00 b8 ac bf
[    2.338169] 00000010: c1 39 cd ff 48 d0 a8 e2 2b fa 33 a1
[    2.344008] alg: hash: Chunking test 1 failed for omap-sha256

So adding the scatterlist offset to vaddr.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-04-03 17:53:32 +08:00
Allan, Bruce W 64a31be39b crypto: qat - fix checkpatch CODE_INDENT issue
ERROR:CODE_INDENT: code indent should use tabs where possible

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-04-01 22:22:49 +08:00
Allan, Bruce W 724c76ce30 crypto: qat - fix checkpatch COMPARISON_TO_NULL issue
CHECK:COMPARISON_TO_NULL: Comparison to NULL could be written
"!device_reset_wq"

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-04-01 22:22:48 +08:00
Allan, Bruce W af6f2a7bb5 crypto: qat - fix checkpatch BIT_MACRO issues
CHECK:BIT_MACRO: Prefer using the BIT macro

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-04-01 22:22:48 +08:00
Allan, Bruce W f7b3c2d34f crypto: qat - fix checkpatch CONCATENATED_STRING issues
CHECK:CONCATENATED_STRING: Concatenated strings should use spaces between
elements

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-04-01 22:22:47 +08:00
Allan, Bruce W b21582dfd5 crypto: qat - checkpatch PARENTHESIS_ALIGNMENT and LOGICAL_CONTINUATIONS
Cleanup code to fix the subject checkpatch warnings

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-04-01 22:22:46 +08:00
Allan, Bruce W 304989fe59 crypto: qat - fix checkpatch CHECK_SPACING issues
Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-04-01 22:22:46 +08:00
Allan, Bruce W 754a90d3f3 crypto: qat - fix typo
adt_ctl_drv should be adf_ctl_drv

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-04-01 22:22:45 +08:00
Vutla, Lokesh 6d7e7e02a0 crypto: omap-aes - Fix support for unequal lengths
For cases where total length of an input SGs is not same as
length of the input data for encryption, omap-aes driver
crashes. This happens in the case when IPsec is trying to use
omap-aes driver.

To avoid this, we copy all the pages from the input SG list
into a contiguous buffer and prepare a single element SG list
for this buffer with length as the total bytes to crypt, which is
similar thing that is done in case of unaligned lengths.

Fixes: 6242332ff2 ("crypto: omap-aes - Add support for cases of unaligned lengths")
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-04-01 22:22:43 +08:00
Vutla, Lokesh b0a3d8986a crypto: omap-sham - Use pm_runtime_irq_safe()
omap_sham_handle_queue() can be called as part of done_task tasklet.
During this its atomic and any calls to pm functions cannot sleep.

But there is a call to pm_runtime_get_sync() (which can sleep) in
omap_sham_handle_queue(), because of which the following appears:
" [  116.169969] BUG: scheduling while atomic: kworker/0:2/2676/0x00000100"

Add pm_runtime_irq_safe() to avoid this.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-04-01 22:22:43 +08:00
Stephan Mueller 555fa17b2b crypto: sha-mb - mark Multi buffer SHA1 helper cipher
Flag all Multi buffer SHA1 helper ciphers as internal ciphers
to prevent them from being called by normal users.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-03-31 21:21:13 +08:00
Stephan Mueller f52bbf55d1 crypto: mcryptd - process CRYPTO_ALG_INTERNAL
The mcryptd is used as a wrapper around internal ciphers. Therefore,
the mcryptd must process the internal cipher by marking mcryptd as
internal if the underlying cipher is an internal cipher.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-03-31 21:21:13 +08:00
Stephan Mueller cd98411c36 crypto: arm64/aes - mark 64 bit ARMv8 AES helper ciphers
Flag all 64 bit ARMv8 AES helper ciphers as internal ciphers to
prevent them from being called by normal users.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-03-31 21:21:12 +08:00
Stephan Mueller 94a7e5e8d8 crypto: aes-ce - mark ARMv8 AES helper ciphers
Flag all ARMv8 AES helper ciphers as internal ciphers to prevent
them from being called by normal users.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-03-31 21:21:12 +08:00
Stephan Mueller 76aa9d5f2c crypto: aesbs - mark NEON bit sliced AES helper ciphers
Flag all NEON bit sliced AES helper ciphers as internal ciphers to
prevent them from being called by normal users.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-03-31 21:21:11 +08:00
Stephan Mueller 4dda66f62e crypto: twofish_avx - mark Twofish AVX helper ciphers
Flag all Twofish AVX helper ciphers as internal ciphers to prevent
them from being called by normal users.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-03-31 21:21:11 +08:00
Stephan Mueller 748be1f1bf crypto: serpent_sse2 - mark Serpent SSE2 helper ciphers
Flag all Serpent SSE2 helper ciphers as internal ciphers to prevent
them from being called by normal users.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-03-31 21:21:10 +08:00
Stephan Mueller 65aed53941 crypto: serpent_avx - mark Serpent AVX helper ciphers
Flag all Serpent AVX helper ciphers as internal ciphers to prevent
them from being called by normal users.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-03-31 21:21:10 +08:00
Stephan Mueller f82419acd8 crypto: serpent_avx2 - mark Serpent AVX2 helper ciphers
Flag all Serpent AVX2 helper ciphers as internal ciphers to prevent
them from being called by normal users.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-03-31 21:21:09 +08:00
Stephan Mueller e69b8a46ca crypto: cast6_avx - mark CAST6 helper ciphers
Flag all CAST6 helper ciphers as internal ciphers to prevent them
from being called by normal users.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-03-31 21:21:09 +08:00
Stephan Mueller 7d2c31dd70 crypto: camellia_aesni_avx - mark AVX Camellia helper ciphers
Flag all AVX Camellia helper ciphers as internal ciphers to prevent
them from being called by normal users.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-03-31 21:21:08 +08:00
Stephan Mueller 680574e8b3 crypto: cast5_avx - mark CAST5 helper ciphers
Flag all CAST5 helper ciphers as internal ciphers to prevent them
from being called by normal users.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-03-31 21:21:08 +08:00
Stephan Mueller a62356a978 crypto: camellia_aesni_avx2 - mark AES-NI Camellia helper ciphers
Flag all AES-NI Camellia helper ciphers as internal ciphers to
prevent them from being called by normal users.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-03-31 21:21:07 +08:00
Stephan Mueller 4b3f4e37ec crypto: ghash-ce - mark GHASH ARMv8 vmull.p64 helper ciphers
Flag all GHASH ARMv8 vmull.p64 helper ciphers as internal ciphers
to prevent them from being called by normal users.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-03-31 21:21:07 +08:00
Stephan Mueller 6a9b52b7fa crypto: clmulni - mark ghash clmulni helper ciphers
Flag all ash clmulni helper ciphers as internal ciphers to prevent them
from being called by normal users.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-03-31 21:21:06 +08:00
Stephan Mueller eabdc320ec crypto: aesni - mark AES-NI helper ciphers
Flag all AES-NI helper ciphers as internal ciphers to prevent them from
being called by normal users.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-03-31 21:21:05 +08:00
Stephan Mueller b0cda2ba18 crypto: proc - identify internal ciphers
With ciphers that now cannot be accessed via the kernel crypto API,
callers shall be able to identify the ciphers that are not callable. The
/proc/crypto file is added a boolean field identifying that such
internal ciphers.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-03-31 21:21:04 +08:00
Stephan Mueller 466a7b9e3e crypto: cryptd - process CRYPTO_ALG_INTERNAL
The cryptd is used as a wrapper around internal ciphers. Therefore, the
cryptd must process the internal cipher by marking cryptd as internal if
the underlying cipher is an internal cipher.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-03-31 21:21:04 +08:00
Stephan Mueller 425a882991 crypto: testmgr - use CRYPTO_ALG_INTERNAL
Allocate the ciphers irrespectively if they are marked as internal
or not. As all ciphers, including the internal ciphers will be
processed by the testmgr, it needs to be able to allocate those
ciphers.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-03-31 21:21:03 +08:00
Stephan Mueller 06ca7f68d4 crypto: api - prevent helper ciphers from being used
Several hardware related cipher implementations are implemented as
follows: a "helper" cipher implementation is registered with the
kernel crypto API.

Such helper ciphers are never intended to be called by normal users. In
some cases, calling them via the normal crypto API may even cause
failures including kernel crashes. In a normal case, the "wrapping"
ciphers that use the helpers ensure that these helpers are invoked
such that they cannot cause any calamity.

Considering the AF_ALG user space interface, unprivileged users can
call all ciphers registered with the crypto API, including these
helper ciphers that are not intended to be called directly. That
means, with AF_ALG user space may invoke these helper ciphers
and may cause undefined states or side effects.

To avoid any potential side effects with such helpers, the patch
prevents the helpers to be called directly. A new cipher type
flag is added: CRYPTO_ALG_INTERNAL. This flag shall be used
to mark helper ciphers. These ciphers can only be used if the
caller invoke the cipher with CRYPTO_ALG_INTERNAL in the type and
mask field.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-03-31 21:21:03 +08:00
Ard Biesheuvel fa50d7ee45 crypto: arm/ghash - fix big-endian bug in ghash
This fixes a bug in the new v8 Crypto Extensions GHASH code
that only manifests itself in big-endian mode.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-03-24 22:24:56 +11:00
Dan Carpenter a83034f5cb crypto: img-hash - shift wrapping bug in img_hash_hw_init()
"hdev->req->nbytes" is an unsigned int so we so we lose the upper 3 bits
to the shift wrap bug.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-03-23 22:06:50 +11:00
Dan Carpenter 900831a4d9 crypto: img-hash - fix some compile warnings
GCC complains about that %u is the wrong format string for size_t and
also that "ret" is unused.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-03-23 22:06:50 +11:00
Allan, Bruce W 665503049b crypto: qat - make error and info log messages more descriptive
Convert pr_info() and pr_err() log messages to dev_info() and dev_err(),
respectively, where able.  This adds the module name and PCI B:D:F to
indicate which QAT device generated the log message.  The "QAT:" is removed
from these log messages as that is now unnecessary.  A few of these log
messages have additional spelling/contextual fixes.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-03-23 22:06:49 +11:00
Allan, Bruce W 92dd5be559 crypto: qat - fix typo in string
Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-03-23 22:06:48 +11:00
Allan, Bruce W a00204f8e5 crypto: qat - remove duplicate definition of Intel PCI vendor id
This define is a duplicate of the one in ./include/linux/pci_ids.h

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-03-23 22:06:48 +11:00
James Hartley cfa8e7e703 crypto: img-hash - Fix Kconfig selections
The Kconfig entry for CRYPTO_DEV_IMGTEC_HASH incorrectly selects
CRYPTO_SHA224, which does not exist (and is covered by CRYPTO_SHA256
which covers both 224 and 256). Remove it.

Also correct typo CRYPTO_ALG_API to be CRYPTO_ALGPI.

Reported-by: Valentin Rothberg <valentinrothberg@gmail.com>
Signed-off-by: James Hartley <james.hartley@imgtec.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-03-23 22:06:47 +11:00
mancha security 0b053c9518 lib: memzero_explicit: use barrier instead of OPTIMIZER_HIDE_VAR
OPTIMIZER_HIDE_VAR(), as defined when using gcc, is insufficient to
ensure protection from dead store optimization.

For the random driver and crypto drivers, calls are emitted ...

  $ gdb vmlinux
  (gdb) disassemble memzero_explicit
  Dump of assembler code for function memzero_explicit:
    0xffffffff813a18b0 <+0>:	push   %rbp
    0xffffffff813a18b1 <+1>:	mov    %rsi,%rdx
    0xffffffff813a18b4 <+4>:	xor    %esi,%esi
    0xffffffff813a18b6 <+6>:	mov    %rsp,%rbp
    0xffffffff813a18b9 <+9>:	callq  0xffffffff813a7120 <memset>
    0xffffffff813a18be <+14>:	pop    %rbp
    0xffffffff813a18bf <+15>:	retq
  End of assembler dump.

  (gdb) disassemble extract_entropy
  [...]
    0xffffffff814a5009 <+313>:	mov    %r12,%rdi
    0xffffffff814a500c <+316>:	mov    $0xa,%esi
    0xffffffff814a5011 <+321>:	callq  0xffffffff813a18b0 <memzero_explicit>
    0xffffffff814a5016 <+326>:	mov    -0x48(%rbp),%rax
  [...]

... but in case in future we might use facilities such as LTO, then
OPTIMIZER_HIDE_VAR() is not sufficient to protect gcc from a possible
eviction of the memset(). We have to use a compiler barrier instead.

Minimal test example when we assume memzero_explicit() would *not* be
a call, but would have been *inlined* instead:

  static inline void memzero_explicit(void *s, size_t count)
  {
    memset(s, 0, count);
    <foo>
  }

  int main(void)
  {
    char buff[20];

    snprintf(buff, sizeof(buff) - 1, "test");
    printf("%s", buff);

    memzero_explicit(buff, sizeof(buff));
    return 0;
  }

With <foo> := OPTIMIZER_HIDE_VAR():

  (gdb) disassemble main
  Dump of assembler code for function main:
  [...]
   0x0000000000400464 <+36>:	callq  0x400410 <printf@plt>
   0x0000000000400469 <+41>:	xor    %eax,%eax
   0x000000000040046b <+43>:	add    $0x28,%rsp
   0x000000000040046f <+47>:	retq
  End of assembler dump.

With <foo> := barrier():

  (gdb) disassemble main
  Dump of assembler code for function main:
  [...]
   0x0000000000400464 <+36>:	callq  0x400410 <printf@plt>
   0x0000000000400469 <+41>:	movq   $0x0,(%rsp)
   0x0000000000400471 <+49>:	movq   $0x0,0x8(%rsp)
   0x000000000040047a <+58>:	movl   $0x0,0x10(%rsp)
   0x0000000000400482 <+66>:	xor    %eax,%eax
   0x0000000000400484 <+68>:	add    $0x28,%rsp
   0x0000000000400488 <+72>:	retq
  End of assembler dump.

As can be seen, movq, movq, movl are being emitted inlined
via memset().

Reference: http://thread.gmane.org/gmane.linux.kernel.cryptoapi/13764/
Fixes: d4c5efdb97 ("random: add and use memzero_explicit() for clearing data")
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: mancha security <mancha1@zoho.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-03-20 07:56:12 +11:00