linux-stable.git/crypto/rng.c, branch v5.2

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

2019-05-30T18:26:32+00:00

Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman

crypto: user - fix use_after_free of struct xxx_request

2018-12-07T06:15:00+00:00

All crypto_stats functions use the struct xxx_request for feeding stats,
but in some case this structure could already be freed.

For fixing this, the needed parameters (len and alg) will be stored
before the request being executed.
Fixes: cac5818c25d0 ("crypto: user - Implement a generic crypto statistics")
Reported-by: syzbot 

Signed-off-by: Corentin Labbe 
Signed-off-by: Herbert Xu

crypto: user - clean up report structure copying

2018-11-09T09:41:39+00:00

There have been a pretty ridiculous number of issues with initializing
the report structures that are copied to userspace by NETLINK_CRYPTO.
Commit 4473710df1f8 ("crypto: user - Prepare for CRYPTO_MAX_ALG_NAME
expansion") replaced some strncpy()s with strlcpy()s, thereby
introducing information leaks.  Later two other people tried to replace
other strncpy()s with strlcpy() too, which would have introduced even
more information leaks:

    - https://lore.kernel.org/patchwork/patch/954991/
    - https://patchwork.kernel.org/patch/10434351/

Commit cac5818c25d0 ("crypto: user - Implement a generic crypto
statistics") also uses the buggy strlcpy() approach and therefore leaks
uninitialized memory to userspace.  A fix was proposed, but it was
originally incomplete.

Seeing as how apparently no one can get this right with the current
approach, change all the reporting functions to:

- Start by memsetting the report structure to 0.  This guarantees it's
  always initialized, regardless of what happens later.
- Initialize all strings using strscpy().  This is safe after the
  memset, ensures null termination of long strings, avoids unnecessary
  work, and avoids the -Wstringop-truncation warnings from gcc.
- Use sizeof(var) instead of sizeof(type).  This is more robust against
  copy+paste errors.

For simplicity, also reuse the -EMSGSIZE return value from nla_put().

Signed-off-by: Eric Biggers 
Signed-off-by: Herbert Xu

crypto: user - Implement a generic crypto statistics

2018-09-28T04:46:25+00:00

This patch implement a generic way to get statistics about all crypto
usages.

Signed-off-by: Corentin Labbe 
Signed-off-by: Herbert Xu

crypto: rng - ensure that the RNG is ready before using

2017-07-28T09:56:00+00:00

Otherwise, we might be seeding the RNG using bad randomness, which is
dangerous. The one use of this function from within the kernel -- not
from userspace -- is being removed (keys/big_key), so that call site
isn't relevant in assessing this.

Cc: Herbert Xu 
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: Herbert Xu

crypto: rng - Remove unused function __crypto_rng_cast()

2017-06-10T04:04:11+00:00

This fixes the following warning when building with clang:

crypto/rng.c:35:34: error: unused function '__crypto_rng_cast'
    [-Werror,-Wunused-function]

Signed-off-by: Matthias Kaehlcke 
Signed-off-by: Herbert Xu

crypto: Replaced gcc specific attributes with macros from compiler.h

2017-01-12T16:24:39+00:00

Continuing from this commit: 52f5684c8e1e
("kernel: use macros from compiler.h instead of __attribute__((...))")

I submitted 4 total patches. They are part of task I've taken up to
increase compiler portability in the kernel. I've cleaned up the
subsystems under /kernel /mm /block and /security, this patch targets
/crypto.

There is  which provides macros for various gcc specific
constructs. Eg: __weak for __attribute__((weak)). I've cleaned all
instances of gcc specific attributes with the right macros for the crypto
subsystem.

I had to make one additional change into compiler-gcc.h for the case when
one wants to use this: __attribute__((aligned) and not specify an alignment
factor. From the gcc docs, this will result in the largest alignment for
that data type on the target machine so I've named the macro
__aligned_largest. Please advise if another name is more appropriate.

Signed-off-by: Gideon Israel Dsouza 
Signed-off-by: Herbert Xu

crypto: rng - Do not free default RNG when it becomes unused

2015-06-22T07:49:18+00:00

Currently we free the default RNG when its use count hits zero.
This was OK when the IV generators would latch onto the RNG at
instance creation time and keep it until the instance is torn
down.

Now that IV generators only keep the RNG reference during init
time this scheme causes the default RNG to come and go at a high
frequencey.  This is highly undesirable as we want to keep a single
RNG in use unless the admin wants it to be removed.

This patch changes the scheme so that the system RNG once allocated
is never removed unless a specifically requested.

Signed-off-by: Herbert Xu

crypto: rng - Zero seed in crypto_rng_reset

2015-04-22T01:30:21+00:00

If we allocate a seed on behalf ot the user in crypto_rng_reset,
we must ensure that it is zeroed afterwards or the RNG may be
compromised.

Reported-by: Stephan Mueller 
Signed-off-by: Herbert Xu

crypto: rng - Remove old low-level rng interface

2015-04-22T01:30:20+00:00

Now that all rng implementations have switched over to the new
interface, we can remove the old low-level interface.

Signed-off-by: Herbert Xu