linux-stable.git/include, branch v3.2.101

x86: fix build warnign with 32-bit PAE

2018-03-19T18:58:40+00:00

I ran into a 4.9 build warning in randconfig testing, starting with the
KAISER patches:

arch/x86/kernel/ldt.c: In function 'alloc_ldt_struct':
arch/x86/include/asm/pgtable_types.h:208:24: error: large integer implicitly truncated to unsigned type [-Werror=overflow]
 #define __PAGE_KERNEL  (__PAGE_KERNEL_EXEC | _PAGE_NX)
                        ^
arch/x86/kernel/ldt.c:81:6: note: in expansion of macro '__PAGE_KERNEL'
      __PAGE_KERNEL);
      ^~~~~~~~~~~~~

I originally ran into this last year when the patches were part of linux-next,
and tried to work around it by using the proper 'pteval_t' types consistently,
but that caused additional problems.

This takes a much simpler approach, and makes the argument type of the dummy
helper always 64-bit, which is wide enough for any page table layout and
won't hurt since this call is just an empty stub anyway.

Fixes: 8f0baadf2bea ("kaiser: merged update")
Signed-off-by: Arnd Bergmann 
Acked-by: Kees Cook 
Acked-by: Hugh Dickins 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

nospec: Include dependency

2018-03-19T18:58:39+00:00

commit eb6174f6d1be16b19cfa43dac296bfed003ce1a6 upstream.

The nospec.h header expects the per-architecture header file
 to optionally define array_index_mask_nospec(). Include
that dependency to prevent inadvertent fallback to the default
array_index_mask_nospec() implementation.

The default implementation may not provide a full mitigation
on architectures that perform data value speculation.

Reported-by: Christian Borntraeger 
Signed-off-by: Dan Williams 
Cc: Andy Lutomirski 
Cc: Arjan van de Ven 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: David Woodhouse 
Cc: Greg Kroah-Hartman 
Cc: Josh Poimboeuf 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Will Deacon 
Cc: linux-arch@vger.kernel.org
Link: http://lkml.kernel.org/r/151881605404.17395.1341935530792574707.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Ingo Molnar 
[bwh: Backported to 3.2: include  instead]
Signed-off-by: Ben Hutchings

nospec: Kill array_index_nospec_mask_check()

2018-03-19T18:58:39+00:00

commit 1d91c1d2c80cb70e2e553845e278b87a960c04da upstream.

There are multiple problems with the dynamic sanity checking in
array_index_nospec_mask_check():

* It causes unnecessary overhead in the 32-bit case since integer sized
  @index values will no longer cause the check to be compiled away like
  in the 64-bit case.

* In the 32-bit case it may trigger with user controllable input when
  the expectation is that should only trigger during development of new
  kernel enabling.

* The macro reuses the input parameter in multiple locations which is
  broken if someone passes an expression like 'index++' to
  array_index_nospec().

Reported-by: Linus Torvalds 
Signed-off-by: Dan Williams 
Cc: Andy Lutomirski 
Cc: Arjan van de Ven 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: David Woodhouse 
Cc: Greg Kroah-Hartman 
Cc: Josh Poimboeuf 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Will Deacon 
Cc: linux-arch@vger.kernel.org
Link: http://lkml.kernel.org/r/151881604278.17395.6605847763178076520.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Ingo Molnar 
Signed-off-by: Ben Hutchings

nospec: Move array_index_nospec() parameter checking into separate macro

2018-03-19T18:58:39+00:00

commit 8fa80c503b484ddc1abbd10c7cb2ab81f3824a50 upstream.

For architectures providing their own implementation of
array_index_mask_nospec() in asm/barrier.h, attempting to use WARN_ONCE() to
complain about out-of-range parameters using WARN_ON() results in a mess
of mutually-dependent include files.

Rather than unpick the dependencies, simply have the core code in nospec.h
perform the checking for us.

Signed-off-by: Will Deacon 
Acked-by: Thomas Gleixner 
Cc: Dan Williams 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1517840166-15399-1-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar 
Signed-off-by: Ben Hutchings

x86/retpoline: Avoid retpolines for built-in __init functions

2018-03-19T18:58:38+00:00

commit 66f793099a636862a71c59d4a6ba91387b155e0c upstream.

There's no point in building init code with retpolines, since it runs before
any potentially hostile userspace does. And before the retpoline is actually
ALTERNATIVEd into place, for much of it.

Signed-off-by: David Woodhouse 
Signed-off-by: Thomas Gleixner 
Cc: karahmed@amazon.de
Cc: peterz@infradead.org
Cc: bp@alien8.de
Link: https://lkml.kernel.org/r/1517484441-1420-2-git-send-email-dwmw@amazon.co.uk
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

vfs, fdtable: Prevent bounds-check bypass via speculative execution

2018-03-19T18:58:37+00:00

commit 56c30ba7b348b90484969054d561f711ba196507 upstream.

'fd' is a user controlled value that is used as a data dependency to
read from the 'fdt->fd' array.  In order to avoid potential leaks of
kernel memory values, block speculative execution of the instruction
stream that could issue reads based on an invalid 'file *' returned from
__fcheck_files.

Co-developed-by: Elena Reshetova 
Signed-off-by: Dan Williams 
Signed-off-by: Thomas Gleixner 
Cc: linux-arch@vger.kernel.org
Cc: kernel-hardening@lists.openwall.com
Cc: gregkh@linuxfoundation.org
Cc: Al Viro 
Cc: torvalds@linux-foundation.org
Cc: alan@linux.intel.com
Link: https://lkml.kernel.org/r/151727418500.33451.17392199002892248656.stgit@dwillia2-desk3.amr.corp.intel.com
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

array_index_nospec: Sanitize speculative array de-references

2018-03-19T18:58:36+00:00

commit f3804203306e098dae9ca51540fcd5eb700d7f40 upstream.

array_index_nospec() is proposed as a generic mechanism to mitigate
against Spectre-variant-1 attacks, i.e. an attack that bypasses boundary
checks via speculative execution. The array_index_nospec()
implementation is expected to be safe for current generation CPUs across
multiple architectures (ARM, x86).

Based on an original implementation by Linus Torvalds, tweaked to remove
speculative flows by Alexei Starovoitov, and tweaked again by Linus to
introduce an x86 assembly implementation for the mask generation.

Co-developed-by: Linus Torvalds 
Co-developed-by: Alexei Starovoitov 
Suggested-by: Cyril Novikov 
Signed-off-by: Dan Williams 
Signed-off-by: Thomas Gleixner 
Cc: linux-arch@vger.kernel.org
Cc: kernel-hardening@lists.openwall.com
Cc: Peter Zijlstra 
Cc: Catalin Marinas 
Cc: Will Deacon 
Cc: Russell King 
Cc: gregkh@linuxfoundation.org
Cc: torvalds@linux-foundation.org
Cc: alan@linux.intel.com
Link: https://lkml.kernel.org/r/151727414229.33451.18411580953862676575.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Ben Hutchings

module/retpoline: Warn about missing retpoline in module

2018-03-19T18:58:35+00:00

commit caf7501a1b4ec964190f31f9c3f163de252273b8 upstream.

There's a risk that a kernel which has full retpoline mitigations becomes
vulnerable when a module gets loaded that hasn't been compiled with the
right compiler or the right option.

To enable detection of that mismatch at module load time, add a module info
string "retpoline" at build time when the module was compiled with
retpoline support. This only covers compiled C source, but assembler source
or prebuilt object files are not checked.

If a retpoline enabled kernel detects a non retpoline protected module at
load time, print a warning and report it in the sysfs vulnerability file.

[ tglx: Massaged changelog ]

Signed-off-by: Andi Kleen 
Signed-off-by: Thomas Gleixner 
Cc: David Woodhouse 
Cc: gregkh@linuxfoundation.org
Cc: torvalds@linux-foundation.org
Cc: jeyu@kernel.org
Cc: arjan@linux.intel.com
Link: https://lkml.kernel.org/r/20180125235028.31211-1-andi@firstfloor.org
Signed-off-by: Ben Hutchings

kconfig.h: use __is_defined() to check if MODULE is defined

2018-03-19T18:58:30+00:00

commit 4f920843d248946545415c1bf6120942048708ed upstream.

The macro MODULE is not a config option, it is a per-file build
option.  So, config_enabled(MODULE) is not sensible.  (There is
another case in include/linux/export.h, where config_enabled() is
used against a non-config option.)

This commit renames some macros in include/linux/kconfig.h for the
use for non-config macros and replaces config_enabled(MODULE) with
__is_defined(MODULE).

I am keeping config_enabled() because it is still referenced from
some places, but I expect it would be deprecated in the future.

Signed-off-by: Masahiro Yamada 
Signed-off-by: Michal Marek 
[bwh: Backported to 3.2: drop change in IS_REACHABLE()]
Signed-off-by: Ben Hutchings

sysfs/cpu: Add vulnerability folder

2018-03-19T18:58:29+00:00

commit 87590ce6e373d1a5401f6539f0c59ef92dd924a9 upstream.

As the meltdown/spectre problem affects several CPU architectures, it makes
sense to have common way to express whether a system is affected by a
particular vulnerability or not. If affected the way to express the
mitigation should be common as well.

Create /sys/devices/system/cpu/vulnerabilities folder and files for
meltdown, spectre_v1 and spectre_v2.

Allow architectures to override the show function.

Signed-off-by: Thomas Gleixner 
Reviewed-by: Greg Kroah-Hartman 
Reviewed-by: Konrad Rzeszutek Wilk 
Cc: Peter Zijlstra 
Cc: Will Deacon 
Cc: Dave Hansen 
Cc: Linus Torvalds 
Cc: Borislav Petkov 
Cc: David Woodhouse 
Link: https://lkml.kernel.org/r/20180107214913.096657732@linutronix.de
[bwh: Backported to 3.2: CPU device class is a sysdev_class, not a normal device
 class]
Signed-off-by: Ben Hutchings