[cip-dev] [PATCH 4.4-cip 0/6] Extend user-space ASLR range

[jan.kiszka@siemens.com (Jan Kiszka)]

On 2016-12-09 00:56, Ben Hutchings wrote:
> This is a backport of changes in 4.5 to extend the range of Address
> Space Layout Randomisation for user-space processes.  When enabled, this
> should make some user-space vulnerabilities harder to exploit, but it
> can also cause some applications to fail if they currently use a large
> proportion of the virtual address space.
> 
> The default ASLR range remains the same, but it can be changed through
> kernel config (CONFIG_ARCH_MMAP_RND_BITS) or at run-time through sysctl
> (vm.mmap_rnd_bits).  (For 32-bit compat tasks, the range is controlled
> through CONFIG_ARCH_MMAP_RND_COMPAT_BITS and vm.mmap_rnd_compat_bits.)
> 
> This includes support for arm, arm64 and x86 (32- and 64-bit).  (arm64
> is not currently supported by CIP, but it was easier to include it in
> the backport than to leave it out.)
> 
> For this and other backports, I'm looking for feedback like:
> - Did I miss a follow-up fix or an earlier dependency?
> - Does this cause a regression (other than as explained above)?
> - Are you likely to use it?
> - Are there related features you want in 4.4?
> 
> Ben.
> 
> Daniel Cashman (6):
>   mm: mmap: add new /proc tunable for mmap_base ASLR
>   arm: mm: support ARCH_MMAP_RND_BITS
>   arm64: mm: support ARCH_MMAP_RND_BITS
>   x86: mm: support ARCH_MMAP_RND_BITS
>   drivers: char: random: add get_random_long()
>   mm: ASLR: use get_random_long()
> 
>  Documentation/sysctl/vm.txt      | 29 +++++++++++++++++
>  arch/Kconfig                     | 68 ++++++++++++++++++++++++++++++++++++++++
>  arch/arm/Kconfig                 |  9 ++++++
>  arch/arm/mm/mmap.c               |  3 +-
>  arch/arm64/Kconfig               | 29 +++++++++++++++++
>  arch/arm64/mm/mmap.c             |  8 +++--
>  arch/mips/mm/mmap.c              |  4 +--
>  arch/powerpc/kernel/process.c    |  4 +--
>  arch/powerpc/mm/mmap.c           |  4 +--
>  arch/sparc/kernel/sys_sparc_64.c |  2 +-
>  arch/x86/Kconfig                 | 16 ++++++++++
>  arch/x86/mm/mmap.c               | 12 +++----
>  drivers/char/random.c            | 22 +++++++++++++
>  fs/binfmt_elf.c                  |  2 +-
>  include/linux/mm.h               | 11 +++++++
>  include/linux/random.h           |  1 +
>  kernel/sysctl.c                  | 22 +++++++++++++
>  mm/mmap.c                        | 12 +++++++
>  18 files changed, 240 insertions(+), 18 deletions(-)
> 

Did you try to discuss the back-port topic with the KSPP folks or other
key persons involved in these patches? In the ideal case, the authors
can be CC'ed, do not get annoyed by "these crazy people doing legacy
stuff", and may even do some reviews.

Jan

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