kernel-packages team mailing list archive

[Tim Gardner <tim.gardner@xxxxxxxxxxxxx>]

Dann - I think we won't fix this 'cause there really isn't a way to do
it without introducing security issues. Plus, there is a work around as
stated in the bug description, e.g., 'echo 32768 | sudo tee
/proc/sys/vm/mmap_min_addr'

** Also affects: linux (Ubuntu Trusty)
   Importance: Medium
       Status: Confirmed

** Changed in: linux (Ubuntu Trusty)
       Status: Confirmed => Won't Fix

** Changed in: linux (Ubuntu)
       Status: Confirmed => Invalid

-- 
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1302245

Title:
  mmap_min_addr blocks armhf binary support on arm64

Status in “linux” package in Ubuntu:
  Invalid
Status in “linux” source package in Trusty:
  Won't Fix

Bug description:
  As of linux 3.13.0_22.44, unprivileged armhf binaries will not run on a default arm64 Ubuntu install on hardware that supports ARMv7 instructions:
    
  $ LD_LIBRARY_PATH=/home/dannf/armhf/lib:/home/dannf/armhf/lib/arm-linux-gnueabihf /home/dannf/armhf/lib/ld-linux-armhf.so.3 /home/dannf/armhf/bin/true
  /home/dannf/armhf/bin/true: error while loading shared libraries: /home/dannf/armhf/bin/true: failed to map segment from shared object: Operation not permitted

  This appears to be because we set CONFIG_DEFAULT_MMAP_MIN_ADDR to
  65536. If we lower this to 32768, these binaries work:

  $ echo 32768 | sudo tee /proc/sys/vm/mmap_min_addr
  32768
  $ LD_LIBRARY_PATH=/home/dannf/armhf/lib:/home/dannf/armhf/lib/arm-linux-gnueabihf /home/dannf/armhf/lib/ld-linux-armhf.so.3 /home/dannf/armhf/bin/true
  $ echo $?
  0

  Of course, lowering this default has some security implications - and
  it isn't clear how generally useful it is to have armhf compatibility
  support on arm64 systems.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1302245/+subscriptions