stack stressor can segfault because of shared alternative stack in sighandler

[Colin Ian King]

It turns out that a shared mmap'd altstack is a really bad idea as it can be clobbered by child and parent causing segfaults on the return path out of the handler. Make the altstack privately mapped.

[Colin Ian King (colin-king)]

Fix committed:

https://kernel.ubuntu.com/git/cking/stress-ng.git/commit/?id=1df4ce68bb28ceeb4add7bcb18f3e6bdae58eac4

[Launchpad Janitor (janitor)]

This bug was fixed in the package stress-ng - 0.10.07-1

---------------
stress-ng (0.10.07-1) unstable; urgency=medium

  * Makefile: bump version
  * Remove smatchify script, we now use other tools to static
    analyse stress-ng
  * core-helper: add sanity check if ttyname returns NULL to avoid
    null pointer dereferencing
  * stress-fp-error: fix checks for NaN and Inf (LP: #1846216)
  * Don't show utf8 chars on dump consoles (LP: #1846196)
  * stress-clone: make child process larger to make it more
    OOM-able (LP: #1845948)
  * core-out-of-memory: open and close proc interface after each write
  * Add autobuild detection of getsid() for better portability
  * stress-ng.h: only use x86 target clones for x86 arches
  * stress-rdrand: unroll loop x 4 more times for more throughput
  * inline the __keep_stressing function, reduce call overhead
    for more throughput
  * stress-stack: make alternative signal stack privately
    mapped (LP: #1845464)

 -- Colin King <email address hidden> Tue, 1 Oct 2019 16:39:52 +0100