group.of.nepali.translators team mailing list archive

[Christian Ehrhardt  <1837444@xxxxxxxxxxxxxxxxxx>]

** Also affects: psmisc (Ubuntu Xenial)
   Importance: Undecided
       Status: New

** Changed in: psmisc (Ubuntu)
       Status: Triaged => Fix Released

** Changed in: psmisc (Ubuntu Xenial)
       Status: New => Triaged

** Changed in: psmisc (Ubuntu Xenial)
   Importance: Undecided => Low

-- 
You received this bug notification because you are a member of नेपाली
भाषा समायोजकहरुको समूह, which is subscribed to Xenial.
Matching subscriptions: Ubuntu 16.04 Bugs
https://bugs.launchpad.net/bugs/1837444

Title:
  pstree seg fault

Status in psmisc package in Ubuntu:
  Fix Released
Status in psmisc source package in Xenial:
  Triaged

Bug description:
  Impact 
  ------

  Users might face a segmentation fault crash while executing 'pstree'. Backporting this fix will avoid 'pstree' breakage in our users' systems under
  certain circumstances.

  This is a timing issue where if the 'get_threadname' function is called and
  during its execution the target thread is deleted, it tries to close a file
  that does not exist anymore. This happens because of a coding issue, 'pstree'
  invokes fclose function even if the fopen function call returns NULL. The
  proposed patch fixes this issue simply moving the fclose function call three
  lines up, inside of a conditional block which guarantees that the file was
  properly open (the pointer to the file is not NULL).

  This bug was introduced in upstream version 22.21 and fixed in version 23.0,
  which means that Xenial is the only affected Ubuntu release:

  $ rmadison psmisc
   psmisc | 22.15-2ubuntu1   | precise         | source, amd64, armel, armhf, i386, powerpc
   psmisc | 22.15-2ubuntu1.2 | precise-updates | source, amd64, armel, armhf, i386, powerpc
   psmisc | 22.20-1ubuntu2   | trusty          | source, amd64, arm64, armhf, i386, powerpc, ppc64el
   psmisc | 22.21-2.1build1  | xenial          | source, amd64, arm64, armhf, i386, powerpc, ppc64el, s390x
   psmisc | 23.1-1           | bionic          | source, amd64, arm64, armhf, i386, ppc64el, s390x
   psmisc | 23.1-1ubuntu0.1  | bionic-updates  | source, amd64, arm64, armhf, i386, ppc64el, s390x
   psmisc | 23.2-1           | disco           | source, amd64, arm64, armhf, i386, ppc64el, s390x
   psmisc | 23.2-1           | eoan            | source, amd64, arm64, armhf, i386, ppc64el, s390x

  
  Test Case
  ---------

  Since timing is an important factor for this issue, it is not easy to
  reproduce via a test case. This bug might pop up in any 'pstree' call
  regardless of the parameters passed to it. When it happens the user
  will be able to notice the segmentation fault immediately in the
  standard output. Below is the stack trace generated by the user who
  reported this bug on Debian [1]:

  Core was generated by `pstree'.
  Program terminated with signal SIGSEGV, Segmentation fault.
  #0  _IO_new_fclose (fp=0x0) at iofclose.c:54
  54	iofclose.c: No such file or directory.
  (gdb) bt
  #0  _IO_new_fclose (fp=0x0) at iofclose.c:54
  #1  0x00000000004037be in ?? ()
  #2  0x0000000000401a43 in ?? ()
  #3  0x00007f577c553b45 in __libc_start_main (main=0x401670, argc=1,
  argv=0x7ffeb6139328, init=<optimized out>, fini=<optimized out>,
  rtld_fini=<optimized out>, stack_end=0x7ffeb6139318) at libc-start.c:287
  #4  0x0000000000401e8d in ?? ()

  
  However, as presented in the last section it is an easily identifiable error
  in the code, and the fix is quite straightforward.

  [1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=815902

  
  Regression Potential 
  --------------------

  There is a potential problem since the bug was not reproducible in our
  side. Timing issues are hard to reproduce in general, so there might
  be another case(s) where this kind of situation can happen. The fix
  impacts only the 'pstree' utility, so any problem with other binaries
  provided by psmisc is not related to this update.


  [Original message]

  As per https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=815902

  Perhaps Xenial needs to be upgraded to use 22.22??

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/psmisc/+bug/1837444/+subscriptions