ab crashed with SIGSEGV in main()

Bug #450501 reported by Sasha Levin on 2009-10-13
This bug affects 1 person
Affects Status Importance Assigned to Milestone
apache2 (Ubuntu)

Bug Description

Binary package hint: apache2-utils

I ran ab with a high number of connections (-n 1000000000) and got the error.

ProblemType: Crash
Architecture: amd64
Date: Tue Oct 13 18:30:18 2009
DistroRelease: Ubuntu 9.10
ExecutablePath: /usr/sbin/ab
NonfreeKernelModules: fglrx
Package: apache2-utils 2.2.12-1ubuntu2
ProcCmdline: ab -c 1000 -n 1000000000 -r
ProcVersionSignature: Ubuntu 2.6.31-13.45-generic
 Segfault happened at: 0x7f899657cf67: mov %rax,0x0(%rbp)
 PC (0x7f899657cf67) ok
 source "%rax" ok
 destination "0x0(%rbp)" (0x00000000) not located in a known VMA region (needed writable region)!
SegvReason: writing NULL VMA
Signal: 11
SourcePackage: apache2
 ?? () from /usr/sbin/ab
 ?? () from /usr/sbin/ab
 main () from /usr/sbin/ab
Title: ab crashed with SIGSEGV in main()
Uname: Linux 2.6.31-13-generic x86_64

Sasha Levin (sasha-comsleep) wrote :
visibility: private → public
Chuck Short (zulcss) wrote :

Can you give the exact command you used to get this crash dump?


Changed in apache2 (Ubuntu):
importance: Undecided → Low
status: New → Incomplete
Sasha Levin (sasha-comsleep) wrote :

The exact command was in the original report.

"ab -c 1000 -n 1000000000 -r"


StacktraceTop:close_connection (c=0x7f8994280560)
test ()
main (argc=7, argv=0x7fff77762d78)

Changed in apache2 (Ubuntu):
importance: Low → Medium
tags: removed: need-amd64-retrace
Chuck Short (zulcss) wrote :

I was able to reproduce this on karmic.


Changed in apache2 (Ubuntu):
status: Incomplete → Confirmed
Chuck Short (zulcss) wrote :

This is the patch that fixes it:


chuck@kenny:~/work/server/bugs/karmic/apache/build$ ab -c 1000 -n 1000000000 -r
This is ApacheBench, Version 2.3 <$Revision: 655654 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking (be patient)
Cannot allocate memory for result statistics

Will fix it for lucid and do an SRU.

Thanks for the bug report.


Changed in apache2 (Ubuntu):
status: Confirmed → Triaged
status: Triaged → In Progress
Chuck Short (zulcss) on 2009-11-27
Changed in apache2 (Ubuntu):
status: In Progress → Fix Committed
Launchpad Janitor (janitor) wrote :

This bug was fixed in the package apache2 - 2.2.14-5ubuntu2

apache2 (2.2.14-5ubuntu2) lucid; urgency=low

  * debian/patches/203_fix-ab-segfault.dpatch: Fix segfaulting ab when using really
    wacky options. (LP: #450501)
 -- Chuck Short <email address hidden> Mon, 08 Mar 2010 14:53:17 -0500

Changed in apache2 (Ubuntu):
status: Fix Committed → Fix Released
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