September 2014 - luv-main

Computer issues with Linux
by Brian May 19 Nov '14

19 Nov '14

Hello, Am having two strange problems that are starting to eerk me with this (relatively new) computer, running Debian wheezy: 1. If I boot anything later then 3.12 kernel, I don't get any display. As in the monitors display black. No cursors of any sort. Changing to a virtual console doesn't help. Booting in rescue mode doesn't help (I think this rules out X-Windows being a problem). If I go back to the 3.12 kernel, everything works perfectly. I also tried plugging monitors into alternative ports just in case it is going to the wrong place, but get nothing - in any case, under 3.12 the computer seems pretty good at automatically working out what ports are active under X-Windows. 01:00.0 VGA compatible controller: NVIDIA Corporation G96 [GeForce 9500 GT] (rev a1) Am currently using the non-free nvidia drivers. Had exactly the same symptoms when I installed the latest kernel without the non-free nvidia kernel modules. I think the problem is occurring before X starts. Computer seems to be up and running, and responsive to crl+alt+del despite not having a display. 2. There seems to be some weird performance problem. e.g. save a 2 kilobyte file in vim, and the computer can completely freeze (all other windows, including xterms, stop responding to user input) for, say 30 seconds, while it is writing that file. Chromium takes ages to load with several tabs, and pages can fail to start properly while it is doing so. Computer has 16GB RAM and is not using any swap. It has 11GB of buffer/cache space: total used free shared buffers cached Mem: 15G 13G 2.1G 0B 1.1G 7.9G -/+ buffers/cache: 4.6G 11G Swap: 3.8G 0B 3.8G Problems occurred before starting chromium, previously I wondered if it was chromium's fault. This is moving disk + RAID1 + LVM + ext4. Bonnie++ results seem to be pretty good, better in fact then my work computer, which doesn't suffer from similar problems. Writing a byte at a time...done Writing intelligently...done Rewriting...done Reading a byte at a time...done Reading intelligently...done start 'em...done...done...done...done...done... Create files in sequential order...done. Stat files in sequential order...done. Delete files in sequential order...done. Create files in random order...done. Stat files in random order...done. Delete files in random order...done. Version 1.96 ------Sequential Output------ --Sequential Input- --Random- Concurrency 1 -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks-- Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP falidae 31904M 1228 94 107313 4 47471 2 +++++ +++ 137886 3 441.8 2 Latency 19141us 12435ms 251ms 19913us 88073us 283ms Version 1.96 ------Sequential Create------ --------Random Create-------- falidae -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete-- files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP 16 +++++ +++ +++++ +++ +++++ +++ +++++ +++ +++++ +++ +++++ +++ Latency 36us 223us 226us 36us 10us 24us 1.96,1.96,falidae,1,1404290654,31904M,,1228,94,107313,4,47471,2,+++++,+++,137886,3,441.8,2,16,,,,,+++++,+++,+++++,+++,+++++,+++,+++++,+++,+++++,+++,+++++,+++,19141us,12435ms,251ms,19913us,88073us,283ms,36us,223us,226us,36us,10us,24us I am currently working on a new theory that the performance problems only occur when the computer is cold and first turned on. I think I have seen evidence to disprove this, but guess I should run bonnie++ as soon as I turn the computer on, just to be sure. Any other ideas? Thanks -- Brian May <brian(a)microcomaustralia.com.au>

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multi monitor hardware / graphics card advice
by h 10 Oct '14

10 Oct '14

Hi, I am sure I have seen a post on (a) newsgroup about this lately, but am unable to find it. Please excuse me posting what I think I should be able to google - but cann't. I run a desktop opensuse / KDE system and I want to replace my existing dual monitor system with a quad monitor system. I am looking for information on the linux support for graphics card setups which support 4+ monitors. I am resigned to using either nvidia or radeon with proprietary drivers, so would appreciate any advice regarding hardware from anyone who has done this sort of thing recently. -- With thanks, H

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Re: bash "Shell Shock" vulnerability
by Rohan McLeod 06 Oct '14

06 Oct '14

James Harper wrote: >> NetComm ADSL2+ Router NB6_REV2_16M >> Software Version: 3.65p >> Login name: admin >> Password: admin >> >> And I'm in. It's a shell, but can't tell what. ps shows a 'sh' process running. >> > Actually: > >> ps --help > BusyBox v1.00 (2010.01.12-11:52+0000) multi-call binary > > Usage: ps > > Report process status > > This version of ps accepts no options. > > So... not bash. > > James > thanks , interesting well that's a relief ! regards Rohan McLeod

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bash "Shell Shock" vulnerability
by Douglas Ray 01 Oct '14

01 Oct '14

those of you who haven't been up into the small hours looking at the bash shellshock bug: summarized here: http://www.theregister.co.uk/2014/09/24/bash_shell_vuln/ which gives the following useful test env X="() { :;} ; echo busted" `which bash` -c "echo completed" and claims the bug exists from version 1.13 .. 4.3. It can be exploited with wget, ssh, http... They quote NIST thus: GNU Bash through 4.3 processes trailing strings after function definitions in the values of environment variables, which allows remote attackers to execute arbitrary code via a crafted environment, as demonstrated by vectors involving the ForceCommand feature in OpenSSH sshd, the mod_cgi and mod_cgid modules in the Apache HTTP Server, scripts executed by unspecified DHCP clients, and other situations in which setting the environment occurs across a privilege boundary from Bash execution. Authentication: Not required to exploit Impact Type: Allows unauthorized disclosure of information; Allows unauthorized modification; Allows disruption of service More details, and an http exploit, are in http://seclists.org/oss-sec/2014/q3/650 Anyone on OS-X, it affects their bash, sh, csh, tcsh, zsh, ksh; ie, all the distributed shells. happy days...

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Re: bash 'Shell Shock' vulnerability
by Peter Ross 29 Sep '14

29 Sep '14

Hi Hannah, > hi peter. I've tested various builds of busybox ash myself and haven't > found the vuln applies. could you supply some more details? It is a QNAP NAS TS-239 Pro2. > were you testing with the () {} string in an HTTP header? No, the web server does not respond anymore. >> Peter Ross wrote: >>> I have an older QNAP NAS appliance (used for backup) that is vulnerable >>> as well. [~] # x='() { :;}; echo VULNERABLE' bash -c : -sh: bash: command not found [~] # x='() { :;}; echo VULNERABLE' sh -c : VULNERABLE [~] # sh --version GNU bash, version 3.2.0(17)-release (i686-pc-linux-gnu) Copyright (C) 2005 Free Software Foundation, Inc. [~] # uname -a Linux backup 2.6.30.6 #1 SMP Sat Apr 10 06:48:32 CST 2010 i686 unknown >>> AFAIK Busybox uses ash. [as Wikipedia says] Obviously not his one. It has a lot of symlinks to busybox on /bin but its shell is bash. Maybe I do a re-install of "something". I am not sure at the moment. It only copies directories and files to it on the weekly base with external disks used to back them up permanently (and partially off-site) If I put the disks somewhere else I do not need the box anymore. It was just a handy box already in place before I started here. Regards Peter

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Re: bash "Shell Shock" vulnerability
by Rohan McLeod 28 Sep '14

28 Sep '14

James Harper wrote: >> Just out of curiosity, >> I thought would try out the above test; >> on the CLI interface on my Netcomm NB64W ADSL2+ router; >> (standard issue iPrimus ). Thought there was a reasonable chance it used >> BASH; >> I can TELNET 192.168.1.1 to a login prompt ; >> but the u/n ADMIN password doesn't seem to be the same as that for the >> WEB interface; >> anyone have any suggestions for a default p/w; >> or is iPrimus likely to have just locked the CLI down with no access >> possible ? >> As mentioned nothing urgent; but responses appreciated ! >> regards Rohan McLeod >> > A few routers I've seen use 'admin' as the username in the web console, but 'root' as the username as telnet. What username are you using for telnet? I had been using "admin" in web console (default p/w "admin"); I just tried "root" with p/w 'admin' ,"(enter)" and "NB6Plus4W" drops Telnet; then, NB6PLUS4W , NB6PLUS4W_IPRIMUS and nb6plus drops Telnet thanks anyway James regards Rohan McLeod > > James >

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Re: bash 'Shell Shock' vulnerability
by Peter Ross 27 Sep '14

27 Sep '14

From: "Rohan McLeod" <rhn(a)jeack.com.au> > Any news regarding mobile phones and routers etc ? I have an older QNAP NAS appliance (used for backup) that is vulnerable as well. The web interface died four weeks ago so it seems to be time to retire it anyway;-) AFAIK Busybox uses ash. That should be okay for some appliances. On an Apple, I wonder what breaks if you point sh and bash to ksh (until the fix comes in) Probably not much. Regards Peter

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Re: bash "Shell Shock" vulnerability
by Peter Ross 26 Sep '14

26 Sep '14

From: "Joh Lindley" <joh.lindley(a)dcwest.net.au> >> Is Apple's sh a bash? I thought they are using FreeBSD's userland (FreeBSD's sh is not affected [at least the tests are negative and there >> is no SA]) > It would appear so. > sh-3.2$ env x='() { :;}; echo vulnerable' bash -c "echo this is a test" vulnerable > this is a test You are calling the bash [not /bin/sh] here. It shows that you have a bash installed. Regards Peter

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Re: bash "Shell Shock" vulnerability
by Peter Ross 26 Sep '14

26 Sep '14

On 26/09/14 5:22 AM, Douglas Ray wrote: > >> Anyone on OS-X, it affects their bash, sh, csh, tcsh, zsh, ksh; ie, all >> the distributed shells. > > only bash and sh. > csh, tcsh, zsh, ksh not vulnerable. Is Apple's sh a bash? I thought they are using FreeBSD's userland (FreeBSD's sh is not affected [at least the tests are negative and there is no SA]) Regards Peter

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Updated web link for MLUG
by Sae Ra Germaine 24 Sep '14

24 Sep '14

Hi All, We'd really appreciate any info anyone might have on this; The link to MLUG - http://www.mlug.org.au - no longer appears current. Does anyone know if MLUG still exists or if per chance the domain has changed? Warm Regards, Sae Ra -- Sae Ra Germaine Ordinary Council Member Linux Australia http://linux.org.au

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