sshd segfault on login

Bug #371659 reported by Sputnik82
6
This bug affects 1 person
Affects Status Importance Assigned to Milestone
openssh (Ubuntu)
Confirmed
Undecided
Unassigned

Bug Description

Server /var/log/syslog
May 4 12:07:03 laptop kernel: [ 8344.704115] sshd[9287]: segfault at 708421f8 ip b7b33170 sp b70c8fa4 error 6 in libc-2.9.so[b7ac1000+15c000]

Client Output
sputnik@laptop:~$ ssh -v IP
OpenSSH_5.1p1 Debian-5ubuntu1, OpenSSL 0.9.8g 19 Oct 2007
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: Connecting to IP [IP] port 22.
debug1: Connection established.
debug1: identity file /home/sputnik/.ssh/identity type -1
debug1: identity file /home/sputnik/.ssh/id_rsa type -1
debug1: identity file /home/sputnik/.ssh/id_dsa type -1
debug1: Remote protocol version 2.0, remote software version OpenSSH_5.1p1 Debian-5ubuntu1
debug1: match: OpenSSH_5.1p1 Debian-5ubuntu1 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.1p1 Debian-5ubuntu1
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-cbc hmac-md5 none
debug1: kex: client->server aes128-cbc hmac-md5 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
The authenticity of host 'IP (IP)' can't be established.
RSA key fingerprint is 04:51:ea:6d:b5:ec:d3:0e:eb:ce:cf:a1:d0:17:fa:de.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 'IP' (RSA) to the list of known hosts.
debug1: ssh_rsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey,password
debug1: Next authentication method: publickey
debug1: Offering public key: /home/sputnik/.ssh/id_rsa
debug1: Authentications that can continue: publickey,password
debug1: Trying private key: /home/sputnik/.ssh/identity
debug1: Trying private key: /home/sputnik/.ssh/id_rsa
debug1: Trying private key: /home/sputnik/.ssh/id_dsa
debug1: Next authentication method: password
sputnik@IP's password:
Connection closed by IP
sputnik@laptop:~$

ProblemType: Bug
Architecture: i386
DistroRelease: Ubuntu 9.04
Package: openssh-server 1:5.1p1-5ubuntu1
ProcEnviron:
 SHELL=/bin/bash
 LANG=ca_AD.UTF-8
SourcePackage: openssh
Uname: Linux 2.6.28-11-generic i686

Revision history for this message
Sputnik82 (enricherrero) wrote :
Revision history for this message
Jeff Enns (cyberpenguinks) wrote :

Thank you for sending in your report. Could you try something for me, please? On the server-side could you do the following:

sudo /etc/init.d/ssh stop
sudo /usr/sbin/sshd -d 2> ~/strace-sshd.txt

Now try to ssh into the box. Once it fails you can attache the file (strace-sshd.txt in your home directory) here. You can start the ssh daemon again on the server by running:
sudo /etc/init.d/ssh start

Thank you.

Changed in openssh (Ubuntu):
status: New → Incomplete
Revision history for this message
Sputnik82 (enricherrero) wrote : Re: [Bug 371659] Re: sshd segfault on login
Download full text (3.4 KiB)

I attach the output file.
I also have executed gdb with sshd to get more information, the output is in the other file.

Thank you for your help

Enric

----- Mensaje original ----
De: Jeff Enns <email address hidden>
Para: <email address hidden>
Enviado: sábado, 6 de junio, 2009 2:22:44
Asunto: [Bug 371659] Re: sshd segfault on login

Thank you for sending in your report. Could you try something for me,
please? On the server-side could you do the following:

sudo /etc/init.d/ssh stop
sudo /usr/sbin/sshd -d 2> ~/strace-sshd.txt

Now try to ssh into the box. Once it fails you can attache the file (strace-sshd.txt in your home directory) here. You can start the ssh daemon again on the server by running:
sudo /etc/init.d/ssh start

Thank you.

** Changed in: openssh (Ubuntu)
       Status: New => Incomplete

--
sshd segfault on login
https://bugs.launchpad.net/bugs/371659
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Status in “openssh” source package in Ubuntu: Incomplete

Bug description:
Server /var/log/syslog
May 4 12:07:03 laptop kernel: [ 8344.704115] sshd[9287]: segfault at 708421f8 ip b7b33170 sp b70c8fa4 error 6 in libc-2.9.so[b7ac1000+15c000]

Client Output
sputnik@laptop:~$ ssh -v IP
OpenSSH_5.1p1 Debian-5ubuntu1, OpenSSL 0.9.8g 19 Oct 2007
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: Connecting to IP [IP] port 22.
debug1: Connection established.
debug1: identity file /home/sputnik/.ssh/identity type -1
debug1: identity file /home/sputnik/.ssh/id_rsa type -1
debug1: identity file /home/sputnik/.ssh/id_dsa type -1
debug1: Remote protocol version 2.0, remote software version OpenSSH_5.1p1 Debian-5ubuntu1
debug1: match: OpenSSH_5.1p1 Debian-5ubuntu1 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.1p1 Debian-5ubuntu1
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-cbc hmac-md5 none
debug1: kex: client->server aes128-cbc hmac-md5 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
The authenticity of host 'IP (IP)' can't be established.
RSA key fingerprint is 04:51:ea:6d:b5:ec:d3:0e:eb:ce:cf:a1:d0:17:fa:de.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 'IP' (RSA) to the list of known hosts.
debug1: ssh_rsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey,password
debug1: Next authentication method: publickey
debug1: Offering public key: /home/sputnik/.ssh/id_rsa
debug1: Authentications that can continue: publickey,password
debug1: Trying private key: /home/sputnik/.ssh/identity
debug1: Trying private key: /home/sputnik/.ssh/id_rsa
debug1: Trying private key: /home/sputnik/.ssh/id_dsa
debug1: Next authentication method: password
sputnik@IP's password:
Connect...

Read more...

Revision history for this message
Chuck Short (zulcss) wrote :

Thank you for taking the time to report this bug and helping to make Ubuntu better. Please try to obtain a backtrace following the instructions at http://wiki.ubuntu.com/DebuggingProgramCrash and upload the backtrace (as an attachment) to the bug report. This will greatly help us in tracking down your problem.

Revision history for this message
S.Giron (steph-giron) wrote :

Hello,

I am not sure if this is related, but I could reproduce this kind of errors in ubuntu 9.10 because of a wrong /etc/hosts file.

Here is what I get :
2 servers node01 and node02

when connecting to node02 from node01:
stephane@node02:~$ ssh node01
Connection closed by 172.16.230.130

In /var/log/messages on node01 :
Nov 3 23:26:04 node01 kernel: [10483.710403] sshd[4555]: segfault at bed74a40 ip 002a9e1d sp bed74a30 error 6 in libc-2.10.1.so[205000+13e000]

Here is an example of my /etc/hosts, which was the result of a bad vi command :
172.16.230.130 node01
172.16.230.131 node02172.16.230.130 node01
172.16.230.131 node02172.16.230.130 node01
172.16.230.131 node02172.16.230.130 node01
172.16.230.131 node02172.16.230.130 node01
172.16.230.131 node02172.16.230.130 node01
172.16.230.131 node02172.16.230.130 node01
172.16.230.131 node02172.16.230.130 node01
172.16.230.131 node02172.16.230.130 node01
172.16.230.131 node02172.16.230.130 node01
172.16.230.131 node02172.16.230.130 node01
172.16.230.131 node02172.16.230.130 node01
172.16.230.131 node02172.16.230.130 node01
172.16.230.131 node02172.16.230.130 node01
172.16.230.131 node02172.16.230.130 node01
172.16.230.131 node02172.16.230.130 node01
172.16.230.131 node02172.16.230.130 node01
172.16.230.131 node02172.16.230.130 node01
172.16.230.131 node02172.16.230.130 node01
172.16.230.131 node02172.16.230.130 node01
172.16.230.131 node02172.16.230.130 node01
172.16.230.131 node02172.16.230.130 node01
172.16.230.131 node02172.16.230.130 node01
172.16.230.131 node02172.16.230.130 node01
172.16.230.131 node02172.16.230.130 node01
172.16.230.131 node02172.16.230.130 node01
"/etc/hosts" 11107 lines, 499666 characters

Regards,

Stephane

Revision history for this message
Chuck Short (zulcss) wrote :

Thanks for the information.

Regards
chuck

Changed in openssh (Ubuntu):
status: Incomplete → Confirmed
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