[Bug 688105] New: openssh: PTY allocation request failed on channel
https://bugzilla.novell.com/show_bug.cgi?id=688105 https://bugzilla.novell.com/show_bug.cgi?id=688105#c0 Summary: openssh: PTY allocation request failed on channel 0 Classification: openSUSE Product: openSUSE 11.4 Version: RC 2 Platform: x86-64 OS/Version: openSUSE 11.4 Status: NEW Severity: Major Priority: P5 - None Component: Basesystem AssignedTo: bnc-team-screening@forge.provo.novell.com ReportedBy: paul.zirnik@novell.com QAContact: qa@suse.de Found By: Novell Technical Services Services Priority: 1000 Blocker: Yes since updating from openSUSE 11.3 to 11.4 i'm unable to login to our serial console switches. ssh reports: tami@ashford:~> rpm -q openssh openssh-5.8p1-4.1.x86_64 tami@ashford:~> ssh -i ~/hwlab.key root@r6 -p 3207 PTY allocation request failed on channel 0 for example from a sles10 system everything works fine danneman:~ # rpm -q openssh openssh-4.2p1-18.40.35 danneman:~ # ssh -i ~/hwlab.key root@r6 -p 3207 Avocent CPS1610 S/W Version 1.7 Authentication Complete Connected to Port: 7 115200,8,N,1,NONE - SLES9 works, SLES10 works, SLES11 works, openSUSE 11.1,11.2,11.3 works - only openSUSE 11.4 does not work so something must have been changed between 11.3 and 11.4. There is no change in configuraton files. i can partialy workaround the issue with adding option "-T" to ssh but the session then is far away from usable ... -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
https://bugzilla.novell.com/show_bug.cgi?id=688105 https://bugzilla.novell.com/show_bug.cgi?id=688105#c1 Marcus Meissner <meissner@novell.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |NEEDINFO CC| |meissner@novell.com InfoProvider| |paul.zirnik@novell.com --- Comment #1 from Marcus Meissner <meissner@novell.com> 2011-04-18 11:21:36 UTC --- this is probably the local (11.4) ssh that is not able to allocate a pty. is /dev/pts/ correctly setup and mounted as devpts? use: df /dev/pts -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
https://bugzilla.novell.com/show_bug.cgi?id=688105 https://bugzilla.novell.com/show_bug.cgi?id=688105#c2 Paul Zirnik <paul.zirnik@novell.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEEDINFO |NEW InfoProvider|paul.zirnik@novell.com | --- Comment #2 from Paul Zirnik <paul.zirnik@novell.com> 2011-04-18 11:31:29 UTC --- tami@ashford:~> df /dev/pts Filesystem 1K-blocks Used Available Use% Mounted on devpts i don't think this is a general ssh issue with the setup, as ssh to other systems (like SLES9,10,11 or openSUSE 11.x) works perfectly. -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
https://bugzilla.novell.com/show_bug.cgi?id=688105 https://bugzilla.novell.com/show_bug.cgi?id=688105#c3 --- Comment #3 from Paul Zirnik <paul.zirnik@novell.com> 2011-04-18 11:36:11 UTC --- sorry, output was to short tami@ashford:~> df /dev/pts Filesystem 1K-blocks Used Available Use% Mounted on devpts 0 0 0 - /dev/pts -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
https://bugzilla.novell.com/show_bug.cgi?id=688105 https://bugzilla.novell.com/show_bug.cgi?id=688105#c4 --- Comment #4 from Marcus Meissner <meissner@novell.com> 2011-04-18 11:58:36 UTC --- ssh -v for completeness? strange... -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
https://bugzilla.novell.com/show_bug.cgi?id=688105 https://bugzilla.novell.com/show_bug.cgi?id=688105#c5 --- Comment #5 from Paul Zirnik <paul.zirnik@novell.com> 2011-04-18 12:43:26 UTC --- tami@ashford:~> ssh -v -i ~/hwlab.key root@r6 -p 3207 OpenSSH_5.8p1, OpenSSL 1.0.0c 2 Dec 2010 debug1: Reading configuration data /etc/ssh/ssh_config debug1: Applying options for * debug1: Connecting to r6 [149.44.174.4] port 3207. debug1: Connection established. debug1: identity file /suse/tami/hwlab.key type -1 debug1: identity file /suse/tami/hwlab.key-cert type -1 debug1: Remote protocol version 2.0, remote software version OpenSSH_2.9.9 debug1: match: OpenSSH_2.9.9 pat OpenSSH_2.*,OpenSSH_3.0*,OpenSSH_3.1* debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_5.8 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: sending SSH2_MSG_KEXDH_INIT debug1: expecting SSH2_MSG_KEXDH_REPLY debug1: Server host key: RSA d6:17:c8:9d:17:de:14:49:7e:61:dd:a9:89:6a:16:0c debug1: checking without port identifier debug1: checking without port identifier debug1: Host 'r6' is known and matches the RSA host key. debug1: Found key in /suse/tami/.ssh/known_hosts:545 debug1: found matching key w/out port debug1: ssh_rsa_verify: signature correct debug1: SSH2_MSG_NEWKEYS sent debug1: expecting SSH2_MSG_NEWKEYS debug1: SSH2_MSG_NEWKEYS received debug1: Roaming not allowed by server debug1: SSH2_MSG_SERVICE_REQUEST sent debug1: SSH2_MSG_SERVICE_ACCEPT received debug1: Authentications that can continue: publickey debug1: Next authentication method: publickey debug1: Trying private key: /suse/tami/hwlab.key debug1: read PEM private key done: type RSA debug1: Authentication succeeded (publickey). Authenticated to r6 ([149.44.174.4]:3207). debug1: channel 0: new [client-session] debug1: Entering interactive session. debug1: Sending environment. debug1: Sending env LANG = en_US.UTF-8 PTY allocation request failed on channel 0 tami@ashford:~> -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
https://bugzilla.novell.com/show_bug.cgi?id=688105 https://bugzilla.novell.com/show_bug.cgi?id=688105#c6 --- Comment #6 from Marcus Meissner <meissner@novell.com> 2011-04-18 13:03:12 UTC --- can you also post a working trace? -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
https://bugzilla.novell.com/show_bug.cgi?id=688105 https://bugzilla.novell.com/show_bug.cgi?id=688105#c7 --- Comment #7 from Paul Zirnik <paul.zirnik@novell.com> 2011-04-18 13:23:36 UTC --- tami@ashford:~> ssh -v root@juno OpenSSH_5.8p1, OpenSSL 1.0.0c 2 Dec 2010 debug1: Reading configuration data /etc/ssh/ssh_config debug1: Applying options for * debug1: Connecting to juno [149.44.174.48] port 22. debug1: Connection established. debug1: identity file /suse/tami/.ssh/id_rsa type 1 debug1: identity file /suse/tami/.ssh/id_rsa-cert type -1 debug1: identity file /suse/tami/.ssh/id_dsa type -1 debug1: identity file /suse/tami/.ssh/id_dsa-cert type -1 debug1: identity file /suse/tami/.ssh/id_ecdsa type -1 debug1: identity file /suse/tami/.ssh/id_ecdsa-cert type -1 debug1: Remote protocol version 2.0, remote software version OpenSSH_5.1 debug1: match: OpenSSH_5.1 pat OpenSSH* debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_5.8 debug1: SSH2_MSG_KEXINIT sent debug1: SSH2_MSG_KEXINIT received debug1: kex: server->client aes128-ctr hmac-md5 none debug1: kex: client->server aes128-ctr 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 debug1: Server host key: RSA c9:65:41:8e:fd:44:ed:26:d3:41:d6:7d:07:e9:cc:72 debug1: Host 'juno' is known and matches the RSA host key. debug1: Found key in /suse/tami/.ssh/known_hosts:1133 debug1: ssh_rsa_verify: signature correct debug1: SSH2_MSG_NEWKEYS sent debug1: expecting SSH2_MSG_NEWKEYS debug1: SSH2_MSG_NEWKEYS received debug1: Roaming not allowed by server debug1: SSH2_MSG_SERVICE_REQUEST sent debug1: SSH2_MSG_SERVICE_ACCEPT received debug1: Authentications that can continue: publickey,keyboard-interactive debug1: Next authentication method: publickey debug1: Offering RSA public key: /suse/tami/.ssh/id_rsa debug1: Server accepts key: pkalg ssh-rsa blen 149 debug1: read PEM private key done: type RSA debug1: Authentication succeeded (publickey). Authenticated to juno ([149.44.174.48]:22). debug1: channel 0: new [client-session] debug1: Requesting no-more-sessions@openssh.com debug1: Entering interactive session. debug1: Sending environment. debug1: Sending env LANG = en_US.UTF-8 Last login: Mon Apr 18 09:41:05 2011 from ashford.suse.de juno:~ # juno is SLES11 SP1 -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
https://bugzilla.novell.com/show_bug.cgi?id=688105 https://bugzilla.novell.com/show_bug.cgi?id=688105#c8 --- Comment #8 from Paul Zirnik <paul.zirnik@novell.com> 2011-04-18 13:25:41 UTC --- and the working trace for a connect from SLES10 to the serial console switch danneman:~ # ssh -v -i ~/hwlab.key root@r6 -p 3207 OpenSSH_4.2p1, OpenSSL 0.9.8a 11 Oct 2005 debug1: Reading configuration data /etc/ssh/ssh_config debug1: Applying options for * debug1: Connecting to r6 [149.44.174.4] port 3207. debug1: Connection established. debug1: permanently_set_uid: 0/0 debug1: identity file /root/hwlab.key type -1 debug1: Remote protocol version 2.0, remote software version OpenSSH_2.9.9 debug1: match: OpenSSH_2.9.9 pat OpenSSH_2.*,OpenSSH_3.0*,OpenSSH_3.1* debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_4.2 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: sending SSH2_MSG_KEXDH_INIT debug1: expecting SSH2_MSG_KEXDH_REPLY debug1: Host 'r6' is known and matches the RSA host key. debug1: Found key in /root/.ssh/known_hosts:6 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 debug1: Next authentication method: publickey debug1: Trying private key: /root/hwlab.key debug1: read PEM private key done: type RSA debug1: Authentication succeeded (publickey). debug1: channel 0: new [client-session] debug1: Entering interactive session. debug1: Sending environment. debug1: Sending env LANG = en_US.UTF-8 Avocent CPS1610 S/W Version 1.7 Authentication Complete Connected to Port: 7 115200,8,N,1,NONE -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
https://bugzilla.novell.com/show_bug.cgi?id=688105 https://bugzilla.novell.com/show_bug.cgi?id=688105#c9 Marcus Meissner <meissner@novell.com> changed: What |Removed |Added ---------------------------------------------------------------------------- AssignedTo|bnc-team-screening@forge.pr |pcerny@novell.com |ovo.novell.com | --- Comment #9 from Marcus Meissner <meissner@novell.com> 2011-04-18 13:41:10 UTC --- hmm, nothing trivially visible :/ -> maintainer -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
https://bugzilla.novell.com/show_bug.cgi?id=688105 https://bugzilla.novell.com/show_bug.cgi?id=688105#c10 Petr Cerny <pcerny@novell.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |NEEDINFO InfoProvider| |paul.zirnik@novell.com --- Comment #10 from Petr Cerny <pcerny@novell.com> 2011-04-19 18:15:16 UTC --- Interesting indeed. Paul, what does 'stat /dev/ptmx' say? Could you check /var/log/messages *on the switch*? There could be some info from its sshd. Finally are you able to run a command on the switch from the affected (i.e. non-working) workstation - e.g. listing the aforementioned log: $ssh <your options> "cat /var/log/messages" (or anything else)? -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
https://bugzilla.novell.com/show_bug.cgi?id=688105 https://bugzilla.novell.com/show_bug.cgi?id=688105#c11 Paul Zirnik <paul.zirnik@novell.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEEDINFO |NEW InfoProvider|paul.zirnik@novell.com | --- Comment #11 from Paul Zirnik <paul.zirnik@novell.com> 2011-04-20 09:01:50 UTC --- Hi Petr, unfortunately the serial console switch does not log any messages :( here is the output from "stat /dev/ptmx" from 11.4 system showing the issue tami@ashford:~> stat /dev/ptmx File: `/dev/ptmx' Size: 0 Blocks: 0 IO Block: 4096 character special file Device: 5h/5d Inode: 1962 Links: 1 Device type: 5,2 Access: (0666/crw-rw-rw-) Uid: ( 0/ root) Gid: ( 5/ tty) Access: 2011-04-20 10:21:11.167551696 +0200 Modify: 2011-04-20 10:21:11.159551916 +0200 Change: 2011-04-13 10:53:47.886605529 +0200 Birth: - tami@ashford:~> Sending a command directly to the switch is not possible at all. (I guess this is a limitation of the serial console switch) -> from a working openssh version it will hang-up ... debug1: Sending env LANG = en_US.UTF-8 debug1: Sending command: help .. hang must use ctrl+c .... debug1: channel 0: free: client-session, nchannels 1 Killed by signal 2. -> from 11.4 openssh i get ... debug1: Sending env LANG = en_US.UTF-8 debug1: Sending command: help exec request failed on channel 0 P.S. If you like i can send you the ssh-key and you can try to connect to the serial console switch yourself ? -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
https://bugzilla.novell.com/show_bug.cgi?id=688105 https://bugzilla.novell.com/show_bug.cgi?id=688105#c12 --- Comment #12 from Petr Cerny <pcerny@novell.com> 2011-04-20 09:40:23 UTC --- (In reply to comment #11)
here is the output from "stat /dev/ptmx" from 11.4 system showing the issue
tami@ashford:~> stat /dev/ptmx
I meant on the switch, sorry for confusion.
P.S. If you like i can send you the ssh-key and you can try to connect to the serial console switch yourself ?
That would be great. Is it possible to create an unprivileged account on the switch so that I don't break anything by accident? -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
https://bugzilla.novell.com/show_bug.cgi?id=688105 https://bugzilla.novell.com/show_bug.cgi?id=688105#c14 Petr Cerny <pcerny@novell.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |ASSIGNED --- Comment #14 from Petr Cerny <pcerny@novell.com> 2011-04-21 17:17:25 UTC --- The change has been introduced in openssh-5.6p1, see upstream bug https://bugzilla.mindrot.org/show_bug.cgi?id=1698 Packages at http://download.opensuse.org/repositories/home:/pcerny:/experimental/openSUS... have the change removed, feel free to give these a try while I'll try to come up with something more robust. -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
https://bugzilla.novell.com/show_bug.cgi?id=688105 https://bugzilla.novell.com/show_bug.cgi?id=688105#c15 --- Comment #15 from Paul Zirnik <paul.zirnik@novell.com> 2011-04-26 09:32:14 UTC --- I have tested the packages and for me it solves the issue. I still get the message: PTY allocation request failed on channel 0 but all things i normal use over ssh works - sending CTRL or ALT Key combinations - using escape char - sending BREAK I'm little bit confused with this PTY allocation issue, for me "PTY allocation request failed" means it was not possible to open a terminal on the remote side, but i feel like having a terminal :) -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
https://bugzilla.novell.com/show_bug.cgi?id=688105 https://bugzilla.novell.com/show_bug.cgi?id=688105#c16 --- Comment #16 from Petr Cerny <pcerny@novell.com> 2011-04-26 11:57:05 UTC --- (In reply to comment #15)
I'm little bit confused with this PTY allocation issue, for me "PTY allocation request failed" means it was not possible to open a terminal on the remote side, but i feel like having a terminal :)
I believe this is an incorrect implementation of the ssh server on the switch misleadingly reporting that it failed to open a PTY in a situation where it probably should just silently proceed (didn't look into the protocol though - maybe it's perfectly correct). -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
https://bugzilla.novell.com/show_bug.cgi?id=688105 https://bugzilla.novell.com/show_bug.cgi?id=688105#c17 --- Comment #17 from Paul Zirnik <paul.zirnik@novell.com> 2011-04-26 12:19:42 UTC --- (In reply to comment #16)
(In reply to comment #15)
I'm little bit confused with this PTY allocation issue, for me "PTY allocation request failed" means it was not possible to open a terminal on the remote side, but i feel like having a terminal :)
I believe this is an incorrect implementation of the ssh server on the switch misleadingly reporting that it failed to open a PTY in a situation where it probably should just silently proceed (didn't look into the protocol though - maybe it's perfectly correct).
Yes, but when connecting from older openssh clients there is no error printed at all. IMHO the fix from https://bugzilla.mindrot.org/show_bug.cgi?id=1698 is correct, as it prevents the client from hang when it is not possible to open a PTY. I think the real issue is the newer openssh reports PTY allocation failure, but there is no "real" PTY allocation failure at all. -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
https://bugzilla.novell.com/show_bug.cgi?id=688105 https://bugzilla.novell.com/show_bug.cgi?id=688105#c18 --- Comment #18 from Petr Cerny <pcerny@novell.com> 2011-04-27 11:07:21 UTC --- (In reply to comment #17)
I think the real issue is the newer openssh reports PTY allocation failure, but there is no "real" PTY allocation failure at all.
Yes. In this case, however, there probably isn't any PTY allocation at all - the ssh server in the switch likely just gives the special purpose shell access to the socket, or something like that. -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
https://bugzilla.novell.com/show_bug.cgi?id=688105 https://bugzilla.novell.com/show_bug.cgi?id=688105#c19 Petr Cerny <pcerny@novell.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Priority|P5 - None |P3 - Medium Severity|Major |Normal --- Comment #19 from Petr Cerny <pcerny@novell.com> 2011-05-12 21:16:59 UTC --- decreasing severity, since we have a temporary fix. -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
https://bugzilla.novell.com/show_bug.cgi?id=688105 https://bugzilla.novell.com/show_bug.cgi?id=688105#c20 --- Comment #20 from Paul Zirnik <paul.zirnik@novell.com> 2011-12-08 11:31:59 UTC --- The fix is still not included. Issue happens again after update to 12.1 -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
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