[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.
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Marcus Meissner
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Paul Zirnik
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--- Comment #3 from Paul Zirnik
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--- Comment #4 from Marcus Meissner
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--- Comment #5 from Paul Zirnik
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--- Comment #6 from Marcus Meissner
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--- Comment #7 from Paul Zirnik
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--- Comment #8 from Paul Zirnik
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Marcus Meissner
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Petr Cerny
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Paul Zirnik
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--- Comment #12 from Petr Cerny
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.
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Petr Cerny
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--- Comment #15 from Paul Zirnik
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--- Comment #16 from Petr Cerny
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.
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--- Comment #17 from Paul Zirnik
(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.
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--- Comment #18 from Petr Cerny
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.
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Petr Cerny
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--- Comment #20 from Paul Zirnik
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