SSH connection hanging on logout

[Damien Miller]

On Wed, 9 May 2001 mouring at etoh.eviladmin.org wrote:

> Try against the latest CVS snapshot.  Consider even applying the patch
> the patch Markus put out for turn blocking I/O back on.  This is kinda a
> seperate issue.  I can show this problem exists independent of his patch.

This was the latest CVS.

> But your right.  This does not solve protocol 1 hang on exit.  It just
> solves protocol 2 which is a hint that it's the wrong solution.
>
> I must point out that this 'work around' is only required for a LIMITED
> number of platforms.  Which I believe is HP/UX and Linux at this point.
> Which leads me to believe their is something unique to those platforms.
> So it may cause failure on platforms that don't require this work around.

I suspect that the problem may be with the Linux kernel itself and how it
handles filedescriptiors shared between processes. OpenBSD and Solaris
don't exhibit the problem, the sshd child's fds to the shell get properly
closed when it exits.

> My fear is by putting this into the CVS tree even the portable version
> only that we will end up with another 2.3.0pX feasco.  Where we suddenly
> learned what the downfall of the patch is months after the patch is
> applied and almost forgotten about.

yeah - I would much prefer an (avoidable) hang on logout to a potential
data loss.

-d

-- 
| Damien Miller <djm at mindrot.org> \ ``E-mail attachments are the poor man's
| http://www.mindrot.org          /   distributed filesystem'' - Dan Geer