Re: sshd: fatal: seteuid XXX : No such device or address

[Houder <houder@xs4all.nl>]

On Fri, 15 Mar 2019 21:41:22, Corinna Vinschen  wrote:

> On Mar 15 20:39, Houder wrote:

> > On Fri, 15 Mar 2019 14:42:47, Corinna Vinschen  wrote:
[snip]

> > > Well, there *is* a solution by using strace.  And hey, we now know what
> > > ENXIO returned from seteuid means, don't we?  It's not all bad :)
> >
> > You do! I do not :-) (as I do not have the machinery at my disposal that
> > is required to provoke this error).
> 
> If I'm not mistaken the error occurs for local machine accounts, not for
> domain accounts.  But either way, this problem can only be straced on
> machines which can reproduce the problem and that's usually the machine
> of the OP in the first place.

OP's machine (or equivalent)? Basically, that is what I stated above (i.e.
attempting to state) ...

Error occurs for local machine accounts? Yes, but not at my place! (I did
not see the error (ENXIO) when the sshd problem came up when cygwin 3 was
introduced -- because I "loop back" when using ssh).

> I'm not sure what you're asking for, what do you want to change in
> Cygwin?

To answer the 2nd part of your question: nothing! (even if I was capable
of changing Cygwin).

I can appreciate(?) the complexity of mapping "Linux" to Windows. Simple
enough (?) in case of something like reading/writing a file, because that
concept (general enough to be) is present in both Windows and "Linux".

Totally different in case of seteuid() and companions ...

(Could the error reporting be improved if the Linux system call would be
 a parameter when mapping Windows failure codes to "Linux" error codes?
 I believe that would be very, very troublesome)

To answer the 1st part of your question ...

.. well, I had hoped that you had seen what Windows function had caused
the "No such device or address" error message to appear ...
(and was willing to share that info :-).

I know that you were the one that introduced ERROR_FILE_INVALID and made
it map to ENXIO (in 2001 ... good gracious, almost 20 years ago).

Presumably, because of the empty file problem in av::setup(), a function
in winsup/cygwin/spawn.cc.

Error code ENXIO occurs at a very different level (lower) in Linux than
the level where seteuid() and companions live ...

That is why I was wondering? what made seteuid() in Cygwin generate this
error ...

So, basically, my interest comes down to curiosity! (and I assumed that
you had seen the error appear when the sshd problem came up).

End of thread? :-)

Henri

=====


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