[Bug 160] Race condition in clientloop.c?

[Nicolas Williams]

I haven't tested it.

Nico


On Sun, Mar 17, 2002 at 09:57:37PM +1200, Adrian Pronk wrote:
> Not in 3.0.2p1?  What about in the version I originally posted about, 3.1?
> 
> 
> >http://bugzilla.mindrot.org/show_bug.cgi?id=160
> >
> >Nicolas.Williams at ubsw.com changed:
> >
> >           What    |Removed                     |Added
> >
> ----------------------------------------------------------------------------
> 
> >             Status|NEW                         |RESOLVED
> >         Resolution|                            |FIXED
> >
> >
> >
> >------- Additional Comments From Nicolas.Williams at ubsw.com  2002-03-14
> 08:25 -------
> >Aha!
> >
> >Yes, there is a race. It's there in 2.9p2, but apparently not in 3.0.2p1.
> >
> >Essentially the
> >
> >"if (compat20 && session_closed && !channel_still_open())"
> >
> >check at the top of the client loop is not close enough to the
> >call to select() in client_wait_until_can_do_something(). In fact,
> >client_wait_until_can_do_something() calls channel_prepare_select()
> >which calls channel_handler() which may well call chan_is_dead()
> >which may leave no channels open and yet
> >client_wait_until_can_do_something() will still go into the
> >select().
> 
> On Tue, Mar 12, 2002 at 11:27:19AM +1300, Adrian Pronk wrote:
> > I've just built openssh 3.1 for my Redhat 5.1 system (running on a 486
> > DX-66) using the latest zlib and openssl libraries.
> >
> > Connecting to the machine with ssh seems to work fine (although it takes
> a
> > while to initiate a connection).
> >
> > But when I transfer a file to the machine with scp, it seems to work fine
> > and the scp completes, but an ssh sub-process remains behind on the
> client
> > and an sshd sub-process remains behind on the host.  When I strace them,
> > the client is waiting on a socket and the host is waiting on three
> > different fd's (under 5.1, its hard to tell what they are without making
> an
> > effort :) ).
> >
> > I did not compile the system on the target machine (which is my
> firewall).
> > My old development machine was a RH 5.1 box.  I bought a new box recently
> > and put RH 7.2 on it.  I copied the development RH 5.1 file system on to
> it
> > (including /dev).  I then chroot'ed to that directory , mounted a new
> /proc
> > and had my 5.1 development environment back.  I compiled (make install)
> > openSSL, zlib, openSSH on this and copied the likely output files to the
> > target machine.  I wouldn't think this development environment would
> break
> > anything.
> >
> > Does anyone know off the top of their heads what the problem might be?
> If
> > not, I'll get stuck in and have a look at the code and see if I can see
> > anything.
> 
> 
> --
> Adrian
> 
> _______________________________________________
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> http://www.mindrot.org/mailman/listinfo/openssh-unix-dev
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