Re: sshd fork failure

[marco atzeri <marco dot atzeri at gmail dot com>]

On 10/13/2012 6:54 PM, Christopher Faylor wrote:
> On Sat, Oct 13, 2012 at 06:10:23PM +0200, marco atzeri wrote:
> > On 10/13/2012 5:39 PM, Christopher Faylor wrote:
> > > On Thu, Aug 30, 2012 at 06:44:39PM +0200, marco atzeri wrote:
> > > > Hi,
> > > > tracing the sshd process on latest cygwin shapshot ,
> > > > I see that the fork is failing due to exception C0000005
> > > >
> > > >       1       1 [main] sshd (4644)
> > > > **********************************************
> > > >    5921    5922 [main] sshd (4644) Program name:
> > > > E:\cygwin\usr\sbin\sshd.exe (windows pid 4644)
> > > >      30    5952 [main] sshd (4644) OS version:   Windows NT-6.1
> > > >      25    5977 [main] sshd (4644)
> > > > **********************************************
> > > >     636    6613 [main] sshd (4644) sigprocmask: 0 = sigprocmask (0,
> > > > 0x6123D428, 0x610FBB30)
> > > >     122    6735 [main] sshd 4644 child_copy: cygheap - hp 0x20C low
> > > > 0x612708D0, high 0x61277640, res 1
> > > >    1368    8103 [main] sshd 4644 child_copy: done
> > > > --- Process 4644, exception C0000005 at 61137277
> > > >
> > > >
> > > >
> > > > $ addr2line.exe 61137277 -e /usr/bin/cygwin1.dll
> > > > /netrel/src/cygwin-snapshot-20120827-1/newlib/libc/stdlib/mbtowc_r.c:323
> > > >
> > > > that should be:
> > > >
> > > >    ch = (state->__count == 1) ? t[i++] : state->__value.__wchb[1];
> > > >
> > > > inside __utf8_mbtowc .
> > > > It looks a strange place for a fork failure, but it is used in
> > > > winsup/cygwin/cygheap.cc so it could make sense.
> > > >
> > > > Any suggestion how to follow/debug the child portion of fork ?
> > >
> > > Is this still failing?  We're looking to release 1.7.17 soon.
> >
> > on  20121012 similar but in another location.
> >
> > --- Process 6280, exception C0000005 at 61137DC8
> >    427  147466 [main] sshd 6280 exception::handle: In
> > cygwin_except_handler exception 0xC0000005 at 0x61137DC8 sp 0x289270
> >     67  147533 [main] sshd 6280 exception::handle: In
> > cygwin_except_handler signal 11 at 0x61137DC8
> >     38  147571 [main] sshd 6280 exception::handle: In
> > cygwin_except_handler calling 0x0
> >     37  147608 [main] sshd 6280 exception::handle: Exception:
> > STATUS_ACCESS_VIOLATION
> >
> >   addr2line.exe 61137DC8 -e /usr/bin/cygwin1.dll
> > /netrel/src/cygwin-snapshot-20121012-1/newlib/libc/stdio/findfp.c:296
>
> You seem to be the only person reporting this problem.  Everyone else
> updates to a snapshot to cure ssh problems.  FWIW, that instruction
> shouldn't even be executed.
>
> cgf

I have such issue only on sshd forking and for long time,
so it is not relative to last snapshots.

As this the is only program that involve several USER accounts
I suspect some crippling "corporate" group policy or a very
strange BLODA effect.

Marco



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