Re: [ANNOUNCEMENT] TEST RELEASE: Cygwin 2.0.0-5

[Corinna Vinschen <corinna-cygwin at cygwin dot com>]

On Apr 16 18:21, Corinna Vinschen wrote:
> On Apr 16 08:17, Jim Reisert AD1C wrote:
> > I am unable to start Cywin/X X-server 1.17.1 with this version.
> > Previous releases of 2.0.0.x were OK.  I had to revert to 1.7.35-1 for
> > the time being.
> > 
> > Other than updating to 2.0.0.5, I also installed the April 2015 "Patch
> > Tuesday" updates from Microsoft.  I don't know if the two are related.
> >   Windows 7 Home Premium, 64-bit
> > 
> > Exception: STATUS_ACCESS_VIOLATION at eip=77C50F8A
> > eax=00000000 ebx=612D67B0 ecx=00001000 edx=612D2648 esi=00000000 edi=0028C790
> > ebp=0028C608 esp=0028C604 program=C:\Cygwin\bin\XWin.exe, pid 1660, thread main
> > cs=0023 ds=002B es=002B fs=0053 gs=002B ss=002B
> > Stack trace:
> > Frame     Function  Args
> > 0028C608  77C50F8A (00000000, 612D2648, 00000000, 612D67B0)
> > 0028C738  610CDA1F (000043FF, 00000000, 00000000, 80012428)

On second thought, if I can trust the args output, that would be an
fchmod(0,0).  If there's no uid or gid 0, which there isn't unless you
explicitely created them in the passwd/group files, the uid and gid have
no SID connected to.  This may be the culprit here.

> I could add an extra check which refuses to change permissions if
> the account's SID can't be found, but since this occurs very deep
> in the call stack, the error message might be pretty vapid.
> 
> Alternatively I just let this slip through and you might wonder
> why the group hasn't changed in this case.

I added a change to this effect, but it occuurs to me that this may
be really just a missing test if the uid and gid values are backed by
a real Windows account.  It seems better to return EPERM here.


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat

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