Re: [Qemu-devel] [PATCH] qga: Fix handle fd leak in acquire_privilege()

[Michael Roth <mdroth@linux.vnet.ibm.com>]

Quoting Luiz Capitulino (2014-05-20 14:17:42)
> On Mon, 19 May 2014 15:26:03 +0800
> <arei.gonglei@huawei.com> wrote:
> 
> > From: Gonglei <arei.gonglei@huawei.com>
> > 
> > token should be closed in all conditions.
> > So move CloseHandle(token) to "out" branch.
> 
> Looks good to me. Michael, are you going to pick this one?

Sure I'll queue it. Though i'm a bit surprised OpenProcessToken() will still
return an open handle on failure. Is there any confirmation a handle is
actually getting leaked here, as opposed to just returning a handle that's
already been closed?

If it's the latter case we might end up closing it twice after the change,
so just want to confirm.

> 
> > 
> > Signed-off-by: Wang Rui <moon.wangrui@huawei.com>
> > Signed-off-by: Gonglei <arei.gonglei@huawei.com>
> > ---
> >  qga/commands-win32.c | 6 ++++--
> >  1 file changed, 4 insertions(+), 2 deletions(-)
> > 
> > diff --git a/qga/commands-win32.c b/qga/commands-win32.c
> > index d793dd0..e769396 100644
> > --- a/qga/commands-win32.c
> > +++ b/qga/commands-win32.c
> > @@ -31,7 +31,7 @@
> >  
> >  static void acquire_privilege(const char *name, Error **errp)
> >  {
> > -    HANDLE token;
> > +    HANDLE token = NULL;
> >      TOKEN_PRIVILEGES priv;
> >      Error *local_err = NULL;
> >  
> > @@ -53,13 +53,15 @@ static void acquire_privilege(const char *name, Error **errp)
> >              goto out;
> >          }
> >  
> > -        CloseHandle(token);
> >      } else {
> >          error_set(&local_err, QERR_QGA_COMMAND_FAILED,
> >                    "failed to open privilege token");
> >      }
> >  
> >  out:
> > +    if (token) {
> > +        CloseHandle(token);
> > +    }
> >      if (local_err) {
> >          error_propagate(errp, local_err);
> >      }