On Tue, 2010-02-09 at 18:51 +0100, ext Ramos Falcon, Ernesto wrote: > > >-----Original Message----- > >From: Ameya Palande [mailto:ameya.palande@xxxxxxxxx] > >Sent: Tuesday, February 09, 2010 11:27 AM > >To: Ramos Falcon, Ernesto > >Cc: linux-omap@xxxxxxxxxxxxxxx; Contreras Felipe (Nokia-D/Helsinki); Doyu > >Hiroshi (Nokia-D/Helsinki) > >Subject: Re: [PATCH] DSPBRIDGE: Validate Processor Handle from user > > > >Hi Ernesto, > > > >On Tue, 2010-02-09 at 18:07 +0100, ext Ramos Falcon, Ernesto wrote: > >> From 07b9f6d30c9d363ba0c4cefded8068662e1048c4 Mon Sep 17 00:00:00 2001 > >> From: Ernesto Ramos <ernesto@xxxxxx> > >> Date: Wed, 3 Feb 2010 19:43:31 -0600 > >> Subject: [PATCH] DSPBRIDGE: Validate Processor Handle from user. > >> > >> Add check to validate the Processor handle received > >> from user. > >> > >> Signed-off-by: Ernesto Ramos <ernesto@xxxxxx> > >> --- > >> drivers/dsp/bridge/pmgr/wcd.c | 86 ++++++++++++- > >> drivers/dsp/bridge/rmgr/proc.c | 280 ++++++++++++++-------------------- > >------ > >> 2 files changed, 179 insertions(+), 187 deletions(-) > > > >My understanding: In bridge_open() we allocate a new process_context and > >store it in filp->private_data which can't be modified / tampered by > >user space. > > > >If this understanding is correct, then why we need to perform any > >validation on data hold be process_context pointer stored in > >flip->private_data? > > > >If you don't trust hProcessor handle received from user space arguments > >then instead of using that we can just use pCtxt->hProcessor! > > > > Agree. We plan to remove the Proc Attach and remove the parameter hProcessor handle passed to the user but we have not done it yet because it may impact the API. > > >I don't understand why we need validation so NACK from my side. > > > > We have had some cases where we receive an invalid proc handle from user which resulted in kernel panic. Why are we using a processor handle passed from user space? Instead of checking validity of this parameter can't we just use pCtxt->hProcessor? This way we can get rid of all the checks! Cheers, Ameya. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
