From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Gunthorpe Subject: Re: [PATCH v4 3/8] tpm: validate event log access before tpm_bios_log_setup Date: Tue, 11 Oct 2016 10:51:43 -0600 Message-ID: <20161011165143.GA6881@obsidianresearch.com> References: <1475051682-23060-1-git-send-email-nayna@linux.vnet.ibm.com> <1475051682-23060-4-git-send-email-nayna@linux.vnet.ibm.com> <20161003171419.GE6801@obsidianresearch.com> <57F9C4C4.2070508@linux.vnet.ibm.com> <20161009232544.GC24139@obsidianresearch.com> <57FAF49D.7040009@linux.vnet.ibm.com> <20161010032113.GA26363@obsidianresearch.com> <57FB1551.9000806@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <57FB1551.9000806-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: tpmdd-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org To: Nayna Cc: tpmdd-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: tpmdd-devel@lists.sourceforge.net On Mon, Oct 10, 2016 at 09:43:05AM +0530, Nayna wrote: > > > On 10/10/2016 08:51 AM, Jason Gunthorpe wrote: > >On Mon, Oct 10, 2016 at 07:23:33AM +0530, Nayna wrote: > > > >>And we pass this as private data to i_node in tpm_bios_log_setup. > > > >>So, we are referring chip as i_node->i_private->chip. > > > >That probably works, but you can't use the i_private = NULL scheme I > >outlined with that. > > Why ? we are doing i_private = NULL during teardown to imply that chip > unregister is in progress. and no more securityfs operations should be done. > So, whether chip is NULL or securityfs_data is NULL, either should be ok. > Isn't it ? How does release() work if you have to do: put_device(&((const struct tpm_securityfs_data *)inode->i_private)->chip.dev) i_private could be null Jason ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot