From mboxrd@z Thu Jan 1 00:00:00 1970 Reply-To: kernel-hardening@lists.openwall.com Date: Fri, 1 Jul 2011 13:25:34 +0200 From: Ingo Molnar Message-ID: <20110701112534.GG20990@elte.hu> References: <20110622152514.GA9521@albatros> <20110629151436.9be479fb.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110629151436.9be479fb.akpm@linux-foundation.org> Subject: [kernel-hardening] Re: [RFC] ipc: introduce shm_rmid_forced sysctl To: Andrew Morton Cc: Vasiliy Kulikov , kernel-hardening@lists.openwall.com, Randy Dunlap , "Eric W. Biederman" , "Serge E. Hallyn" , Daniel Lezcano , Oleg Nesterov , Tejun Heo , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org List-ID: * Andrew Morton wrote: > > --- a/ipc/shm.c > > +++ b/ipc/shm.c > > @@ -74,6 +74,7 @@ void shm_init_ns(struct ipc_namespace *ns) > > ns->shm_ctlmax = SHMMAX; > > ns->shm_ctlall = SHMALL; > > ns->shm_ctlmni = SHMMNI; > > + ns->shm_rmid_forced = 0; > > ns->shm_tot = 0; > > ipc_init_ids(&shm_ids(ns)); > > } > > The problem is that nobody will test your feature. So for testing > purposes, let's enable the feature by default. I assume this: I'd also strongly argue to keep this as a default. OOM-kills are not part of POSIX and violate POSIX in a number of ways already. Furthermore, if testing shows that this is not actually breaking anything in a serious way we could also in theory simplify the patch and just make this the default behavior with no runtime ability to switch it off. Thanks, Ingo