From mboxrd@z Thu Jan 1 00:00:00 1970 From: Will Drewry Subject: Re: Compat 32-bit syscall entry from 64-bit task!? Date: Wed, 18 Jan 2012 13:58:26 -0600 Message-ID: References: <20120118015013.GR11715@one.firstfloor.org> <20120118020453.GL7180@jl-vm1.vm.bytemark.co.uk> <20120118022217.GS11715@one.firstfloor.org> <20120118193602.GV11715@one.firstfloor.org> <20120118194420.GW11715@one.firstfloor.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Andi Kleen , Indan Zupancic , Jamie Lokier , Andrew Lutomirski , Oleg Nesterov , linux-kernel@vger.kernel.org, keescook@chromium.org, john.johansen@canonical.com, serge.hallyn@canonical.com, coreyb@linux.vnet.ibm.com, pmoore@redhat.com, eparis@redhat.com, djm@mindrot.org, segoon@openwall.com, rostedt@goodmis.org, jmorris@namei.org, scarybeasts@gmail.com, avi@redhat.com, penberg@cs.helsinki.fi, viro@zeniv.linux.org.uk, mingo@elte.hu, akpm@linux-foundation.org, khilman@ti.com, borislav.petkov@amd.com, amwang@redhat.com, ak@linux.intel.com, eric.dumazet@gmail.com, gregkh@suse.de, dhowells@redhat.com, daniel.lezcano@free.fr, linux-fsdevel@vger.kernel.org, linux-security-module@vger.kernel.org, olofj@chromium.org, mhalcrow@google.com, dlaor@redhat.com, Roland McGrath Return-path: In-Reply-To: Sender: linux-security-module-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Wed, Jan 18, 2012 at 1:52 PM, Will Drewry wrote: > On Wed, Jan 18, 2012 at 1:47 PM, Linus Torvalds > wrote: >> On Wed, Jan 18, 2012 at 11:44 AM, Andi Kleen w= rote: >>> >>> It can securely enable syscall auditing which can catch all syscall= s >>> (however you only get race free memory arguments for the ones with = LSM hooks >>> at the right place). Really need both. >>> >>> I agree it's not easy to get tight (and also not pretty), but you h= ave a lot >>> better chance doing it this way than with ptrace. >> >> .. And how the f*^& did you imagine that something like chrome would= do that? >> >> You need massive amounts of privileges, and it's a total disaster in >> every single respect. >> >> Stop pushing crap. No, ptrace isn't wonderful, but your LSM+auditing >> idea is a billion times worse in all respects. >> >> We can definitely fix the ptrace issue with compat system calls. > > FWIW, it looks like audit needs fixing too. =A0If a process only uses > TIF_SYSCALL_AUDIT, then the fast-path will properly annotate the entr= y > with AUDIT_ARCH_I386, but if it takes the slow path because of some > other tracing on a thread (ftrace, ptrace, ...), then the audit recor= d > will incorrectly use TIF_IA32 to write the audit record. =A0Easy patc= h > (I'll write it up shortly), but yet another case of breakage. Nevermind - mis-derefenced the IS_IA32 define. -- To unsubscribe from this list: send the line "unsubscribe linux-securit= y-module" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html