From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx158.postini.com [74.125.245.158]) by kanga.kvack.org (Postfix) with SMTP id 3E3D96B006E for ; Tue, 2 Oct 2012 20:44:04 -0400 (EDT) Received: by ied10 with SMTP id 10so20187566ied.14 for ; Tue, 02 Oct 2012 17:44:03 -0700 (PDT) Date: Tue, 2 Oct 2012 17:43:20 -0700 (PDT) From: Hugh Dickins Subject: Re: [PATCH] hardening: add PROT_FINAL prot flag to mmap/mprotect In-Reply-To: <20121002153841.a03ad73b.akpm@linux-foundation.org> Message-ID: References: <20120820180037.GV4232@outflux.net> <20121002153841.a03ad73b.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Kees Cook , Ard Biesheuvel , linux-kernel@vger.kernel.org, Al Viro , Ingo Molnar , Srikar Dronamraju , KOSAKI Motohiro , James Morris , Konstantin Khlebnikov , linux-mm@kvack.org On Tue, 2 Oct 2012, Andrew Morton wrote: > On Tue, 2 Oct 2012 15:10:56 -0700 > Kees Cook wrote: > > > >> Has there been any more progress on this patch over-all? > > > > > > No progress. > > > > Al, Andrew, anyone? Thoughts on this? > > (First email is https://lkml.org/lkml/2012/8/14/448) > > Wasn't cc'ed, missed it. > > The patch looks straightforward enough. Have the maintainers of the > runtime linker (I guess that's glibc) provided any feedback on the > proposal? It looks reasonable to me too. I checked through VM_MAYflag handling and don't expect surprises (a few places already turn off VM_MAYWRITE in much the same way that this does, I hadn't realized). I'm disappointed to find that our mmap() is lax about checking its PROT and MAP args, so old kernels will accept PROT_FINAL but do nothing with it. Luckily mprotect() is stricter, so that can be used to check for whether it's supported. The patch does need to be slightly extended though: alpha, mips, parisc and xtensa have their own include/asm/mman.h, which does not include asm-generic/mman-common.h at all. Hugh -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org