Return-path: Received: from mail-ot0-f194.google.com ([74.125.82.194]:45390 "EHLO mail-ot0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932384AbeAKP65 (ORCPT ); Thu, 11 Jan 2018 10:58:57 -0500 Received: by mail-ot0-f194.google.com with SMTP id o1so2462725oti.12 for ; Thu, 11 Jan 2018 07:58:57 -0800 (PST) MIME-Version: 1.0 In-Reply-To: References: <151520099201.32271.4677179499894422956.stgit@dwillia2-desk3.amr.corp.intel.com> <20180109205549.osb25c4r2h2n2wqx@treble> From: Dan Williams Date: Thu, 11 Jan 2018 07:58:55 -0800 Message-ID: (sfid-20180111_165945_694316_F6BDFD1A) Subject: Re: [PATCH 00/18] prevent bounds-check bypass via speculative execution To: Jiri Kosina Cc: Josh Poimboeuf , Linux Kernel Mailing List , Mark Rutland , Peter Zijlstra , Alan Cox , Srinivas Pandruvada , Will Deacon , Solomon Peachy , "H. Peter Anvin" , Christian Lamparter , Elena Reshetova , linux-arch@vger.kernel.org, Andi Kleen , "James E.J. Bottomley" , linux-scsi , Jonathan Corbet , X86 ML , Ingo Molnar , Alexey Kuznetsov , Zhang Rui , "Linux-media@vger.kernel.org" , Arnd Bergmann , Jan Kara , Eduardo Valentin , Al Viro , qla2xxx-upstream@qlogic.com, Thomas Gleixner , Mauro Carvalho Chehab , Arjan van de Ven , Kalle Valo , Alan Cox , "Martin K. Petersen" , Hideaki YOSHIFUJI , Greg KH , linux-wireless@vger.kernel.org, "Eric W. Biederman" , Netdev , Linus Torvalds , "David S. Miller" , Laurent Pinchart , Alexei Starovoitov Content-Type: text/plain; charset="UTF-8" Sender: linux-wireless-owner@vger.kernel.org List-ID: On Thu, Jan 11, 2018 at 1:54 AM, Jiri Kosina wrote: > On Tue, 9 Jan 2018, Josh Poimboeuf wrote: > >> On Tue, Jan 09, 2018 at 11:44:05AM -0800, Dan Williams wrote: >> > On Tue, Jan 9, 2018 at 11:34 AM, Jiri Kosina wrote: >> > > On Fri, 5 Jan 2018, Dan Williams wrote: >> > > >> > > [ ... snip ... ] >> > >> Andi Kleen (1): >> > >> x86, barrier: stop speculation for failed access_ok >> > >> >> > >> Dan Williams (13): >> > >> x86: implement nospec_barrier() >> > >> [media] uvcvideo: prevent bounds-check bypass via speculative execution >> > >> carl9170: prevent bounds-check bypass via speculative execution >> > >> p54: prevent bounds-check bypass via speculative execution >> > >> qla2xxx: prevent bounds-check bypass via speculative execution >> > >> cw1200: prevent bounds-check bypass via speculative execution >> > >> Thermal/int340x: prevent bounds-check bypass via speculative execution >> > >> ipv6: prevent bounds-check bypass via speculative execution >> > >> ipv4: prevent bounds-check bypass via speculative execution >> > >> vfs, fdtable: prevent bounds-check bypass via speculative execution >> > >> net: mpls: prevent bounds-check bypass via speculative execution >> > >> udf: prevent bounds-check bypass via speculative execution >> > >> userns: prevent bounds-check bypass via speculative execution >> > >> >> > >> Mark Rutland (4): >> > >> asm-generic/barrier: add generic nospec helpers >> > >> Documentation: document nospec helpers >> > >> arm64: implement nospec_ptr() >> > >> arm: implement nospec_ptr() >> > > >> > > So considering the recent publication of [1], how come we all of a sudden >> > > don't need the barriers in ___bpf_prog_run(), namely for LD_IMM_DW and >> > > LDX_MEM_##SIZEOP, and something comparable for eBPF JIT? >> > > >> > > Is this going to be handled in eBPF in some other way? >> > > >> > > Without that in place, and considering Jann Horn's paper, it would seem >> > > like PTI doesn't really lock it down fully, right? >> > >> > Here is the latest (v3) bpf fix: >> > >> > https://patchwork.ozlabs.org/patch/856645/ >> > >> > I currently have v2 on my 'nospec' branch and will move that to v3 for >> > the next update, unless it goes upstream before then. > > Daniel, I guess you're planning to send this still for 4.15? It's pending in the bpf.git tree: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/commit/?id=b2157399cc9 >> That patch seems specific to CONFIG_BPF_SYSCALL. Is the bpf() syscall >> the only attack vector? Or are there other ways to run bpf programs >> that we should be worried about? > > Seems like Alexei is probably the only person in the whole universe who > isn't CCed here ... let's fix that. He will be cc'd on v2 of this series which will be available later today.