From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from out1-smtp.messagingengine.com ([66.111.4.25]:40065 "EHLO out1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752558AbdGXXpJ (ORCPT ); Mon, 24 Jul 2017 19:45:09 -0400 Subject: WTF: patch "[PATCH] x86/xen: allow userspace access during hypercalls" was seriously submitted to be applied to the 4.12-stable tree? To: marmarek@invisiblethingslab.com, jgross@suse.com Cc: From: Date: Mon, 24 Jul 2017 16:45:02 -0700 Message-ID: <1500939902223208@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: The patch below was submitted to be applied to the 4.12-stable tree. I fail to see how this patch meets the stable kernel rules as found at Documentation/process/stable_kernel_rules.rst. I could be totally wrong, and if so, please respond to and let me know why this patch should be applied. Otherwise, it is now dropped from my patch queues, never to be seen again. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >>From c54590cac51db8ab5fd30156bdaba34af915e629 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marek=20Marczykowski-G=C3=B3recki?= Date: Mon, 26 Jun 2017 14:49:46 +0200 Subject: [PATCH] x86/xen: allow userspace access during hypercalls MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Userspace application can do a hypercall through /dev/xen/privcmd, and some for some hypercalls argument is a pointers to user-provided structure. When SMAP is supported and enabled, hypervisor can't access. So, lets allow it. The same applies to HYPERVISOR_dm_op, where additionally privcmd driver carefully verify buffer addresses. Cc: stable@vger.kernel.org Signed-off-by: Marek Marczykowski-Górecki Reviewed-by: Juergen Gross Signed-off-by: Juergen Gross diff --git a/arch/x86/include/asm/xen/hypercall.h b/arch/x86/include/asm/xen/hypercall.h index 7a4db5fefd15..11071fcd630e 100644 --- a/arch/x86/include/asm/xen/hypercall.h +++ b/arch/x86/include/asm/xen/hypercall.h @@ -43,6 +43,7 @@ #include #include +#include #include #include @@ -216,10 +217,12 @@ privcmd_call(unsigned call, __HYPERCALL_DECLS; __HYPERCALL_5ARG(a1, a2, a3, a4, a5); + stac(); asm volatile("call *%[call]" : __HYPERCALL_5PARAM : [call] "a" (&hypercall_page[call]) : __HYPERCALL_CLOBBER5); + clac(); return (long)__res; } @@ -478,7 +481,11 @@ static inline int HYPERVISOR_dm_op( domid_t dom, unsigned int nr_bufs, struct xen_dm_op_buf *bufs) { - return _hypercall3(int, dm_op, dom, nr_bufs, bufs); + int ret; + stac(); + ret = _hypercall3(int, dm_op, dom, nr_bufs, bufs); + clac(); + return ret; } static inline void