From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752357AbdIXLB5 (ORCPT ); Sun, 24 Sep 2017 07:01:57 -0400 Received: from mail-wm0-f65.google.com ([74.125.82.65]:38251 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752002AbdIXK7m (ORCPT ); Sun, 24 Sep 2017 06:59:42 -0400 X-Google-Smtp-Source: AOwi7QB6B/UmSD2bOasmWFE/rClt17RxyUGIj52/2z/RMIeMHihbmo0i2gk5htS85s9SAmQKClrQAA== From: Ingo Molnar To: linux-kernel@vger.kernel.org Cc: Andrew Morton , Eric Biggers , Andy Lutomirski , Borislav Petkov , Dave Hansen , Fenghua Yu , "H . Peter Anvin" , Linus Torvalds , Oleg Nesterov , Peter Zijlstra , Rik van Riel , Thomas Gleixner , Yu-cheng Yu Subject: [PATCH 07/10] x86/fpu: Copy the full header in copy_user_to_xstate() Date: Sun, 24 Sep 2017 12:59:10 +0200 Message-Id: <20170924105913.9157-8-mingo@kernel.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170924105913.9157-1-mingo@kernel.org> References: <20170924105913.9157-1-mingo@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric Biggers This is in preparation to verify the full xstate header as supplied by user-space. Signed-off-by: Eric Biggers Cc: Andy Lutomirski Cc: Dave Hansen Cc: Dmitry Vyukov Cc: Fenghua Yu Cc: Kees Cook Cc: Kevin Hao Cc: Linus Torvalds Cc: Michael Halcrow Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Rik van Riel Cc: Thomas Gleixner Cc: Wanpeng Li Cc: Yu-cheng Yu Cc: kernel-hardening@lists.openwall.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/fpu/xstate.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 325db7850335..0cd7b73c25e8 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -1199,13 +1199,16 @@ int copy_user_to_xstate(struct xregs_state *xsave, const void __user *ubuf) int i; u64 xfeatures; u64 allowed_features; + struct xstate_header hdr; offset = offsetof(struct xregs_state, header); - size = sizeof(xfeatures); + size = sizeof(hdr); - if (__copy_from_user(&xfeatures, ubuf + offset, size)) + if (__copy_from_user(&hdr, ubuf + offset, size)) return -EFAULT; + xfeatures = hdr.xfeatures; + /* * Reject if the user sets any disabled or supervisor features: */ -- 2.11.0