From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751997AbdIXK7i (ORCPT ); Sun, 24 Sep 2017 06:59:38 -0400 Received: from mail-wm0-f65.google.com ([74.125.82.65]:34014 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751908AbdIXK7e (ORCPT ); Sun, 24 Sep 2017 06:59:34 -0400 X-Google-Smtp-Source: AOwi7QDBiYSsd4EmP6c+FusojPXhXyj+TxPk0Z8pffzdJ7G/OGatR5xwOcpnUMSt7SJi8PODu5gh1Q== 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 02/10] x86/fpu: Use validate_xstate_header() to validate the xstate_header in xstateregs_set() Date: Sun, 24 Sep 2017 12:59:05 +0200 Message-Id: <20170924105913.9157-3-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 Tighten the checks in xstateregs_set(). 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/regset.c | 19 ++++++------------- 1 file changed, 6 insertions(+), 13 deletions(-) diff --git a/arch/x86/kernel/fpu/regset.c b/arch/x86/kernel/fpu/regset.c index ee8d2f049818..b831d5b9de99 100644 --- a/arch/x86/kernel/fpu/regset.c +++ b/arch/x86/kernel/fpu/regset.c @@ -141,27 +141,20 @@ int xstateregs_set(struct task_struct *target, const struct user_regset *regset, ret = copy_user_to_xstate(xsave, ubuf); } else { ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, xsave, 0, -1); - - /* xcomp_bv must be 0 when using uncompacted format */ - if (!ret && xsave->header.xcomp_bv) - ret = -EINVAL; + if (!ret) + ret = validate_xstate_header(&xsave->header); } /* - * In case of failure, mark all states as init: - */ - if (ret) - fpstate_init(&fpu->state); - - /* * mxcsr reserved bits must be masked to zero for security reasons. */ xsave->i387.mxcsr &= mxcsr_feature_mask; - xsave->header.xfeatures &= xfeatures_mask; + /* - * These bits must be zero. + * In case of failure, mark all states as init: */ - memset(&xsave->header.reserved, 0, 48); + if (ret) + fpstate_init(&fpu->state); return ret; } -- 2.11.0