From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752377AbdIXLB7 (ORCPT ); Sun, 24 Sep 2017 07:01:59 -0400 Received: from mail-wm0-f66.google.com ([74.125.82.66]:38244 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752001AbdIXK7k (ORCPT ); Sun, 24 Sep 2017 06:59:40 -0400 X-Google-Smtp-Source: AOwi7QBUQVtKd5tpfFJF7nQ8RmaYydHOkHObIze1qXTXeMhilebiT1dgQXgyChNBhMLoAEqKpN74Pw== 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 06/10] x86/fpu: Use validate_xstate_header() to validate the xstate_header in copy_kernel_to_xstate() Date: Sun, 24 Sep 2017 12:59:09 +0200 Message-Id: <20170924105913.9157-7-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 copy_kernel_to_xstate(). 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 | 12 ++---------- 1 file changed, 2 insertions(+), 10 deletions(-) diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index c97c4a9db52a..325db7850335 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -1138,15 +1138,12 @@ int copy_xstate_to_user(void __user *ubuf, struct xregs_state *xsave, unsigned i /* * Convert from a ptrace standard-format kernel buffer to kernel XSAVES format - * and copy to the target thread. This is called from xstateregs_set() and - * there we check the CPU has XSAVES and a whole standard-sized buffer - * exists. + * and copy to the target thread. This is called from xstateregs_set(). */ int copy_kernel_to_xstate(struct xregs_state *xsave, const void *kbuf) { unsigned int offset, size; int i; - u64 allowed_features; struct xstate_header hdr; offset = offsetof(struct xregs_state, header); @@ -1154,12 +1151,7 @@ int copy_kernel_to_xstate(struct xregs_state *xsave, const void *kbuf) memcpy(&hdr, kbuf + offset, size); - /* - * Reject if the user sets any disabled or supervisor features: - */ - allowed_features = xfeatures_mask & ~XFEATURE_MASK_SUPERVISOR; - - if (hdr.xfeatures & ~allowed_features) + if (validate_xstate_header(&hdr)) return -EINVAL; for (i = 0; i < XFEATURE_MAX; i++) { -- 2.11.0