From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752377AbdIVRot (ORCPT ); Fri, 22 Sep 2017 13:44:49 -0400 Received: from mail-pg0-f67.google.com ([74.125.83.67]:36310 "EHLO mail-pg0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751882AbdIVRos (ORCPT ); Fri, 22 Sep 2017 13:44:48 -0400 X-Google-Smtp-Source: AOwi7QCnya2G6hPPHRGsBColKAE7/uNuAHJouCvu9EXNFkjwtp2NNsrqV1azA4iDNwakS9E+Q4hmAQ== From: Eric Biggers To: x86@kernel.org Cc: linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com, Andy Lutomirski , Dave Hansen , Dmitry Vyukov , Fenghua Yu , Ingo Molnar , Kevin Hao , Oleg Nesterov , Wanpeng Li , Yu-cheng Yu , Michael Halcrow , Eric Biggers Subject: [PATCH v4 0/3] x86/fpu: prevent leaking FPU registers via invalid FPU state Date: Fri, 22 Sep 2017 10:41:53 -0700 Message-Id: <20170922174156.16780-1-ebiggers3@gmail.com> X-Mailer: git-send-email 2.14.1.821.g8fa685d3b7-goog Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric Biggers This series fixes the bug found by syzkaller where the ptrace syscall can be used to set invalid bits in a task's FPU state. I also found that an equivalent bug was reachable using the sigreturn syscall, so the first patch fixes the bug in both cases. The other two patches start validating the other parts of the xstate_header and make it so that invalid FPU states can no longer be abused to leak the FPU registers of other processes. Changes since v3: - Rebase onto tip/master Changes since v2: - Use an exception handler to handle invalid FPU states (suggested by Andy Lutomirski) - Check the size of xstate_header.reserved at build time (suggested by Dave Hansen) Eric Biggers (3): x86/fpu: don't let userspace set bogus xcomp_bv x86/fpu: tighten validation of user-supplied xstate_header x86/fpu: reinitialize FPU registers if restoring FPU state fails arch/x86/include/asm/fpu/internal.h | 51 +++++++++++------------------------- arch/x86/include/asm/fpu/xstate.h | 25 ++++++++++++++++++ arch/x86/kernel/fpu/regset.c | 17 +++++------- arch/x86/kernel/fpu/signal.c | 18 ++++++++----- arch/x86/kernel/fpu/xstate.c | 52 ++++++++++++++----------------------- arch/x86/mm/extable.c | 24 +++++++++++++++++ 6 files changed, 102 insertions(+), 85 deletions(-) -- 2.14.1.821.g8fa685d3b7-goog