Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756011AbdGCONI (ORCPT ); Mon, 3 Jul 2017 10:13:08 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:37766 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933187AbdGCNqX (ORCPT ); Mon, 3 Jul 2017 09:46:23 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Joerg Roedel , Andy Lutomirski , Borislav Petkov , Brian Gerst , Dave Hansen , Denys Vlasenko , "H. Peter Anvin" , Josh Poimboeuf , Linus Torvalds , Peter Zijlstra , Thomas Gleixner , Ingo Molnar Subject: [PATCH 4.9 153/172] x86/mpx: Correctly report do_mpx_bt_fault() failures to user-space Date: Mon, 3 Jul 2017 15:35:33 +0200 Message-Id: <20170703133421.504242558@linuxfoundation.org> X-Mailer: git-send-email 2.13.2 In-Reply-To: <20170703133414.260777365@linuxfoundation.org> References: <20170703133414.260777365@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1767 Lines: 57 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Joerg Roedel commit 5ed386ec09a5d75bcf073967e55e895c2607a5c3 upstream. When this function fails it just sends a SIGSEGV signal to user-space using force_sig(). This signal is missing essential information about the cause, e.g. the trap_nr or an error code. Fix this by propagating the error to the only caller of mpx_handle_bd_fault(), do_bounds(), which sends the correct SIGSEGV signal to the process. Signed-off-by: Joerg Roedel Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Dave Hansen Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Fixes: fe3d197f84319 ('x86, mpx: On-demand kernel allocation of bounds tables') Link: http://lkml.kernel.org/r/1491488362-27198-1-git-send-email-joro@8bytes.org Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/mm/mpx.c | 10 +--------- 1 file changed, 1 insertion(+), 9 deletions(-) --- a/arch/x86/mm/mpx.c +++ b/arch/x86/mm/mpx.c @@ -525,15 +525,7 @@ int mpx_handle_bd_fault(void) if (!kernel_managing_mpx_tables(current->mm)) return -EINVAL; - if (do_mpx_bt_fault()) { - force_sig(SIGSEGV, current); - /* - * The force_sig() is essentially "handling" this - * exception, so we do not pass up the error - * from do_mpx_bt_fault(). - */ - } - return 0; + return do_mpx_bt_fault(); } /*