From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 50CE2C43381 for ; Mon, 18 Mar 2019 15:54:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 16E8B2087E for ; Mon, 18 Mar 2019 15:54:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="bztIGuVl" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727684AbfCRPw7 (ORCPT ); Mon, 18 Mar 2019 11:52:59 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:45610 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727389AbfCRPwz (ORCPT ); Mon, 18 Mar 2019 11:52:55 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-Id:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=FTAGVNI6Hb9dNTT478wc/mzluBHW5BLlnleIPj09SRw=; b=bztIGuVlW8fPRovP4QQLyyfAGv V0/B/IZL+WxUPWkdiufPmKk2mUXJEdARLT2g30j0Zf5vtHRqXp0kKwwpUqV9D8CsX0CB/hICGogrl 5pAZ6wgu94HMWjmtIvsav6nYy6ExMmIY4vuziXvfOk9wj19vlFw2JKwyLGVvh1SXBviiqlmIi42Fc x7lzNtDuJgiLvbbU3qBgNXwTPZQZNQprHOkbte0WXgPB3nRrz9qMQPVFKUi5xsTqX6dO+kZHg4DgK oMPFQ6S0HcsUmvffmMsicpen8wHX4dJq0npR6EJ+dVOQ+Ba/D1pzmXoN7QEjF+/9JZSNvWXrTQAk+ TQpK17Uw==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1h5uZ9-0006mq-6M; Mon, 18 Mar 2019 15:52:43 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id C5E9225E45D7A; Mon, 18 Mar 2019 16:52:38 +0100 (CET) Message-Id: <20190318155141.189741167@infradead.org> User-Agent: quilt/0.65 Date: Mon, 18 Mar 2019 16:38:54 +0100 From: Peter Zijlstra To: torvalds@linux-foundation.org, tglx@linutronix.de, hpa@zytor.com, julien.thierry@arm.com, will.deacon@arm.com, luto@amacapital.net, mingo@kernel.org, catalin.marinas@arm.com, james.morse@arm.com, valentin.schneider@arm.com, brgerst@gmail.com, jpoimboe@redhat.com, luto@kernel.org, bp@alien8.de, dvlasenk@redhat.com Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, dvyukov@google.com, rostedt@goodmis.org Subject: [PATCH 14/25] x86/uaccess,ubsan: Fix UBSAN vs SMAP References: <20190318153840.906404905@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org UBSAN can insert extra code in random locations; including AC=1 sections. Typically this code is not safe and needs wrapping. So far, only __ubsan_handle_type_mismatch* have been observed in AC=1 sections and therefore only those are annotated. Cc: Dmitry Vyukov Signed-off-by: Peter Zijlstra (Intel) --- lib/Makefile | 1 + lib/ubsan.c | 4 ++++ 2 files changed, 5 insertions(+) --- a/lib/Makefile +++ b/lib/Makefile @@ -263,6 +263,7 @@ obj-$(CONFIG_UCS2_STRING) += ucs2_string obj-$(CONFIG_UBSAN) += ubsan.o UBSAN_SANITIZE_ubsan.o := n +CFLAGS_ubsan.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) obj-$(CONFIG_SBITMAP) += sbitmap.o --- a/lib/ubsan.c +++ b/lib/ubsan.c @@ -17,6 +17,7 @@ #include #include #include +#include #include "ubsan.h" @@ -313,6 +314,7 @@ static void handle_object_size_mismatch( static void ubsan_type_mismatch_common(struct type_mismatch_data_common *data, unsigned long ptr) { + unsigned long flags = user_access_save(); if (!ptr) handle_null_ptr_deref(data); @@ -320,6 +322,8 @@ static void ubsan_type_mismatch_common(s handle_misaligned_access(data, ptr); else handle_object_size_mismatch(data, ptr); + + user_access_restore(flags); } void __ubsan_handle_type_mismatch(struct type_mismatch_data *data,