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=-5.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLACK,USER_AGENT_GIT 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 80023C433E1 for ; Tue, 26 May 2020 19:22:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5598F20849 for ; Tue, 26 May 2020 19:22:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590520958; bh=SbiT9tShyeJeTrafTHaX26vSwjPfBaUpDXmf1AKE84s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=MClYfkHRLpnLZAUbIepXd2Ko4ede8CrR9FVvQahXPmWu5h73ENZUJ8Fi73VAHueW3 IuR7qjOZsgRgFJztPlGjl4gVbMaKKCkk+kNyatrvrD6Lb5/Lk1TJkwsZvLZv1I10VC Smb1d9HbhEIykRkof7lDkVdep7Ot3NiDXL6gQgNA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390895AbgEZTKD (ORCPT ); Tue, 26 May 2020 15:10:03 -0400 Received: from mail.kernel.org ([198.145.29.99]:39106 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2403989AbgEZTJ6 (ORCPT ); Tue, 26 May 2020 15:09:58 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DC5E720873; Tue, 26 May 2020 19:09:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590520197; bh=SbiT9tShyeJeTrafTHaX26vSwjPfBaUpDXmf1AKE84s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zfaUG+JjtHxf0EpzqiNj4ItmoMeNVDuY4/eaWbRdg5bI60D6M+pZ26rJMabtOQtdn ywb6WypMK0jCQreOJqSJrYUrkVwcZzhLgxhUSfaExxl//qRcwQp3+oPIHjLTvyPDlp wtD6/WFEHGMekYVr0wSZkWTK4ETbcmSCeNeVKMAs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, kernel test robot , Marco Elver , Andrew Morton , Andrey Konovalov , Dmitry Vyukov , Alexander Potapenko , Andrey Ryabinin , Qian Cai , Linus Torvalds Subject: [PATCH 5.4 096/111] kasan: disable branch tracing for core runtime Date: Tue, 26 May 2020 20:53:54 +0200 Message-Id: <20200526183942.024415645@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200526183932.245016380@linuxfoundation.org> References: <20200526183932.245016380@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Marco Elver commit 33cd65e73abd693c00c4156cf23677c453b41b3b upstream. During early boot, while KASAN is not yet initialized, it is possible to enter reporting code-path and end up in kasan_report(). While uninitialized, the branch there prevents generating any reports, however, under certain circumstances when branches are being traced (TRACE_BRANCH_PROFILING), we may recurse deep enough to cause kernel reboots without warning. To prevent similar issues in future, we should disable branch tracing for the core runtime. [elver@google.com: remove duplicate DISABLE_BRANCH_PROFILING, per Qian Cai] Link: https://lore.kernel.org/lkml/20200517011732.GE24705@shao2-debian/ Link: http://lkml.kernel.org/r/20200522075207.157349-1-elver@google.com Reported-by: kernel test robot Signed-off-by: Marco Elver Signed-off-by: Andrew Morton Reviewed-by: Andrey Konovalov Cc: Dmitry Vyukov Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Qian Cai Cc: Link: http://lkml.kernel.org/r//20200517011732.GE24705@shao2-debian/ Link: http://lkml.kernel.org/r/20200519182459.87166-1-elver@google.com Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/kasan/Makefile | 8 ++++---- mm/kasan/generic.c | 1 - mm/kasan/tags.c | 1 - 3 files changed, 4 insertions(+), 6 deletions(-) --- a/mm/kasan/Makefile +++ b/mm/kasan/Makefile @@ -14,10 +14,10 @@ CFLAGS_REMOVE_tags.o = $(CC_FLAGS_FTRACE # Function splitter causes unnecessary splits in __asan_load1/__asan_store1 # see: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63533 -CFLAGS_common.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -CFLAGS_generic.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -CFLAGS_generic_report.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -CFLAGS_tags.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) +CFLAGS_common.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING +CFLAGS_generic.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING +CFLAGS_generic_report.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING +CFLAGS_tags.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING obj-$(CONFIG_KASAN) := common.o init.o report.o obj-$(CONFIG_KASAN_GENERIC) += generic.o generic_report.o quarantine.o --- a/mm/kasan/generic.c +++ b/mm/kasan/generic.c @@ -15,7 +15,6 @@ */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt -#define DISABLE_BRANCH_PROFILING #include #include --- a/mm/kasan/tags.c +++ b/mm/kasan/tags.c @@ -12,7 +12,6 @@ */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt -#define DISABLE_BRANCH_PROFILING #include #include