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=-8.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 ABB83C7618B for ; Mon, 29 Jul 2019 11:20:00 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 0515421655 for ; Mon, 29 Jul 2019 11:19:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=c-s.fr header.i=@c-s.fr header.b="TuKAFDEk" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0515421655 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=c-s.fr Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kernel-hardening-return-16606-kernel-hardening=archiver.kernel.org@lists.openwall.com Received: (qmail 16067 invoked by uid 550); 29 Jul 2019 11:19:54 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Received: (qmail 16032 invoked from network); 29 Jul 2019 11:19:53 -0000 Authentication-Results: localhost; dkim=pass reason="1024-bit key; insecure key" header.d=c-s.fr header.i=@c-s.fr header.b=TuKAFDEk; dkim-adsp=pass; dkim-atps=neutral X-Virus-Scanned: Debian amavisd-new at c-s.fr DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=c-s.fr; s=mail; t=1564399177; bh=QYn92bFk6L4jrJrPT8nEs5INqQRWowzslhlMsgOiPSA=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=TuKAFDEk1hkgNToNlN1eyQg4AAiN/y1nVzlhzB0UZjlCHyoJfk1bRt9tsfHx07rru Ye3bk/tGrBW405QYUU/vw3jlDklTgk6hMg3OYxx4FDU1BAagcqk91VnBNBE4wkesOj FIemEP+b6tkJ5Jx0o4UzuS769fA7CLCTTSDaerQM= X-Virus-Scanned: amavisd-new at c-s.fr Subject: Re: [RFC PATCH 08/10] powerpc/fsl_booke/kaslr: clear the original kernel if randomized To: Jason Yan , mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org, diana.craciun@nxp.com, benh@kernel.crashing.org, paulus@samba.org, npiggin@gmail.com, keescook@chromium.org, kernel-hardening@lists.openwall.com Cc: linux-kernel@vger.kernel.org, wangkefeng.wang@huawei.com, yebin10@huawei.com, thunder.leizhen@huawei.com, jingxiangfeng@huawei.com, fanchengyang@huawei.com References: <20190717080621.40424-1-yanaijie@huawei.com> <20190717080621.40424-9-yanaijie@huawei.com> From: Christophe Leroy Message-ID: Date: Mon, 29 Jul 2019 13:19:41 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190717080621.40424-9-yanaijie@huawei.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr Content-Transfer-Encoding: 8bit Le 17/07/2019 à 10:06, Jason Yan a écrit : > The original kernel still exists in the memory, clear it now. > > Signed-off-by: Jason Yan > Cc: Diana Craciun > Cc: Michael Ellerman > Cc: Christophe Leroy > Cc: Benjamin Herrenschmidt > Cc: Paul Mackerras > Cc: Nicholas Piggin > Cc: Kees Cook > --- > arch/powerpc/kernel/kaslr_booke.c | 11 +++++++++++ > arch/powerpc/mm/mmu_decl.h | 2 ++ > arch/powerpc/mm/nohash/fsl_booke.c | 1 + > 3 files changed, 14 insertions(+) > > diff --git a/arch/powerpc/kernel/kaslr_booke.c b/arch/powerpc/kernel/kaslr_booke.c > index 90357f4bd313..00339c05879f 100644 > --- a/arch/powerpc/kernel/kaslr_booke.c > +++ b/arch/powerpc/kernel/kaslr_booke.c > @@ -412,3 +412,14 @@ notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size) > > reloc_kernel_entry(dt_ptr, kimage_vaddr); > } > + > +void __init kaslr_second_init(void) > +{ > + /* If randomized, clear the original kernel */ > + if (kimage_vaddr != KERNELBASE) { > + unsigned long kernel_sz; > + > + kernel_sz = (unsigned long)_end - kimage_vaddr; > + memset((void *)KERNELBASE, 0, kernel_sz); Why are we clearing ? Is that just to tidy up or is it of security importance ? If so, maybe memzero_explicit() should be used instead ? > + } > +} > diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h > index 754ae1e69f92..9912ee598f9b 100644 > --- a/arch/powerpc/mm/mmu_decl.h > +++ b/arch/powerpc/mm/mmu_decl.h > @@ -150,8 +150,10 @@ extern void loadcam_multi(int first_idx, int num, int tmp_idx); > > #ifdef CONFIG_RANDOMIZE_BASE > extern void kaslr_early_init(void *dt_ptr, phys_addr_t size); > +extern void kaslr_second_init(void); No new 'extern' please. > #else > static inline void kaslr_early_init(void *dt_ptr, phys_addr_t size) {} > +static inline void kaslr_second_init(void) {} > #endif > > struct tlbcam { > diff --git a/arch/powerpc/mm/nohash/fsl_booke.c b/arch/powerpc/mm/nohash/fsl_booke.c > index 8d25a8dc965f..fa5a87f5c08e 100644 > --- a/arch/powerpc/mm/nohash/fsl_booke.c > +++ b/arch/powerpc/mm/nohash/fsl_booke.c > @@ -269,6 +269,7 @@ notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start) > kernstart_addr = start; > if (is_second_reloc) { > virt_phys_offset = PAGE_OFFSET - memstart_addr; > + kaslr_second_init(); > return; > } > > Christophe 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=-8.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 BE810C7618B for ; Mon, 29 Jul 2019 11:22:01 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3B62B20C01 for ; Mon, 29 Jul 2019 11:22:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=c-s.fr header.i=@c-s.fr header.b="TuKAFDEk" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3B62B20C01 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=c-s.fr Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 45xy2G2rRjzDqHl for ; Mon, 29 Jul 2019 21:21:58 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=c-s.fr (client-ip=93.17.236.30; helo=pegase1.c-s.fr; envelope-from=christophe.leroy@c-s.fr; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=c-s.fr Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=c-s.fr header.i=@c-s.fr header.b="TuKAFDEk"; dkim-atps=neutral Received: from pegase1.c-s.fr (pegase1.c-s.fr [93.17.236.30]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 45xxzj2bzKzDqJH for ; Mon, 29 Jul 2019 21:19:45 +1000 (AEST) Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 45xxzY2pwCz9txkm; Mon, 29 Jul 2019 13:19:37 +0200 (CEST) Authentication-Results: localhost; dkim=pass reason="1024-bit key; insecure key" header.d=c-s.fr header.i=@c-s.fr header.b=TuKAFDEk; dkim-adsp=pass; dkim-atps=neutral X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id GAawApQoOfH4; Mon, 29 Jul 2019 13:19:37 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 45xxzY1jWwz9txkl; Mon, 29 Jul 2019 13:19:37 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=c-s.fr; s=mail; t=1564399177; bh=QYn92bFk6L4jrJrPT8nEs5INqQRWowzslhlMsgOiPSA=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=TuKAFDEk1hkgNToNlN1eyQg4AAiN/y1nVzlhzB0UZjlCHyoJfk1bRt9tsfHx07rru Ye3bk/tGrBW405QYUU/vw3jlDklTgk6hMg3OYxx4FDU1BAagcqk91VnBNBE4wkesOj FIemEP+b6tkJ5Jx0o4UzuS769fA7CLCTTSDaerQM= Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 1EDB98B7CE; Mon, 29 Jul 2019 13:19:42 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id oGhuO4e1JRma; Mon, 29 Jul 2019 13:19:42 +0200 (CEST) Received: from [172.25.230.101] (po15451.idsi0.si.c-s.fr [172.25.230.101]) by messagerie.si.c-s.fr (Postfix) with ESMTP id D966D8B7B3; Mon, 29 Jul 2019 13:19:41 +0200 (CEST) Subject: Re: [RFC PATCH 08/10] powerpc/fsl_booke/kaslr: clear the original kernel if randomized To: Jason Yan , mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org, diana.craciun@nxp.com, benh@kernel.crashing.org, paulus@samba.org, npiggin@gmail.com, keescook@chromium.org, kernel-hardening@lists.openwall.com References: <20190717080621.40424-1-yanaijie@huawei.com> <20190717080621.40424-9-yanaijie@huawei.com> From: Christophe Leroy Message-ID: Date: Mon, 29 Jul 2019 13:19:41 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190717080621.40424-9-yanaijie@huawei.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr Content-Transfer-Encoding: 8bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: wangkefeng.wang@huawei.com, linux-kernel@vger.kernel.org, jingxiangfeng@huawei.com, thunder.leizhen@huawei.com, fanchengyang@huawei.com, yebin10@huawei.com Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Le 17/07/2019 à 10:06, Jason Yan a écrit : > The original kernel still exists in the memory, clear it now. > > Signed-off-by: Jason Yan > Cc: Diana Craciun > Cc: Michael Ellerman > Cc: Christophe Leroy > Cc: Benjamin Herrenschmidt > Cc: Paul Mackerras > Cc: Nicholas Piggin > Cc: Kees Cook > --- > arch/powerpc/kernel/kaslr_booke.c | 11 +++++++++++ > arch/powerpc/mm/mmu_decl.h | 2 ++ > arch/powerpc/mm/nohash/fsl_booke.c | 1 + > 3 files changed, 14 insertions(+) > > diff --git a/arch/powerpc/kernel/kaslr_booke.c b/arch/powerpc/kernel/kaslr_booke.c > index 90357f4bd313..00339c05879f 100644 > --- a/arch/powerpc/kernel/kaslr_booke.c > +++ b/arch/powerpc/kernel/kaslr_booke.c > @@ -412,3 +412,14 @@ notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size) > > reloc_kernel_entry(dt_ptr, kimage_vaddr); > } > + > +void __init kaslr_second_init(void) > +{ > + /* If randomized, clear the original kernel */ > + if (kimage_vaddr != KERNELBASE) { > + unsigned long kernel_sz; > + > + kernel_sz = (unsigned long)_end - kimage_vaddr; > + memset((void *)KERNELBASE, 0, kernel_sz); Why are we clearing ? Is that just to tidy up or is it of security importance ? If so, maybe memzero_explicit() should be used instead ? > + } > +} > diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h > index 754ae1e69f92..9912ee598f9b 100644 > --- a/arch/powerpc/mm/mmu_decl.h > +++ b/arch/powerpc/mm/mmu_decl.h > @@ -150,8 +150,10 @@ extern void loadcam_multi(int first_idx, int num, int tmp_idx); > > #ifdef CONFIG_RANDOMIZE_BASE > extern void kaslr_early_init(void *dt_ptr, phys_addr_t size); > +extern void kaslr_second_init(void); No new 'extern' please. > #else > static inline void kaslr_early_init(void *dt_ptr, phys_addr_t size) {} > +static inline void kaslr_second_init(void) {} > #endif > > struct tlbcam { > diff --git a/arch/powerpc/mm/nohash/fsl_booke.c b/arch/powerpc/mm/nohash/fsl_booke.c > index 8d25a8dc965f..fa5a87f5c08e 100644 > --- a/arch/powerpc/mm/nohash/fsl_booke.c > +++ b/arch/powerpc/mm/nohash/fsl_booke.c > @@ -269,6 +269,7 @@ notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start) > kernstart_addr = start; > if (is_second_reloc) { > virt_phys_offset = PAGE_OFFSET - memstart_addr; > + kaslr_second_init(); > return; > } > > Christophe