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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 688AEC432C0 for ; Thu, 21 Nov 2019 13:04:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4B6352089D for ; Thu, 21 Nov 2019 13:04:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726961AbfKUNEA (ORCPT ); Thu, 21 Nov 2019 08:04:00 -0500 Received: from relay.sw.ru ([185.231.240.75]:52106 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726293AbfKUND7 (ORCPT ); Thu, 21 Nov 2019 08:03:59 -0500 Received: from dhcp-172-16-25-5.sw.ru ([172.16.25.5]) by relay.sw.ru with esmtp (Exim 4.92.3) (envelope-from ) id 1iXm7i-0002DQ-S4; Thu, 21 Nov 2019 16:03:50 +0300 Subject: Re: [PATCH v4 1/2] kasan: detect negative size in memory operation function To: Walter Wu Cc: Alexander Potapenko , Dmitry Vyukov , Matthias Brugger , kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, wsd_upstream , linux-mediatek@lists.infradead.org References: <20191112065302.7015-1-walter-zh.wu@mediatek.com> <040479c3-6f96-91c6-1b1a-9f3e947dac06@virtuozzo.com> <1574341376.8338.4.camel@mtksdccf07> From: Andrey Ryabinin Message-ID: <217bd537-e6b7-3acc-b6bb-ac9c5d94da89@virtuozzo.com> Date: Thu, 21 Nov 2019 16:03:38 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: <1574341376.8338.4.camel@mtksdccf07> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/21/19 4:02 PM, Walter Wu wrote: > On Thu, 2019-11-21 at 15:26 +0300, Andrey Ryabinin wrote: >> >> On 11/12/19 9:53 AM, Walter Wu wrote: >> >>> diff --git a/mm/kasan/common.c b/mm/kasan/common.c >>> index 6814d6d6a023..4bfce0af881f 100644 >>> --- a/mm/kasan/common.c >>> +++ b/mm/kasan/common.c >>> @@ -102,7 +102,8 @@ EXPORT_SYMBOL(__kasan_check_write); >>> #undef memset >>> void *memset(void *addr, int c, size_t len) >>> { >>> - check_memory_region((unsigned long)addr, len, true, _RET_IP_); >>> + if (!check_memory_region((unsigned long)addr, len, true, _RET_IP_)) >>> + return NULL; >>> >>> return __memset(addr, c, len); >>> } >>> @@ -110,8 +111,9 @@ void *memset(void *addr, int c, size_t len) >>> #undef memmove >>> void *memmove(void *dest, const void *src, size_t len) >>> { >>> - check_memory_region((unsigned long)src, len, false, _RET_IP_); >>> - check_memory_region((unsigned long)dest, len, true, _RET_IP_); >>> + if (!check_memory_region((unsigned long)src, len, false, _RET_IP_) || >>> + !check_memory_region((unsigned long)dest, len, true, _RET_IP_)) >>> + return NULL; >>> >>> return __memmove(dest, src, len); >>> } >>> @@ -119,8 +121,9 @@ void *memmove(void *dest, const void *src, size_t len) >>> #undef memcpy >>> void *memcpy(void *dest, const void *src, size_t len) >>> { >>> - check_memory_region((unsigned long)src, len, false, _RET_IP_); >>> - check_memory_region((unsigned long)dest, len, true, _RET_IP_); >>> + if (!check_memory_region((unsigned long)src, len, false, _RET_IP_) || >>> + !check_memory_region((unsigned long)dest, len, true, _RET_IP_)) >>> + return NULL; >>> >> >> I realized that we are going a wrong direction here. Entirely skipping mem*() operation on any >> poisoned shadow value might only make things worse. Some bugs just don't have any serious consequences, >> but skipping the mem*() ops entirely might introduce such consequences, which wouldn't happen otherwise. >> >> So let's keep this code as this, no need to check the result of check_memory_region(). >> >> > Ok, we just need to determine whether size is negative number. If yes > then KASAN produce report and continue to execute mem*(). right? > Yes. 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=-5.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 AACA4C432C3 for ; Thu, 21 Nov 2019 13:03:58 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 7E48D2089D for ; Thu, 21 Nov 2019 13:03:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="lE7J00aB" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7E48D2089D Authentication-Results: mail.kernel.org; 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Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iXm7p-00069D-SZ; Thu, 21 Nov 2019 13:03:57 +0000 Received: from relay.sw.ru ([185.231.240.75]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1iXm7n-00068b-Ov; Thu, 21 Nov 2019 13:03:57 +0000 Received: from dhcp-172-16-25-5.sw.ru ([172.16.25.5]) by relay.sw.ru with esmtp (Exim 4.92.3) (envelope-from ) id 1iXm7i-0002DQ-S4; Thu, 21 Nov 2019 16:03:50 +0300 Subject: Re: [PATCH v4 1/2] kasan: detect negative size in memory operation function To: Walter Wu References: <20191112065302.7015-1-walter-zh.wu@mediatek.com> <040479c3-6f96-91c6-1b1a-9f3e947dac06@virtuozzo.com> <1574341376.8338.4.camel@mtksdccf07> From: Andrey Ryabinin Message-ID: <217bd537-e6b7-3acc-b6bb-ac9c5d94da89@virtuozzo.com> Date: Thu, 21 Nov 2019 16:03:38 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: <1574341376.8338.4.camel@mtksdccf07> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191121_050355_807642_59309202 X-CRM114-Status: GOOD ( 10.50 ) X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: wsd_upstream , linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, Alexander Potapenko , linux-arm-kernel@lists.infradead.org, Matthias Brugger , linux-mediatek@lists.infradead.org, Dmitry Vyukov Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org On 11/21/19 4:02 PM, Walter Wu wrote: > On Thu, 2019-11-21 at 15:26 +0300, Andrey Ryabinin wrote: >> >> On 11/12/19 9:53 AM, Walter Wu wrote: >> >>> diff --git a/mm/kasan/common.c b/mm/kasan/common.c >>> index 6814d6d6a023..4bfce0af881f 100644 >>> --- a/mm/kasan/common.c >>> +++ b/mm/kasan/common.c >>> @@ -102,7 +102,8 @@ EXPORT_SYMBOL(__kasan_check_write); >>> #undef memset >>> void *memset(void *addr, int c, size_t len) >>> { >>> - check_memory_region((unsigned long)addr, len, true, _RET_IP_); >>> + if (!check_memory_region((unsigned long)addr, len, true, _RET_IP_)) >>> + return NULL; >>> >>> return __memset(addr, c, len); >>> } >>> @@ -110,8 +111,9 @@ void *memset(void *addr, int c, size_t len) >>> #undef memmove >>> void *memmove(void *dest, const void *src, size_t len) >>> { >>> - check_memory_region((unsigned long)src, len, false, _RET_IP_); >>> - check_memory_region((unsigned long)dest, len, true, _RET_IP_); >>> + if (!check_memory_region((unsigned long)src, len, false, _RET_IP_) || >>> + !check_memory_region((unsigned long)dest, len, true, _RET_IP_)) >>> + return NULL; >>> >>> return __memmove(dest, src, len); >>> } >>> @@ -119,8 +121,9 @@ void *memmove(void *dest, const void *src, size_t len) >>> #undef memcpy >>> void *memcpy(void *dest, const void *src, size_t len) >>> { >>> - check_memory_region((unsigned long)src, len, false, _RET_IP_); >>> - check_memory_region((unsigned long)dest, len, true, _RET_IP_); >>> + if (!check_memory_region((unsigned long)src, len, false, _RET_IP_) || >>> + !check_memory_region((unsigned long)dest, len, true, _RET_IP_)) >>> + return NULL; >>> >> >> I realized that we are going a wrong direction here. Entirely skipping mem*() operation on any >> poisoned shadow value might only make things worse. Some bugs just don't have any serious consequences, >> but skipping the mem*() ops entirely might introduce such consequences, which wouldn't happen otherwise. >> >> So let's keep this code as this, no need to check the result of check_memory_region(). >> >> > Ok, we just need to determine whether size is negative number. If yes > then KASAN produce report and continue to execute mem*(). right? > Yes. _______________________________________________ Linux-mediatek mailing list Linux-mediatek@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-mediatek 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=-5.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, 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 E02BAC43215 for ; Thu, 21 Nov 2019 13:04:01 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 B6F38208A1 for ; Thu, 21 Nov 2019 13:04:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="fkDqGN9c" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B6F38208A1 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=virtuozzo.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date: Message-ID:From:References:To:Subject:Reply-To:Content-ID:Content-Description :Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=8wu38WfZEYKgtwHEKbxbFV3H+UEXUI9nzFXnR7ItQIM=; b=fkDqGN9cOz3sly mFgR/yXDQa2A5Kyz6jRfxzZl/ZZZlbe6mZY5i5y0nrQ6n1/+kUYRq6XmiBhqKLiT6YgrAPsmuz4mR JkNcZtVV0jlWmJSl1dUM9/Qs2dakoO1eKnTiFN22YUPVmsu7xm0OPNGOLc/Oqb3xtT5TDouXsQ9vY nvZjWHLDKdKWCujrW2I0i469rxd2vSS+Kt4ovB59gLGbCwZg5JC14M8gmP1Q+ZX9HvXAkx6mnQ8XE jDPATgIE7R7RR638t/RWCqj5Wtt+7/4edfAV4cUI+caVuo+7HZgnLVxo9Idn8ZMcnZhvJMP/iD4CO /nD4Pij+xsFlFRtJNsMQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iXm7q-00069r-Oc; Thu, 21 Nov 2019 13:03:58 +0000 Received: from relay.sw.ru ([185.231.240.75]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1iXm7n-00068b-Ov; Thu, 21 Nov 2019 13:03:57 +0000 Received: from dhcp-172-16-25-5.sw.ru ([172.16.25.5]) by relay.sw.ru with esmtp (Exim 4.92.3) (envelope-from ) id 1iXm7i-0002DQ-S4; Thu, 21 Nov 2019 16:03:50 +0300 Subject: Re: [PATCH v4 1/2] kasan: detect negative size in memory operation function To: Walter Wu References: <20191112065302.7015-1-walter-zh.wu@mediatek.com> <040479c3-6f96-91c6-1b1a-9f3e947dac06@virtuozzo.com> <1574341376.8338.4.camel@mtksdccf07> From: Andrey Ryabinin Message-ID: <217bd537-e6b7-3acc-b6bb-ac9c5d94da89@virtuozzo.com> Date: Thu, 21 Nov 2019 16:03:38 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: <1574341376.8338.4.camel@mtksdccf07> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191121_050355_807642_59309202 X-CRM114-Status: GOOD ( 10.50 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: wsd_upstream , linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, Alexander Potapenko , linux-arm-kernel@lists.infradead.org, Matthias Brugger , linux-mediatek@lists.infradead.org, Dmitry Vyukov Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 11/21/19 4:02 PM, Walter Wu wrote: > On Thu, 2019-11-21 at 15:26 +0300, Andrey Ryabinin wrote: >> >> On 11/12/19 9:53 AM, Walter Wu wrote: >> >>> diff --git a/mm/kasan/common.c b/mm/kasan/common.c >>> index 6814d6d6a023..4bfce0af881f 100644 >>> --- a/mm/kasan/common.c >>> +++ b/mm/kasan/common.c >>> @@ -102,7 +102,8 @@ EXPORT_SYMBOL(__kasan_check_write); >>> #undef memset >>> void *memset(void *addr, int c, size_t len) >>> { >>> - check_memory_region((unsigned long)addr, len, true, _RET_IP_); >>> + if (!check_memory_region((unsigned long)addr, len, true, _RET_IP_)) >>> + return NULL; >>> >>> return __memset(addr, c, len); >>> } >>> @@ -110,8 +111,9 @@ void *memset(void *addr, int c, size_t len) >>> #undef memmove >>> void *memmove(void *dest, const void *src, size_t len) >>> { >>> - check_memory_region((unsigned long)src, len, false, _RET_IP_); >>> - check_memory_region((unsigned long)dest, len, true, _RET_IP_); >>> + if (!check_memory_region((unsigned long)src, len, false, _RET_IP_) || >>> + !check_memory_region((unsigned long)dest, len, true, _RET_IP_)) >>> + return NULL; >>> >>> return __memmove(dest, src, len); >>> } >>> @@ -119,8 +121,9 @@ void *memmove(void *dest, const void *src, size_t len) >>> #undef memcpy >>> void *memcpy(void *dest, const void *src, size_t len) >>> { >>> - check_memory_region((unsigned long)src, len, false, _RET_IP_); >>> - check_memory_region((unsigned long)dest, len, true, _RET_IP_); >>> + if (!check_memory_region((unsigned long)src, len, false, _RET_IP_) || >>> + !check_memory_region((unsigned long)dest, len, true, _RET_IP_)) >>> + return NULL; >>> >> >> I realized that we are going a wrong direction here. Entirely skipping mem*() operation on any >> poisoned shadow value might only make things worse. Some bugs just don't have any serious consequences, >> but skipping the mem*() ops entirely might introduce such consequences, which wouldn't happen otherwise. >> >> So let's keep this code as this, no need to check the result of check_memory_region(). >> >> > Ok, we just need to determine whether size is negative number. If yes > then KASAN produce report and continue to execute mem*(). right? > Yes. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel