From patchwork Thu Sep 14 08:08:33 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Haibo Li X-Patchwork-Id: 13384777 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 71BB9EDE990 for ; Thu, 14 Sep 2023 08:09:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type: Content-Transfer-Encoding:MIME-Version:Message-ID:Date:Subject:CC:To:From: Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender :Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=mlOEeXuSL3Jd9KWoAGMasqY7uUX1ru96a24IVEsPgXk=; b=d6aJPx8X3ZhPtTy15K98qM9TeW bqDkhkQDIQtezM3g6qFx0VA59F9n7gws6nDc7Lp2n6RzE5JLueKtAWGsEpYnkEEk1Q70WZJDZkRBL CMHmuB8ntI3fg6wGMOHlsKq2vHf5+xcOvoo10KKW0IT5nOVGa2IQvstvpE1MmJ21B1PRltz8k3RGP U4k/g/ao72ilTRnHJC9Gi9UdCexcoM52qn6q4V50xu5YDkcFKQe0/U+Glp/8C8jIzDoc6g1YToadY pGAwBLfln0fEdc/pwWV1mARufLJOHmIaP1xbaRDV4cH+buvmgKOqBuEjPFJiMA9HHUDNZ0ZEdRZLa yd2PIpNg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qghPN-007f5a-0w; Thu, 14 Sep 2023 08:09:05 +0000 Received: from mailgw02.mediatek.com ([216.200.240.185]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qghPK-007f2K-10; Thu, 14 Sep 2023 08:09:03 +0000 X-UUID: f1efcb1c52d511ee86758d4a7c00f3a0-20230914 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=mediatek.com; s=dk; h=Content-Type:Content-Transfer-Encoding:MIME-Version:Message-ID:Date:Subject:CC:To:From; bh=mlOEeXuSL3Jd9KWoAGMasqY7uUX1ru96a24IVEsPgXk=; b=nbN5kH2ZHeBSmRDbusxGl/9eZ7H7OM8VxEjN4Ceca7hkyiE0CFGeQkeuunWg5eIxbwkPkmeufwzTexRgUinXlwQ7jnxFzPWvyYuJLwqC/Lu3A8Lec/y8ZBCSLi0HkNR5XSRzUt5nmpMC2GJwBAABc2a32vq8tNsraXzIPxgHiVg=; X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.1.31,REQID:d9c1bb89-a0b9-41d5-abb9-5a5aca5353d4,IP:0,U RL:0,TC:0,Content:0,EDM:0,RT:0,SF:0,FILE:0,BULK:0,RULE:Release_Ham,ACTION: release,TS:0 X-CID-META: VersionHash:0ad78a4,CLOUDID:ab31ee13-4929-4845-9571-38c601e9c3c9,B ulkID:nil,BulkQuantity:0,Recheck:0,SF:102,TC:nil,Content:0,EDM:-3,IP:nil,U RL:11|1,File:nil,Bulk:nil,QS:nil,BEC:nil,COL:0,OSI:0,OSA:0,AV:0,LES:1,SPR: NO,DKR:0,DKP:0,BRR:0,BRE:0 X-CID-BVR: 0,NGT X-CID-BAS: 0,NGT,0,_ X-CID-FACTOR: TF_CID_SPAM_SNR,TF_CID_SPAM_ULN X-UUID: f1efcb1c52d511ee86758d4a7c00f3a0-20230914 Received: from mtkmbs11n1.mediatek.inc [(172.21.101.185)] by mailgw02.mediatek.com (envelope-from ) (musrelay.mediatek.com ESMTP with TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384 256/256) with ESMTP id 805472291; Thu, 14 Sep 2023 01:08:53 -0700 Received: from mtkmbs13n1.mediatek.inc (172.21.101.193) by mtkmbs11n1.mediatek.inc (172.21.101.185) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.26; Thu, 14 Sep 2023 16:08:35 +0800 Received: from mszsdtlt101.gcn.mediatek.inc (10.16.4.141) by mtkmbs13n1.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.2.1118.26 via Frontend Transport; Thu, 14 Sep 2023 16:08:34 +0800 From: Haibo Li To: CC: , Andrey Ryabinin , Alexander Potapenko , Andrey Konovalov , Dmitry Vyukov , Vincenzo Frascino , Andrew Morton , Matthias Brugger , AngeloGioacchino Del Regno , , , , , Haibo Li Subject: [PATCH] kasan:fix access invalid shadow address when input is illegal Date: Thu, 14 Sep 2023 16:08:33 +0800 Message-ID: <20230914080833.50026-1-haibo.li@mediatek.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-MTK: N X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230914_010902_373086_54F3D7B6 X-CRM114-Status: GOOD ( 14.03 ) X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org when the input address is illegal,the corresponding shadow address from kasan_mem_to_shadow may have no mapping in mmu table. Access such shadow address causes kernel oops. Here is a sample about oops on arm64(VA 39bit) with KASAN_SW_TAGS on: [ffffffb80aaaaaaa] pgd=000000005d3ce003, p4d=000000005d3ce003, pud=000000005d3ce003, pmd=0000000000000000 Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP Modules linked in: CPU: 3 PID: 100 Comm: sh Not tainted 6.6.0-rc1-dirty #43 Hardware name: linux,dummy-virt (DT) pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : __hwasan_load8_noabort+0x5c/0x90 lr : do_ib_ob+0xf4/0x110 ffffffb80aaaaaaa is the shadow address for efffff80aaaaaaaa. The problem is reading invalid shadow in kasan_check_range. The generic kasan also has similar oops. To fix it,check shadow address by reading it with no fault. After this patch,KASAN is able to report invalid memory access for this case. Signed-off-by: Haibo Li --- mm/kasan/kasan.h | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index f70e3d7a602e..bd30f35e18b2 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -304,8 +304,17 @@ static __always_inline bool addr_has_metadata(const void *addr) #ifdef __HAVE_ARCH_SHADOW_MAP return (kasan_mem_to_shadow((void *)addr) != NULL); #else - return (kasan_reset_tag(addr) >= - kasan_shadow_to_mem((void *)KASAN_SHADOW_START)); + u8 *shadow, shadow_val; + + if (kasan_reset_tag(addr) < + kasan_shadow_to_mem((void *)KASAN_SHADOW_START)) + return false; + /* use read with nofault to check whether the shadow is accessible */ + shadow = kasan_mem_to_shadow((void *)addr); + __get_kernel_nofault(&shadow_val, shadow, u8, fault); + return true; +fault: + return false; #endif }