From nobody Sun Sep 22 05:35:09 2024 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 14691C433EF for ; Fri, 18 Mar 2022 03:41:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232242AbiCRDmd (ORCPT ); Thu, 17 Mar 2022 23:42:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59642 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232220AbiCRDmZ (ORCPT ); Thu, 17 Mar 2022 23:42:25 -0400 Received: from mailgw01.mediatek.com (unknown [60.244.123.138]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E8957275479 for ; Thu, 17 Mar 2022 20:41:01 -0700 (PDT) X-UUID: b032444fbdc44c659a7123fe95de19ea-20220318 X-UUID: b032444fbdc44c659a7123fe95de19ea-20220318 Received: from mtkmbs10n2.mediatek.inc [(172.21.101.183)] by mailgw01.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384 256/256) with ESMTP id 462894881; Fri, 18 Mar 2022 11:40:57 +0800 Received: from mtkcas11.mediatek.inc (172.21.101.40) by mtkmbs10n1.mediatek.inc (172.21.101.34) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.2.792.15; Fri, 18 Mar 2022 11:40:56 +0800 Received: from mtksdccf07.mediatek.inc (172.21.84.99) by mtkcas11.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Fri, 18 Mar 2022 11:40:56 +0800 From: Kuan-Ying Lee To: Catalin Marinas , Andrew Morton , Matthias Brugger CC: , , , Kuan-Ying Lee , , , , Subject: [PATCH] mm/kmemleak: Reset tag when compare object pointer Date: Fri, 18 Mar 2022 11:40:48 +0800 Message-ID: <20220318034051.30687-1-Kuan-Ying.Lee@mediatek.com> X-Mailer: git-send-email 2.18.0 MIME-Version: 1.0 X-MTK: N Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" When we use HW-tag based kasan and enable vmalloc support, we hit the following bug. It is due to comparison between tagged object and non-tagged pointer. We need to reset the kasan tag when we need to compare tagged object and non-tagged pointer. [ 7.690429][T400001] init: kmemleak: [name:kmemleak&]Scan area larger th= an object 0xffffffe77076f440 [ 7.691762][T400001] init: CPU: 4 PID: 1 Comm: init Tainted: G S W = 5.15.25-android13-0-g5cacf919c2bc #1 [ 7.693218][T400001] init: Hardware name: MT6983(ENG) (DT) [ 7.693983][T400001] init: Call trace: [ 7.694508][T400001] init: dump_backtrace.cfi_jt+0x0/0x8 [ 7.695272][T400001] init: dump_stack_lvl+0xac/0x120 [ 7.695985][T400001] init: add_scan_area+0xc4/0x244 [ 7.696685][T400001] init: kmemleak_scan_area+0x40/0x9c [ 7.697428][T400001] init: layout_and_allocate+0x1e8/0x288 [ 7.698211][T400001] init: load_module+0x2c8/0xf00 [ 7.698895][T400001] init: __se_sys_finit_module+0x190/0x1d0 [ 7.699701][T400001] init: __arm64_sys_finit_module+0x20/0x30 [ 7.700517][T400001] init: invoke_syscall+0x60/0x170 [ 7.701225][T400001] init: el0_svc_common+0xc8/0x114 [ 7.701933][T400001] init: do_el0_svc+0x28/0xa0 [ 7.702580][T400001] init: el0_svc+0x60/0xf8 [ 7.703196][T400001] init: el0t_64_sync_handler+0x88/0xec [ 7.703964][T400001] init: el0t_64_sync+0x1b4/0x1b8 [ 7.704658][T400001] init: kmemleak: [name:kmemleak&]Object 0xf5ffffe770= 76b000 (size 32768): [ 7.705824][T400001] init: kmemleak: [name:kmemleak&] comm "init", pid = 1, jiffies 4294894197 [ 7.707002][T400001] init: kmemleak: [name:kmemleak&] min_count =3D 0 [ 7.707886][T400001] init: kmemleak: [name:kmemleak&] count =3D 0 [ 7.708718][T400001] init: kmemleak: [name:kmemleak&] flags =3D 0x1 [ 7.709574][T400001] init: kmemleak: [name:kmemleak&] checksum =3D 0 [ 7.710440][T400001] init: kmemleak: [name:kmemleak&] backtrace: [ 7.711284][T400001] init: module_alloc+0x9c/0x120 [ 7.712015][T400001] init: move_module+0x34/0x19c [ 7.712735][T400001] init: layout_and_allocate+0x1c4/0x288 [ 7.713561][T400001] init: load_module+0x2c8/0xf00 [ 7.714291][T400001] init: __se_sys_finit_module+0x190/0x1d0 [ 7.715142][T400001] init: __arm64_sys_finit_module+0x20/0x30 [ 7.716004][T400001] init: invoke_syscall+0x60/0x170 [ 7.716758][T400001] init: el0_svc_common+0xc8/0x114 [ 7.717512][T400001] init: do_el0_svc+0x28/0xa0 [ 7.718207][T400001] init: el0_svc+0x60/0xf8 [ 7.718869][T400001] init: el0t_64_sync_handler+0x88/0xec [ 7.719683][T400001] init: el0t_64_sync+0x1b4/0x1b8 Signed-off-by: Kuan-Ying Lee Reviewed-by: Catalin Marinas --- mm/kmemleak.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 7580baa76af1..acd7cbb82e16 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -796,6 +796,8 @@ static void add_scan_area(unsigned long ptr, size_t siz= e, gfp_t gfp) unsigned long flags; struct kmemleak_object *object; struct kmemleak_scan_area *area =3D NULL; + unsigned long untagged_ptr; + unsigned long untagged_objp; =20 object =3D find_and_get_object(ptr, 1); if (!object) { @@ -804,6 +806,9 @@ static void add_scan_area(unsigned long ptr, size_t siz= e, gfp_t gfp) return; } =20 + untagged_ptr =3D (unsigned long)kasan_reset_tag((void *)ptr); + untagged_objp =3D (unsigned long)kasan_reset_tag((void *)object->pointer); + if (scan_area_cache) area =3D kmem_cache_alloc(scan_area_cache, gfp_kmemleak_mask(gfp)); =20 @@ -815,8 +820,8 @@ static void add_scan_area(unsigned long ptr, size_t siz= e, gfp_t gfp) goto out_unlock; } if (size =3D=3D SIZE_MAX) { - size =3D object->pointer + object->size - ptr; - } else if (ptr + size > object->pointer + object->size) { + size =3D untagged_objp + object->size - untagged_ptr; + } else if (untagged_ptr + size > untagged_objp + object->size) { kmemleak_warn("Scan area larger than object 0x%08lx\n", ptr); dump_object_info(object); kmem_cache_free(scan_area_cache, area); --=20 2.18.0