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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 448AAC4332F for ; Tue, 5 Apr 2022 08:01:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234475AbiDEH6g (ORCPT ); Tue, 5 Apr 2022 03:58:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34262 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233108AbiDEHr2 (ORCPT ); Tue, 5 Apr 2022 03:47:28 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1957B972FF; Tue, 5 Apr 2022 00:43:39 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 72172616C4; Tue, 5 Apr 2022 07:43:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5E033C340EE; Tue, 5 Apr 2022 07:43:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649144617; bh=5GLxWDCGq3Rzt274EPTNttgW7QLApZtJxsJNkrorsb0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HYP722hdm2tn3PB4Rwf++Uvp2N7uHs6BCiBCjA77mR75yQqpL+Dq3l1VjuAnp4Nq7 GGQ8sjlAE4tp34HaSl/a3QEtxfuX85T20DUS5sXCh/qzQ9vaW40Ao26tyI/n7IOWCr OCwBaYVDSo8DiaxwVzfvOgcV14TgCZLTGOljY8hA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kuan-Ying Lee , Catalin Marinas , Matthias Brugger , Chinwen Chang , Nicholas Tang , Yee Lee , Andrew Morton , Linus Torvalds Subject: [PATCH 5.17 0110/1126] mm/kmemleak: reset tag when compare object pointer Date: Tue, 5 Apr 2022 09:14:17 +0200 Message-Id: <20220405070410.800091508@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220405070407.513532867@linuxfoundation.org> References: <20220405070407.513532867@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Kuan-Ying Lee commit bfc8089f00fa526dea983844c880fa8106c33ac4 upstream. 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. kmemleak: [name:kmemleak&]Scan area larger than object 0xffffffe77076f440 CPU: 4 PID: 1 Comm: init Tainted: G S W 5.15.25-android13-0-g5cacf919c2bc #1 Hardware name: MT6983(ENG) (DT) Call trace: add_scan_area+0xc4/0x244 kmemleak_scan_area+0x40/0x9c layout_and_allocate+0x1e8/0x288 load_module+0x2c8/0xf00 __se_sys_finit_module+0x190/0x1d0 __arm64_sys_finit_module+0x20/0x30 invoke_syscall+0x60/0x170 el0_svc_common+0xc8/0x114 do_el0_svc+0x28/0xa0 el0_svc+0x60/0xf8 el0t_64_sync_handler+0x88/0xec el0t_64_sync+0x1b4/0x1b8 kmemleak: [name:kmemleak&]Object 0xf5ffffe77076b000 (size 32768): kmemleak: [name:kmemleak&] comm "init", pid 1, jiffies 4294894197 kmemleak: [name:kmemleak&] min_count = 0 kmemleak: [name:kmemleak&] count = 0 kmemleak: [name:kmemleak&] flags = 0x1 kmemleak: [name:kmemleak&] checksum = 0 kmemleak: [name:kmemleak&] backtrace: module_alloc+0x9c/0x120 move_module+0x34/0x19c layout_and_allocate+0x1c4/0x288 load_module+0x2c8/0xf00 __se_sys_finit_module+0x190/0x1d0 __arm64_sys_finit_module+0x20/0x30 invoke_syscall+0x60/0x170 el0_svc_common+0xc8/0x114 do_el0_svc+0x28/0xa0 el0_svc+0x60/0xf8 el0t_64_sync_handler+0x88/0xec el0t_64_sync+0x1b4/0x1b8 Link: https://lkml.kernel.org/r/20220318034051.30687-1-Kuan-Ying.Lee@mediatek.com Signed-off-by: Kuan-Ying Lee Reviewed-by: Catalin Marinas Cc: Matthias Brugger Cc: Chinwen Chang Cc: Nicholas Tang Cc: Yee Lee Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/kmemleak.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -796,6 +796,8 @@ static void add_scan_area(unsigned long unsigned long flags; struct kmemleak_object *object; struct kmemleak_scan_area *area = NULL; + unsigned long untagged_ptr; + unsigned long untagged_objp; object = find_and_get_object(ptr, 1); if (!object) { @@ -804,6 +806,9 @@ static void add_scan_area(unsigned long return; } + untagged_ptr = (unsigned long)kasan_reset_tag((void *)ptr); + untagged_objp = (unsigned long)kasan_reset_tag((void *)object->pointer); + if (scan_area_cache) area = kmem_cache_alloc(scan_area_cache, gfp_kmemleak_mask(gfp)); @@ -815,8 +820,8 @@ static void add_scan_area(unsigned long goto out_unlock; } if (size == SIZE_MAX) { - size = object->pointer + object->size - ptr; - } else if (ptr + size > object->pointer + object->size) { + size = 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);