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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5A6FAC433F5 for ; Thu, 14 Apr 2022 17:27:03 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E71786B0071; Thu, 14 Apr 2022 13:27:02 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E20916B0074; Thu, 14 Apr 2022 13:27:02 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D0FFA6B0078; Thu, 14 Apr 2022 13:27:02 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.a.hostedemail.com [64.99.140.24]) by kanga.kvack.org (Postfix) with ESMTP id C1E886B0071 for ; Thu, 14 Apr 2022 13:27:02 -0400 (EDT) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id A21CC274E1 for ; Thu, 14 Apr 2022 17:27:02 +0000 (UTC) X-FDA: 79356165084.19.C442F28 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf13.hostedemail.com (Postfix) with ESMTP id 13A5920005 for ; Thu, 14 Apr 2022 17:27:01 +0000 (UTC) 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 1CA09620D8; Thu, 14 Apr 2022 17:27:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9BFD2C385A5; Thu, 14 Apr 2022 17:26:59 +0000 (UTC) Date: Thu, 14 Apr 2022 18:26:56 +0100 From: Catalin Marinas To: Patrick Wang Cc: akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm: kmemleak: take a full lowmem check in kmemleak_*_phys() Message-ID: References: <20220413122925.33856-1-patrick.wang.shcn@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220413122925.33856-1-patrick.wang.shcn@gmail.com> Authentication-Results: imf13.hostedemail.com; dkim=none; dmarc=fail reason="SPF not aligned (relaxed), No valid DKIM" header.from=arm.com (policy=none); spf=pass (imf13.hostedemail.com: domain of cmarinas@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=cmarinas@kernel.org X-Stat-Signature: rh39x7u1uqmuyxop7xbr1wcjzpco8uws X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 13A5920005 X-HE-Tag: 1649957221-38255 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Apr 13, 2022 at 08:29:25PM +0800, Patrick Wang wrote: > The kmemleak_*_phys() apis do not check the address for lowmem's min > boundary, while the caller may pass an address below lowmem, which > will trigger an oops: > > # echo scan > /sys/kernel/debug/kmemleak > [ 54.888353] Unable to handle kernel paging request at virtual address ff5fffffffe00000 > [ 54.888932] Oops [#1] > [ 54.889102] Modules linked in: > [ 54.889326] CPU: 2 PID: 134 Comm: bash Not tainted 5.18.0-rc1-next-20220407 #33 > [ 54.889620] Hardware name: riscv-virtio,qemu (DT) > [ 54.889901] epc : scan_block+0x74/0x15c > [ 54.890215] ra : scan_block+0x72/0x15c > [ 54.890390] epc : ffffffff801e5806 ra : ffffffff801e5804 sp : ff200000104abc30 > [ 54.890607] gp : ffffffff815cd4e8 tp : ff60000004cfa340 t0 : 0000000000000200 > [ 54.890835] t1 : 00aaaaaac23954cc t2 : 00000000000003ff s0 : ff200000104abc90 > [ 54.891024] s1 : ffffffff81b0ff28 a0 : 0000000000000000 a1 : ff5fffffffe01000 > [ 54.891201] a2 : ffffffff81b0ff28 a3 : 0000000000000002 a4 : 0000000000000001 > [ 54.891377] a5 : 0000000000000000 a6 : ff200000104abd7c a7 : 0000000000000005 > [ 54.891552] s2 : ff5fffffffe00ff9 s3 : ffffffff815cd998 s4 : ffffffff815d0e90 > [ 54.891727] s5 : ffffffff81b0ff28 s6 : 0000000000000020 s7 : ffffffff815d0eb0 > [ 54.891903] s8 : ffffffffffffffff s9 : ff5fffffffe00000 s10: ff5fffffffe01000 > [ 54.892078] s11: 0000000000000022 t3 : 00ffffffaa17db4c t4 : 000000000000000f > [ 54.892271] t5 : 0000000000000001 t6 : 0000000000000000 > [ 54.892408] status: 0000000000000100 badaddr: ff5fffffffe00000 cause: 000000000000000d > [ 54.892643] [] scan_gray_list+0x12e/0x1a6 > [ 54.892824] [] kmemleak_scan+0x2aa/0x57e > [ 54.892961] [] kmemleak_write+0x32a/0x40c > [ 54.893096] [] full_proxy_write+0x56/0x82 > [ 54.893235] [] vfs_write+0xa6/0x2a6 > [ 54.893362] [] ksys_write+0x6c/0xe2 > [ 54.893487] [] sys_write+0x22/0x2a > [ 54.893609] [] ret_from_syscall+0x0/0x2 Acked-by: Catalin Marinas