From patchwork Sat Jul 29 20:37:31 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: SeongJae Park X-Patchwork-Id: 13333209 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 120B5C04A6A for ; Sat, 29 Jul 2023 20:37:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229481AbjG2Uhl (ORCPT ); Sat, 29 Jul 2023 16:37:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60062 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229379AbjG2Uhk (ORCPT ); Sat, 29 Jul 2023 16:37:40 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BDC5AC7; Sat, 29 Jul 2023 13:37:38 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 4A4476027E; Sat, 29 Jul 2023 20:37:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D8B73C433C7; Sat, 29 Jul 2023 20:37:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1690663057; bh=iMknI2mssvMpvNEEtPFsjpKnh0+OEHxOEdyJZpeCgHY=; h=From:To:Cc:Subject:Date:From; b=vFJySY2rk1//Bkt9H41fBKeJvOhjKt9m7pNLfcYd/YbXNoDwBUj2HavpAFun6VP8b fpqIbkQKa9JyY+9FArMVz3l5JUe+ji6L2OwZA4tOjXV8DBcT53kkP+kdJN+7rnGOgJ OHMq25YIkjtAIVhX71U9KccUySxnQwKh+gOANdDqlB+MqQ2dzQ9CwGpfpDGTdumfsq yVynLsLCQiJ3nHfOvA3dswClNDRjCrA4gGnrJ1mf5h5HnSXLHqmKThXGFP4U9BVWgG XP18+zQi8wTYIR2MG3bVK9SM43+WIrj2jk9NogyN69sz8qGzCSgQOHGmuOiqiWslzu Nq/Xps6fD3aVQ== From: SeongJae Park To: Andrew Morton Cc: SeongJae Park , Brendan Higgins , damon@lists.linux.dev, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, kunit-dev@googlegroups.com, stable@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 0/2] mm/damon/core: fix unitialized memory error from Date: Sat, 29 Jul 2023 20:37:31 +0000 Message-Id: <20230729203733.38949-1-sj@kernel.org> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org damos_new_filter() is returning a damos_filter struct without initializing its ->list field. And the users of the function uses the struct without initializing the field. As a result, uninitialized memory access error is possible. Actually, a kernel NULL pointer dereference BUG can be triggered using DAMON user-space tool, like below. # damo start --damos_action stat --damos_filter anon matching # damo tune --damos_action stat --damos_filter anon matching --damos_filter anon nomatching # dmesg [...] [ 36.908136] BUG: kernel NULL pointer dereference, address: 0000000000000008 [ 36.910483] #PF: supervisor write access in kernel mode [ 36.912238] #PF: error_code(0x0002) - not-present page [ 36.913415] PGD 0 P4D 0 [ 36.913978] Oops: 0002 [#1] PREEMPT SMP PTI [ 36.914878] CPU: 32 PID: 1335 Comm: kdamond.0 Not tainted 6.5.0-rc3-mm-unstable-damon+ #1 [ 36.916621] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 [ 36.919051] RIP: 0010:damos_destroy_filter (include/linux/list.h:114 include/linux/list.h:137 include/linux/list.h:148 mm/damon/core.c:345 mm/damon/core.c:355) [...] [ 36.938247] Call Trace: [ 36.938721] [...] [ 36.950064] ? damos_destroy_filter (include/linux/list.h:114 include/linux/list.h:137 include/linux/list.h:148 mm/damon/core.c:345 mm/damon/core.c:355) [ 36.950883] ? damon_sysfs_set_scheme_filters.isra.0 (mm/damon/sysfs-schemes.c:1573) [ 36.952019] damon_sysfs_set_schemes (mm/damon/sysfs-schemes.c:1674 mm/damon/sysfs-schemes.c:1686) [ 36.952875] damon_sysfs_apply_inputs (mm/damon/sysfs.c:1312 mm/damon/sysfs.c:1298) [ 36.953757] ? damon_pa_check_accesses (mm/damon/paddr.c:168 mm/damon/paddr.c:179) [ 36.954648] damon_sysfs_cmd_request_callback (mm/damon/sysfs.c:1329 mm/damon/sysfs.c:1359) [...] The first patch of this patchset fixes the bug by initializing the field in damos_new_filter(). The second patch adds a unit test for the problem. Note that the second patch Cc stable@ without Fixes: tag, since it would be better to be ingested together for avoiding any future regression. SeongJae Park (2): mm/damon/core: initialize damo_filter->list from damos_new_filter() mm/damon/core-test: add a test for damos_new_filter() mm/damon/core-test.h | 13 +++++++++++++ mm/damon/core.c | 1 + 2 files changed, 14 insertions(+)