From nobody Mon Jun 22 22:48:34 2026 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 61E6BC4332F for ; Tue, 15 Mar 2022 13:28:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348671AbiCONaA (ORCPT ); Tue, 15 Mar 2022 09:30:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42468 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348657AbiCON3z (ORCPT ); Tue, 15 Mar 2022 09:29:55 -0400 Received: from hust.edu.cn (mail.hust.edu.cn [202.114.0.240]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4071C46B22 for ; Tue, 15 Mar 2022 06:28:40 -0700 (PDT) Received: from localhost.localdomain ([10.11.68.233]) (user=dzm91@hust.edu.cn mech=LOGIN bits=0) by mx1.hust.edu.cn with ESMTP id 22FDSG1u003439-22FDSG1x003439 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NO); Tue, 15 Mar 2022 21:28:20 +0800 From: Dongliang Mu To: Gao Xiang , Chao Yu Cc: Dongliang Mu , linux-erofs@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: [PATCH] fs: erofs: add sanity check for kobject in erofs_unregister_sysfs Date: Tue, 15 Mar 2022 21:28:14 +0800 Message-Id: <20220315132814.12332-1-dzm91@hust.edu.cn> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FEAS-AUTH-USER: dzm91@hust.edu.cn Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Dongliang Mu Syzkaller hit 'WARNING: kobject bug in erofs_unregister_sysfs'. This bug is triggered by injecting fault in kobject_init_and_add of erofs_unregister_sysfs. Fix this by adding sanity check for kobject in erofs_unregister_sysfs Note that I've tested the patch and the crash does not occur any more. Signed-off-by: Dongliang Mu Reviewed-by: Chao Yu Reviewed-by: Gao Xiang --- fs/erofs/sysfs.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/fs/erofs/sysfs.c b/fs/erofs/sysfs.c index dac252bc9228..f3babf1e6608 100644 --- a/fs/erofs/sysfs.c +++ b/fs/erofs/sysfs.c @@ -221,9 +221,11 @@ void erofs_unregister_sysfs(struct super_block *sb) { struct erofs_sb_info *sbi =3D EROFS_SB(sb); =20 - kobject_del(&sbi->s_kobj); - kobject_put(&sbi->s_kobj); - wait_for_completion(&sbi->s_kobj_unregister); + if (sbi->s_kobj.state_in_sysfs) { + kobject_del(&sbi->s_kobj); + kobject_put(&sbi->s_kobj); + wait_for_completion(&sbi->s_kobj_unregister); + } } =20 int __init erofs_init_sysfs(void) --=20 2.25.1