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 lists.sourceforge.net (lists.sourceforge.net [216.105.38.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D5445C4332F for ; Fri, 21 Oct 2022 07:26:30 +0000 (UTC) Received: from [127.0.0.1] (helo=sfs-ml-2.v29.lw.sourceforge.com) by sfs-ml-2.v29.lw.sourceforge.com with esmtp (Exim 4.95) (envelope-from ) id 1olmQG-0005V4-9n; Fri, 21 Oct 2022 07:26:28 +0000 Received: from [172.30.20.202] (helo=mx.sourceforge.net) by sfs-ml-2.v29.lw.sourceforge.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1olmQ6-0005Us-C0 for linux-f2fs-devel@lists.sourceforge.net; Fri, 21 Oct 2022 07:26:20 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: MIME-Version:Date:Message-ID:From:References:CC:To:Subject:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=JQluvds8xOLIlfimsEnEw6zA5CGTTtIL1qDb7SHY87g=; b=evwoLLe+vqNmc8l7fSRsh2TWVn 6YMcMTJZCc/0snoykKYKgXmr90q4CTnU+fL+TZ5cdrr9BYncWCl6h4CQszw/plKAgjBmtUfUW8QdM 3Zt2lG+rNaiTZdwsfKrdHXUvldHHyeruxQ0FPwsTkQbqMCIwTv/7wagmXMhATjmrO8xM=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:MIME-Version:Date: Message-ID:From:References:CC:To:Subject:Sender:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=JQluvds8xOLIlfimsEnEw6zA5CGTTtIL1qDb7SHY87g=; b=e6mks9PnqxTA0KqecAVxquNCzL ITsRl+tv+utbMEiHxDnOPUJaxwXkM+zCchN2w0IwUMrjMbvog/jJo3VC3d+CDoC+wTMGOSrrLMfpG iRCROrVIIricgJcHCmwqEK1XrAh/K7T/8EIxK2DhzliqPUofRwmXJNj7WEwltFJ+F7Sc=; Received: from szxga02-in.huawei.com ([45.249.212.188]) by sfi-mx-1.v28.lw.sourceforge.com with esmtps (TLS1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.95) id 1olmQ1-00Bsy5-P1 for linux-f2fs-devel@lists.sourceforge.net; Fri, 21 Oct 2022 07:26:18 +0000 Received: from dggpemm500024.china.huawei.com (unknown [172.30.72.54]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4Mtwr34fC2zVj5k; Fri, 21 Oct 2022 15:21:23 +0800 (CST) Received: from dggpemm500007.china.huawei.com (7.185.36.183) by dggpemm500024.china.huawei.com (7.185.36.203) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Fri, 21 Oct 2022 15:25:54 +0800 Received: from [10.174.178.174] (10.174.178.174) by dggpemm500007.china.huawei.com (7.185.36.183) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Fri, 21 Oct 2022 15:25:53 +0800 To: Luben Tuikov , , , , , , , References: <20221021022102.2231464-1-yangyingliang@huawei.com> Message-ID: <2a99c52c-d29c-5f5c-57a8-9851018e7420@huawei.com> Date: Fri, 21 Oct 2022 15:25:51 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-Originating-IP: [10.174.178.174] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpemm500007.china.huawei.com (7.185.36.183) X-CFilter-Loop: Reflected X-Headers-End: 1olmQ1-00Bsy5-P1 Subject: Re: [f2fs-dev] [PATCH 00/11] fix memory leak while kset_register() fails X-BeenThere: linux-f2fs-devel@lists.sourceforge.net X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Yang Yingliang via Linux-f2fs-devel Reply-To: Yang Yingliang Cc: alexander.deucher@amd.com, richard@nod.at, mst@redhat.com, gregkh@linuxfoundation.org, somlo@cmu.edu, liushixin2@huawei.com, joseph.qi@linux.alibaba.com, jlbec@evilplan.org, hsiangkao@linux.alibaba.com, rafael@kernel.org, jaegeuk@kernel.org, akpm@linux-foundation.org, mark@fasheh.com Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net Hi, On 2022/10/21 13:29, Luben Tuikov wrote: > On 2022-10-20 22:20, Yang Yingliang wrote: >> The previous discussion link: >> https://lore.kernel.org/lkml/0db486eb-6927-927e-3629-958f8f211194@huawei.com/T/ > The very first discussion on this was here: > > https://www.spinics.net/lists/dri-devel/msg368077.html > > Please use this link, and not the that one up there you which quoted above, > and whose commit description is taken verbatim from the this link. I found this leaks in bus_register()/class_register()/kset_create_and_add() at first, and describe the reason in these patches which is using kobject_set_name() description, here is the patches: https://lore.kernel.org/lkml/20221017014957.156645-1-yangyingliang@huawei.com/T/ https://lore.kernel.org/lkml/20221017031335.1845383-1-yangyingliang@huawei.com/ https://lore.kernel.org/lkml/Y0zfPKAgQSrYZg5o@kroah.com/T/ And then I found other subsystem also have this problem, so posted the fix patches for them (including qemu_fw_cfg/f2fs/erofs/ocfs2/amdgpu_discovery): https://www.mail-archive.com/qemu-devel@nongnu.org/msg915553.html https://lore.kernel.org/linux-f2fs-devel/7908686b-9a7c-b754-d312-d689fc28366e@kernel.org/T/#t https://lore.kernel.org/linux-erofs/20221018073947.693206-1-yangyingliang@huawei.com/ https://lore.kernel.org/lkml/0db486eb-6927-927e-3629-958f8f211194@huawei.com/T/ https://www.spinics.net/lists/dri-devel/msg368092.html In the amdgpu_discovery patch, I sent a old one which using wrong description and you pointer out, and then I send a v2. And then the maintainer of ocfs2 has different thought about this, so we had a discussion in the link that I gave out, and Greg suggested me to update kset_register() documentation and then put the fix patches together in one series, so I sent this patchset and use the link. Thanks, Yang > >> kset_register() is currently used in some places without calling >> kset_put() in error path, because the callers think it should be >> kset internal thing to do, but the driver core can not know what >> caller doing with that memory at times. The memory could be freed >> both in kset_put() and error path of caller, if it is called in >> kset_register(). > As I explained in the link above, the reason there's > a memory leak is that one cannot call kset_register() without > the kset->kobj.name being set--kobj_add_internal() returns -EINVAL, > in this case, i.e. kset_register() fails with -EINVAL. > > Thus, the most common usage is something like this: > > kobj_set_name(&kset->kobj, format, ...); > kset->kobj.kset = parent_kset; > kset->kobj.ktype = ktype; > res = kset_register(kset); > > So, what is being leaked, is the memory allocated in kobj_set_name(), > by the common idiom shown above. This needs to be mentioned in > the documentation, at least, in case, in the future this is absolved > in kset_register() redesign, etc. > > Regards, > Luben > >> So make the function documentation more explicit about calling >> kset_put() in the error path of caller first, so that people >> have a chance to know what to do here, then fixes this leaks >> by calling kset_put() from callers. >> >> Liu Shixin (1): >> ubifs: Fix memory leak in ubifs_sysfs_init() >> >> Yang Yingliang (10): >> kset: fix documentation for kset_register() >> kset: add null pointer check in kset_put() >> bus: fix possible memory leak in bus_register() >> kobject: fix possible memory leak in kset_create_and_add() >> class: fix possible memory leak in __class_register() >> firmware: qemu_fw_cfg: fix possible memory leak in >> fw_cfg_build_symlink() >> f2fs: fix possible memory leak in f2fs_init_sysfs() >> erofs: fix possible memory leak in erofs_init_sysfs() >> ocfs2: possible memory leak in mlog_sys_init() >> drm/amdgpu/discovery: fix possible memory leak >> >> drivers/base/bus.c | 4 +++- >> drivers/base/class.c | 6 ++++++ >> drivers/firmware/qemu_fw_cfg.c | 2 +- >> drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c | 5 +++-- >> fs/erofs/sysfs.c | 4 +++- >> fs/f2fs/sysfs.c | 4 +++- >> fs/ocfs2/cluster/masklog.c | 7 ++++++- >> fs/ubifs/sysfs.c | 2 ++ >> include/linux/kobject.h | 3 ++- >> lib/kobject.c | 5 ++++- >> 10 files changed, 33 insertions(+), 9 deletions(-) >> > . _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel