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 16DACC678D8 for ; Mon, 9 Jan 2023 10:41:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237090AbjAIKlj (ORCPT ); Mon, 9 Jan 2023 05:41:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52102 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237084AbjAIKk6 (ORCPT ); Mon, 9 Jan 2023 05:40:58 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6D1DA186B9 for ; Mon, 9 Jan 2023 02:33:22 -0800 (PST) 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 1179160FD2 for ; Mon, 9 Jan 2023 10:33:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CA15AC433EF; Mon, 9 Jan 2023 10:33:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1673260401; bh=ZUImioBdrk3XKJsixsqfdOKeV/GUBIF4fNM0CYvWFR8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ybbsx1md5/zhL+OBdguHE/hSq9xkxsIUV68LQPrt04qspADxNXhB4ckBbpdU5v8Ou ZNaT2UTxEaPU9B5bcQYfnX9wLmhfH5jaMAlYQEib+mjXxERtVu1Cxx0MjRAfphlgZx Za+hF+fLZc7FfqT8ECTQ7LP+9o7sMT+ib96A05Xg= Date: Mon, 9 Jan 2023 11:33:17 +0100 From: Greg KH To: Wang Hai Cc: intel-wired-lan@lists.osuosl.org, linux-kernel@vger.kernel.org, anthony.l.nguyen@intel.com, rafael@kernel.org, jesse.brandeburg@intel.com, alice.chao@mediatek.com Subject: Re: [PATCH v2] kobject: Fix slab-out-of-bounds in fill_kobj_path() Message-ID: References: <20221220012143.52141-1-wanghai38@huawei.com> <54066d0e-ef50-183f-74fe-551bb99741eb@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <54066d0e-ef50-183f-74fe-551bb99741eb@huawei.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 09, 2023 at 05:37:23PM +0800, Wang Hai wrote: > > 在 2022/12/20 9:21, Wang Hai 写道: > > In kobject_get_path(), if kobj->name is changed between calls > > get_kobj_path_length() and fill_kobj_path() and the length becomes > > longer, then fill_kobj_path() will have an out-of-bounds bug. > > > > The actual current problem occurs when the ixgbe probe. > > > > In ixgbe_mii_bus_init(), if the length of netdev->dev.kobj.name > > length becomes longer, out-of-bounds will occur. > > > > cpu0 cpu1 > > ixgbe_probe > > register_netdev(netdev) > > netdev_register_kobject > > device_add > > kobject_uevent // Sending ADD events > > systemd-udevd // rename netdev > > dev_change_name > > device_rename > > kobject_rename > > ixgbe_mii_bus_init | > > mdiobus_register | > > __mdiobus_register | > > device_register | > > device_add | > > kobject_uevent | > > kobject_get_path | > > len = get_kobj_path_length // old name | > > path = kzalloc(len, gfp_mask); | > > kobj->name = name; > > /* name length becomes > > * longer > > */ > > fill_kobj_path /* kobj path length is > > * longer than path, > > * resulting in out of > > * bounds when filling path > > */ > > > > This is the kasan report: > > > > ================================================================== > > BUG: KASAN: slab-out-of-bounds in fill_kobj_path+0x50/0xc0 > > Write of size 7 at addr ff1100090573d1fd by task kworker/28:1/673 > > > > Workqueue: events work_for_cpu_fn > > Call Trace: > > > > dump_stack_lvl+0x34/0x48 > > print_address_description.constprop.0+0x86/0x1e7 > > print_report+0x36/0x4f > > kasan_report+0xad/0x130 > > kasan_check_range+0x35/0x1c0 > > memcpy+0x39/0x60 > > fill_kobj_path+0x50/0xc0 > > kobject_get_path+0x5a/0xc0 > > kobject_uevent_env+0x140/0x460 > > device_add+0x5c7/0x910 > > __mdiobus_register+0x14e/0x490 > > ixgbe_probe.cold+0x441/0x574 [ixgbe] > > local_pci_probe+0x78/0xc0 > > work_for_cpu_fn+0x26/0x40 > > process_one_work+0x3b6/0x6a0 > > worker_thread+0x368/0x520 > > kthread+0x165/0x1a0 > > ret_from_fork+0x1f/0x30 > > > > This reproducer triggers that bug: > > > > while: > > do > > rmmod ixgbe > > sleep 0.5 > > modprobe ixgbe > > sleep 0.5 > > > > When calling fill_kobj_path() to fill path, if the name length of > > kobj becomes longer, return failure and retry. This fixes the problem. > > > > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") > > Signed-off-by: Wang Hai > > --- > Hi, greg k-h. > Sorry to bother you. Can this patch be merged into the mainline? It's in my "to review" queue that I am working on. As this is not anything that a normal user can trigger, it's not that high of a priority, right? thanks, greg k-h