From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CD5FE1B4241; Mon, 14 Apr 2025 07:22:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.19 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744615371; cv=none; b=JcWSbqqdp1ybDNodbMHDdwEk9mhlmE08TaHMelU12TE3lV0VTMGEuDiRqSAWkAvkeHRnfWnfl03AyhQkXKJM6/t82gr3A9Kb5i41mrmhll289O/qFxhxGYFgFPAqDxH078HsAsSKRmffg2KnQlnoYh6Dv+GEbWFcIJHmVcMVnN8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744615371; c=relaxed/simple; bh=IOILmuO2B3RZBYuN+CUITTHeDhATmMItT1uR2lClnoM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=rhD7SSBwdGtW97Opk+kplgd6xv02lAtJawDp/wmFIBfGqL8tCLa7jQ+EXq/PTrIJuZ3cdoG1eHxROQqwo9lh6duIaL/4TcJvXRqlyd0XzEWcYr+If+kMcEO40help3Gxw1E8qg3jKs9q4UI1GKNjK++iaGB40sy02aSv363r2Xs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=LvObdVba; arc=none smtp.client-ip=192.198.163.19 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="LvObdVba" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1744615369; x=1776151369; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=IOILmuO2B3RZBYuN+CUITTHeDhATmMItT1uR2lClnoM=; b=LvObdVbaUSY5/wKhbiC9XfQRSJhIZFvS32jqoAbUl6WdntBW0vtCyLO0 RJyrtMRn4LEz5/smXwB6N9O0k4K8c3PKoQBQCgywR6oUVCm4jgjor9mF/ ZNTl3Pm5zuSjgaBRQLDT6Voan1s4hzANFF5c6hXR7okKpcOPVfamKDA7+ 7Y+8H4enlHE7c3MHS8SMuxAH2fwRMInXfa/PdtcZVglh1AVHXTc/EDCBc LZMB1yGG6XkcOH9xI8g/yX1UjmP6fM2T8RPOvzlBVP1+Qd9gi11Hqig6S AWfvt7HUQ68xvSL/eGAbJ4VlEY+oEghDmcAAKo8GvJ3utOn3Vk1ARtRse A==; X-CSE-ConnectionGUID: ogJLm5uORaa40SBX1KQ3yw== X-CSE-MsgGUID: 89nMMZZuRKOxJObagNUNgg== X-IronPort-AV: E=McAfee;i="6700,10204,11402"; a="45210027" X-IronPort-AV: E=Sophos;i="6.15,211,1739865600"; d="scan'208";a="45210027" Received: from fmviesa009.fm.intel.com ([10.60.135.149]) by fmvoesa113.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Apr 2025 00:22:49 -0700 X-CSE-ConnectionGUID: kFfeufNeQIKrUspjwLFnhQ== X-CSE-MsgGUID: vwvFqfg9TTaDyMS6+tOp0A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.15,211,1739865600"; d="scan'208";a="130600144" Received: from smile.fi.intel.com ([10.237.72.58]) by fmviesa009.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Apr 2025 00:22:45 -0700 Received: from andy by smile.fi.intel.com with local (Exim 4.98.2) (envelope-from ) id 1u4E9R-0000000CA9G-3Jc1; Mon, 14 Apr 2025 10:22:41 +0300 Date: Mon, 14 Apr 2025 10:22:41 +0300 From: Andy Shevchenko To: Lizhi Xu Cc: dakr@kernel.org, djrscally@gmail.com, dvyukov@google.com, gregkh@linuxfoundation.org, heikki.krogerus@linux.intel.com, jgg@nvidia.com, kevin.tian@intel.com, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, nicolinc@nvidia.com, rafael@kernel.org, sakari.ailus@linux.intel.com, syzbot+2ff22910687ee0dfd48e@syzkaller.appspotmail.com, syzkaller-bugs@googlegroups.com, yi.l.liu@intel.com Subject: Re: [PATCH V2] software node: Prevent link creation failure from causing kobj reference count imbalance Message-ID: References: <20250414071123.1228331-1-lizhi.xu@windriver.com> Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250414071123.1228331-1-lizhi.xu@windriver.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo On Mon, Apr 14, 2025 at 03:11:23PM +0800, Lizhi Xu wrote: > syzbot reported a uaf in software_node_notify_remove. [1] > > When any of the two sysfs_create_link() in software_node_notify() fails, > the swnode->kobj reference count will not increase normally, which will > cause swnode to be released incorrectly due to the imbalance of kobj reference > count when executing software_node_notify_remove(). > > Increase the reference count of kobj before creating the link to avoid uaf. > > [1] > BUG: KASAN: slab-use-after-free in software_node_notify_remove+0x1bc/0x1c0 drivers/base/swnode.c:1108 > Read of size 1 at addr ffff888033c08908 by task syz-executor105/5844 > Freed by task 5844: > software_node_notify_remove+0x159/0x1c0 drivers/base/swnode.c:1106 > device_platform_notify_remove drivers/base/core.c:2387 [inline] The fix looks correct to me, Reviewed-by: Andy Shevchenko -- With Best Regards, Andy Shevchenko