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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 88671C433EF for ; Sun, 17 Oct 2021 13:47:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6020E60FD9 for ; Sun, 17 Oct 2021 13:47:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242471AbhJQNtt (ORCPT ); Sun, 17 Oct 2021 09:49:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:54300 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236636AbhJQNts (ORCPT ); Sun, 17 Oct 2021 09:49:48 -0400 Received: from jic23-huawei (cpc108967-cmbg20-2-0-cust86.5-4.cable.virginm.net [81.101.6.87]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B905160FD8; Sun, 17 Oct 2021 13:47:37 +0000 (UTC) Date: Sun, 17 Oct 2021 14:51:52 +0100 From: Jonathan Cameron To: Yang Yingliang Cc: , , , Subject: Re: [PATCH] iio: buffer: check return value of kstrdup_const() Message-ID: <20211017145152.4a174093@jic23-huawei> In-Reply-To: <20211013040438.1689277-1-yangyingliang@huawei.com> References: <20211013040438.1689277-1-yangyingliang@huawei.com> X-Mailer: Claws Mail 4.0.0 (GTK+ 3.24.30; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org On Wed, 13 Oct 2021 12:04:38 +0800 Yang Yingliang wrote: > Check return value of kstrdup_const() in iio_buffer_wrap_attr(), > or it will cause null-ptr-deref in kernfs_name_hash() when calling > device_add() as follows: > > BUG: kernel NULL pointer dereference, address: 0000000000000000 > RIP: 0010:strlen+0x0/0x20 > Call Trace: > kernfs_name_hash+0x22/0x110 > kernfs_find_ns+0x11d/0x390 > kernfs_remove_by_name_ns+0x3b/0xb0 > remove_files.isra.1+0x7b/0x190 > internal_create_group+0x7f1/0xbb0 > internal_create_groups+0xa3/0x150 > device_add+0x8f0/0x2020 > cdev_device_add+0xc3/0x160 > __iio_device_register+0x1427/0x1b40 [industrialio] > __devm_iio_device_register+0x22/0x80 [industrialio] > adjd_s311_probe+0x195/0x200 [adjd_s311] > i2c_device_probe+0xa07/0xbb0 > > Reported-by: Hulk Robot > Fixes: 15097c7a1adc ("iio: buffer: wrap all buffer attributes into iio_dev_attr") > Signed-off-by: Yang Yingliang Wang Wensheng sent another fix for this patch, but as that was missing the iio_attr free I have picked up this one. Applied to the fixes-togreg branch of iio.git and marked for stable. Thanks, Jonathan > --- > drivers/iio/industrialio-buffer.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c > index 5f4bd0b73d03..547a92d469ae 100644 > --- a/drivers/iio/industrialio-buffer.c > +++ b/drivers/iio/industrialio-buffer.c > @@ -1312,6 +1312,11 @@ static struct attribute *iio_buffer_wrap_attr(struct iio_buffer *buffer, > iio_attr->buffer = buffer; > memcpy(&iio_attr->dev_attr, dattr, sizeof(iio_attr->dev_attr)); > iio_attr->dev_attr.attr.name = kstrdup_const(attr->name, GFP_KERNEL); > + if (!iio_attr->dev_attr.attr.name) { > + kfree(iio_attr); > + return NULL; > + } > + > sysfs_attr_init(&iio_attr->dev_attr.attr); > > list_add(&iio_attr->l, &buffer->buffer_attr_list);