From patchwork Mon Oct 11 12:58:46 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wang Wensheng X-Patchwork-Id: 12549901 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 76E57C433F5 for ; Mon, 11 Oct 2021 13:00:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5B4F260EE9 for ; Mon, 11 Oct 2021 13:00:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236736AbhJKNCH (ORCPT ); Mon, 11 Oct 2021 09:02:07 -0400 Received: from szxga03-in.huawei.com ([45.249.212.189]:24240 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235237AbhJKNCH (ORCPT ); Mon, 11 Oct 2021 09:02:07 -0400 Received: from dggeme762-chm.china.huawei.com (unknown [172.30.72.55]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4HSf4f0N7tz8tXR; Mon, 11 Oct 2021 20:58:58 +0800 (CST) Received: from huawei.com (10.175.112.208) by dggeme762-chm.china.huawei.com (10.3.19.108) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.8; Mon, 11 Oct 2021 21:00:02 +0800 From: Wang Wensheng To: , , , , CC: Subject: [PATCH -next] iio: buffer: Check the return value of kstrdup_const() Date: Mon, 11 Oct 2021 12:58:46 +0000 Message-ID: <20211011125846.66553-1-wangwensheng4@huawei.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-Originating-IP: [10.175.112.208] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggeme762-chm.china.huawei.com (10.3.19.108) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org We should check the duplication of attr.name properly in iio_buffer_wrap_attr() or a null-pointer-dereference would occur on destroying the related sysfs file. This issue is found by fault-injection. BUG: kernel NULL pointer dereference, address: 0000000000000000 PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI RIP: 0010:strlen+0x0/0x20 Call Trace: kernfs_name_hash+0x1c/0xb0 kernfs_find_ns+0xc6/0x160 kernfs_remove_by_name_ns+0x5c/0xb0 remove_files.isra.1+0x42/0x90 internal_create_group+0x42f/0x460 internal_create_groups+0x49/0xc0 device_add+0xb5b/0xbe0 ? kobject_get+0x90/0xa0 cdev_device_add+0x2b/0x90 __iio_device_register+0xa56/0xb40 Fixes: 15097c7a1adc ("iio: buffer: wrap all buffer attributes into iio_dev_attr") Reported-by: Hulk Robot Signed-off-by: Wang Wensheng --- drivers/iio/industrialio-buffer.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c index c648e9553edd..f4011c477bac 100644 --- a/drivers/iio/industrialio-buffer.c +++ b/drivers/iio/industrialio-buffer.c @@ -1312,6 +1312,8 @@ 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) + return NULL; sysfs_attr_init(&iio_attr->dev_attr.attr); list_add(&iio_attr->l, &buffer->buffer_attr_list);