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 6A3DAC28D13 for ; Thu, 25 Aug 2022 11:26:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241535AbiHYL0N (ORCPT ); Thu, 25 Aug 2022 07:26:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37580 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238494AbiHYL0M (ORCPT ); Thu, 25 Aug 2022 07:26:12 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B89D0402D5; Thu, 25 Aug 2022 04:26:10 -0700 (PDT) Received: from canpemm500010.china.huawei.com (unknown [172.30.72.53]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4MD0v00BwXzlWX4; Thu, 25 Aug 2022 19:22:52 +0800 (CST) Received: from [10.174.178.185] (10.174.178.185) by canpemm500010.china.huawei.com (7.192.105.118) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Thu, 25 Aug 2022 19:26:07 +0800 Subject: Re: [PATCH -next] scsi: be2iscsi: fix null-ptr-deref in beiscsi_alloc_mem To: , , , References: <20220727072132.3906922-1-yebin10@huawei.com> From: yebin Message-ID: <63075C4F.3010506@huawei.com> Date: Thu, 25 Aug 2022 19:26:07 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.1.0 MIME-Version: 1.0 In-Reply-To: <20220727072132.3906922-1-yebin10@huawei.com> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.178.185] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To canpemm500010.china.huawei.com (7.192.105.118) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org ping... On 2022/7/27 15:21, Ye Bin wrote: > Coccicheck report follow issue: > ./drivers/scsi/be2iscsi/be_main.c:2561:37-41: ERROR: mem_descr -> mem_array is NULL but dereferenced. > ./drivers/scsi/be2iscsi/be_main.c:2563:9-24: ERROR: mem_descr -> mem_array is NULL but dereferenced. > ./drivers/scsi/be2iscsi/be_main.c:2566:9-20: ERROR: mem_descr -> mem_array is NULL but dereferenced. > > If goto free_mem, that's mean last "mem_descr->mem_array" is NULL. However, > to avoid resource there will set "mem_descr->num_elements" with "j" which > maybe non-zero. Then will lead to null-ptr-deref when free dma resource. > > To solved above issue set "mem_descr->mem_array" with "mem_arr_orig" > when free memory. > > Signed-off-by: Ye Bin > --- > drivers/scsi/be2iscsi/be_main.c | 10 +++++++--- > 1 file changed, 7 insertions(+), 3 deletions(-) > > diff --git a/drivers/scsi/be2iscsi/be_main.c b/drivers/scsi/be2iscsi/be_main.c > index 50a577ac3bb4..08f856447b4a 100644 > --- a/drivers/scsi/be2iscsi/be_main.c > +++ b/drivers/scsi/be2iscsi/be_main.c > @@ -2540,13 +2540,13 @@ static int beiscsi_alloc_mem(struct beiscsi_hba *phba) > mem_arr++; > } > } while (alloc_size); > - mem_descr->num_elements = j; > - mem_descr->size_in_bytes = phba->mem_req[i]; > mem_descr->mem_array = kmalloc_array(j, sizeof(*mem_arr), > GFP_KERNEL); > if (!mem_descr->mem_array) > goto free_mem; > > + mem_descr->num_elements = j; > + mem_descr->size_in_bytes = phba->mem_req[i]; > memcpy(mem_descr->mem_array, mem_arr_orig, > sizeof(struct mem_array) * j); > mem_descr++; > @@ -2554,7 +2554,11 @@ static int beiscsi_alloc_mem(struct beiscsi_hba *phba) > kfree(mem_arr_orig); > return 0; > free_mem: > - mem_descr->num_elements = j; > + if (j) { > + mem_descr->num_elements = j; > + mem_descr->mem_array = mem_arr_orig; > + mem_arr_orig = NULL; > + } > while ((i) || (j)) { > for (j = mem_descr->num_elements; j > 0; j--) { > dma_free_coherent(&phba->pcidev->dev,