From patchwork Thu Jul 9 13:52:17 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Colin King X-Patchwork-Id: 11654403 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9D56A6C1 for ; Thu, 9 Jul 2020 13:52:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 89FB620708 for ; Thu, 9 Jul 2020 13:52:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727966AbgGINwZ (ORCPT ); Thu, 9 Jul 2020 09:52:25 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:36941 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726358AbgGINwX (ORCPT ); Thu, 9 Jul 2020 09:52:23 -0400 Received: from 1.general.cking.uk.vpn ([10.172.193.212] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1jtWyH-0005oE-Gq; Thu, 09 Jul 2020 13:52:17 +0000 From: Colin King To: "James E . J . Bottomley" , "Martin K . Petersen" , Varun Prakash , linux-scsi@vger.kernel.org Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH][next] scsi: cxgb4i: fix dereference of pointer tdata before it is null checked Date: Thu, 9 Jul 2020 14:52:17 +0100 Message-Id: <20200709135217.1408105-1-colin.king@canonical.com> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org From: Colin Ian King Currently pointer tdata is being dereferenced on the initialization of pointer skb before tdata is null checked. This could lead to a potential null pointer dereference. Fix this by dereferencing tdata after tdata has been null pointer sanity checked. Addresses-Coverity: ("Dereference before null check") Fixes: e33c2482289b ("scsi: cxgb4i: Add support for iSCSI segmentation offload") Signed-off-by: Colin Ian King Acked-by: Varun Prakash --- drivers/scsi/cxgbi/libcxgbi.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/cxgbi/libcxgbi.c b/drivers/scsi/cxgbi/libcxgbi.c index 1fb101c616b7..a6119d9daedf 100644 --- a/drivers/scsi/cxgbi/libcxgbi.c +++ b/drivers/scsi/cxgbi/libcxgbi.c @@ -2147,7 +2147,7 @@ int cxgbi_conn_init_pdu(struct iscsi_task *task, unsigned int offset, struct iscsi_conn *conn = task->conn; struct iscsi_tcp_task *tcp_task = task->dd_data; struct cxgbi_task_data *tdata = iscsi_task_cxgbi_data(task); - struct sk_buff *skb = tdata->skb; + struct sk_buff *skb; struct scsi_cmnd *sc = task->sc; u32 expected_count, expected_offset; u32 datalen = count, dlimit = 0; @@ -2161,6 +2161,7 @@ int cxgbi_conn_init_pdu(struct iscsi_task *task, unsigned int offset, tcp_task ? tcp_task->dd_data : NULL, tdata); return -EINVAL; } + skb = tdata->skb; log_debug(1 << CXGBI_DBG_ISCSI | 1 << CXGBI_DBG_PDU_TX, "task 0x%p,0x%p, skb 0x%p, 0x%x,0x%x,0x%x, %u+%u.\n", @@ -2365,7 +2366,7 @@ int cxgbi_conn_xmit_pdu(struct iscsi_task *task) struct iscsi_tcp_task *tcp_task = task->dd_data; struct cxgbi_task_data *tdata = iscsi_task_cxgbi_data(task); struct cxgbi_task_tag_info *ttinfo = &tdata->ttinfo; - struct sk_buff *skb = tdata->skb; + struct sk_buff *skb; struct cxgbi_sock *csk = NULL; u32 pdulen = 0; u32 datalen; @@ -2378,6 +2379,7 @@ int cxgbi_conn_xmit_pdu(struct iscsi_task *task) return -EINVAL; } + skb = tdata->skb; if (!skb) { log_debug(1 << CXGBI_DBG_ISCSI | 1 << CXGBI_DBG_PDU_TX, "task 0x%p, skb NULL.\n", task);