Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Colin King <colin.king@canonical.com>
To:     Alison Schofield <alison.schofield@intel.com>,
        Vishal Verma <vishal.l.verma@intel.com>,
        Ira Weiny <ira.weiny@intel.com>,
        Ben Widawsky <ben.widawsky@intel.com>,
        Dan Williams <dan.j.williams@intel.com>,
        Jonathan Cameron <Jonathan.Cameron@huawei.com>,
        linux-cxl@vger.kernel.org
Cc:     kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH][next] cxl/core: Fix a deference of a pointer cxl_port before it is null checked
Date:   Sun, 29 Aug 2021 18:15:53 +0100
Message-Id: <20210829171553.532596-1-colin.king@canonical.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Colin Ian King <colin.king@canonical.com>

The assignment of pointer port with a dereference of pointer cxl_port
occurs before cxl_port is null checked. Fix this by only assigning port
once cxl_port has been null checked.

Addresses-Coverity: ("Dereference before null check")
Fixes: b7ca54b62551 ("cxl/core: Split decoder setup into alloc + add")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/cxl/core/bus.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/cxl/core/bus.c b/drivers/cxl/core/bus.c
index 0b85351be6bf..55db46ba8a18 100644
--- a/drivers/cxl/core/bus.c
+++ b/drivers/cxl/core/bus.c
@@ -494,7 +494,7 @@ EXPORT_SYMBOL_GPL(cxl_decoder_alloc);
 int devm_cxl_add_decoder(struct device *host, struct cxl_decoder *cxld,
 			 int *target_map)
 {
-	struct cxl_port *port = to_cxl_port(cxld->dev.parent);
+	struct cxl_port *port;
 	struct device *dev;
 	int rc = 0, i;
 
@@ -509,6 +509,7 @@ int devm_cxl_add_decoder(struct device *host, struct cxl_decoder *cxld,
 		goto err;
 	}
 
+	port = to_cxl_port(cxld->dev.parent);
 	device_lock(&port->dev);
 	if (list_empty(&port->dports))
 		rc = -EINVAL;
-- 
2.32.0