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From:   Shuah Khan <skhan@linuxfoundation.org>
To:     arnd@arndb.de, gregkh@linuxfoundation.org
Cc:     Shuah Khan <skhan@linuxfoundation.org>,
        linux-kernel@vger.kernel.org
Subject: [PATCH 2/2] misc: rtsx_usb: use separate command and response buffers
Date:   Thu, 30 Jun 2022 20:32:56 -0600
Message-Id: <07e3721804ff07aaab9ef5b39a5691d0718b9ade.1656642167.git.skhan@linuxfoundation.org>
In-Reply-To: <cover.1656642167.git.skhan@linuxfoundation.org>
References: <cover.1656642167.git.skhan@linuxfoundation.org>
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rtsx_usb uses same buffer for command and response. There could
be a potential conflict using the same buffer for both especially
if retries and timeouts are involved.

Use separate command and response buffers to avoid conflicts.

Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
---
 drivers/misc/cardreader/rtsx_usb.c | 26 +++++++++++++++++---------
 include/linux/rtsx_usb.h           |  1 -
 2 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/drivers/misc/cardreader/rtsx_usb.c b/drivers/misc/cardreader/rtsx_usb.c
index e147cc8ab0fd..4e2108052509 100644
--- a/drivers/misc/cardreader/rtsx_usb.c
+++ b/drivers/misc/cardreader/rtsx_usb.c
@@ -631,15 +631,18 @@ static int rtsx_usb_probe(struct usb_interface *intf,
 
 	ucr->pusb_dev = usb_dev;
 
-	ucr->iobuf = kmalloc(IOBUF_SIZE, GFP_KERNEL);
-	if (!ucr->iobuf)
+	ucr->cmd_buf = kmalloc(IOBUF_SIZE, GFP_KERNEL);
+	if (!ucr->cmd_buf)
 		return -ENOMEM;
 
+	ucr->rsp_buf = kmalloc(IOBUF_SIZE, GFP_KERNEL);
+	if (!ucr->rsp_buf)
+		goto out_free_cmd_buf;
+
 	usb_set_intfdata(intf, ucr);
 
 	ucr->vendor_id = id->idVendor;
 	ucr->product_id = id->idProduct;
-	ucr->cmd_buf = ucr->rsp_buf = ucr->iobuf;
 
 	mutex_init(&ucr->dev_mutex);
 
@@ -667,9 +670,11 @@ static int rtsx_usb_probe(struct usb_interface *intf,
 
 out_init_fail:
 	usb_set_intfdata(ucr->pusb_intf, NULL);
-	kfree(ucr->iobuf);
-	ucr->iobuf = NULL;
-	ucr->cmd_buf = ucr->rsp_buf = NULL;
+	kfree(ucr->rsp_buf);
+	ucr->rsp_buf = NULL;
+out_free_cmd_buf:
+	kfree(ucr->cmd_buf);
+	ucr->cmd_buf = NULL;
 	return ret;
 }
 
@@ -682,9 +687,12 @@ static void rtsx_usb_disconnect(struct usb_interface *intf)
 	mfd_remove_devices(&intf->dev);
 
 	usb_set_intfdata(ucr->pusb_intf, NULL);
-	kfree(ucr->iobuf);
-	ucr->iobuf = NULL;
-	ucr->cmd_buf = ucr->rsp_buf = NULL;
+
+	kfree(ucr->cmd_buf);
+	ucr->cmd_buf = NULL;
+
+	kfree(ucr->rsp_buf);
+	ucr->rsp_buf = NULL;
 }
 
 #ifdef CONFIG_PM
diff --git a/include/linux/rtsx_usb.h b/include/linux/rtsx_usb.h
index a07f7341ebc2..3247ed8e9ff0 100644
--- a/include/linux/rtsx_usb.h
+++ b/include/linux/rtsx_usb.h
@@ -54,7 +54,6 @@ struct rtsx_ucr {
 	struct usb_device	*pusb_dev;
 	struct usb_interface	*pusb_intf;
 	struct usb_sg_request	current_sg;
-	unsigned char		*iobuf;
 
 	struct timer_list	sg_timer;
 	struct mutex		dev_mutex;
-- 
2.34.1