[PATCH 4.19 25/31] misc: rtsx_usb: use separate command and response buffers

[Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>]

From: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>

commit 3776c78559853fd151be7c41e369fd076fb679d5 upstream.

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@xxxxxxxxxxxxxxxxxxx>
Cc: stable <stable@xxxxxxxxxx>
Link: https://lore.kernel.org/r/07e3721804ff07aaab9ef5b39a5691d0718b9ade.1656642167.git.skhan@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/misc/cardreader/rtsx_usb.c |   26 +++++++++++++++++---------
 include/linux/rtsx_usb.h           |    1 -
 2 files changed, 17 insertions(+), 10 deletions(-)

--- a/drivers/misc/cardreader/rtsx_usb.c
+++ b/drivers/misc/cardreader/rtsx_usb.c
@@ -642,15 +642,18 @@ static int rtsx_usb_probe(struct usb_int
 
 	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);
 
@@ -678,9 +681,11 @@ static int rtsx_usb_probe(struct usb_int
 
 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;
 }
 
@@ -693,9 +698,12 @@ static void rtsx_usb_disconnect(struct u
 	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
--- a/include/linux/rtsx_usb.h
+++ b/include/linux/rtsx_usb.h
@@ -65,7 +65,6 @@ 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;