[PATCH 5.15 217/230] misc: rtsx_usb: use separate command and response buffers

Greg Kroah-Hartman
2022-07-11T10:06:03Z

From: Shuah Khan <skhan@linuxfoundation.org>

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@linuxfoundation.org>
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/07e3721804ff07aaab9ef5b39a5691d0718b9ade.1656642167.git.skhan@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
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
@@ -631,15 +631,18 @@ 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);

@@ -667,9 +670,11 @@ 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;
}

@@ -682,9 +687,12 @@ 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
@@ -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;