ieee802154: atusb: do not use the stack for buffers to make them DMA able

commit 05a974efa4bdf6e2a150e3f27dc6fcf0a9ad5655 upstream.

From 4.9 we should really avoid using the stack here as this will not be DMA
able on various platforms. This changes the buffers already being present in
time of 4.9 being released. This should go into stable as well.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/ieee802154/atusb.c b/drivers/net/ieee802154/atusb.c
index 199a94a9c8bcf83aeb78c5e694808a71227a1789..3a429f1a8002958819a29404689b4c6e17be34f3 100644 (file)
--- a/drivers/net/ieee802154/atusb.c
+++ b/drivers/net/ieee802154/atusb.c
@@ -110,13 +110,26 @@ static int atusb_read_reg(struct atusb *atusb, uint8_t reg)
 {
        struct usb_device *usb_dev = atusb->usb_dev;
        int ret;
+       uint8_t *buffer;
        uint8_t value;
 
+       buffer = kmalloc(1, GFP_KERNEL);
+       if (!buffer)
+               return -ENOMEM;
+
        dev_dbg(&usb_dev->dev, "atusb: reg = 0x%x\n", reg);
        ret = atusb_control_msg(atusb, usb_rcvctrlpipe(usb_dev, 0),
                                ATUSB_REG_READ, ATUSB_REQ_FROM_DEV,
-                               0, reg, &value, 1, 1000);
-       return ret >= 0 ? value : ret;
+                               0, reg, buffer, 1, 1000);
+
+       if (ret >= 0) {
+               value = buffer[0];
+               kfree(buffer);
+               return value;
+       } else {
+               kfree(buffer);
+               return ret;
+       }
 }
 
 static int atusb_write_subreg(struct atusb *atusb, uint8_t reg, uint8_t mask,
@@ -517,9 +530,13 @@ static struct ieee802154_ops atusb_ops = {
 static int atusb_get_and_show_revision(struct atusb *atusb)
 {
        struct usb_device *usb_dev = atusb->usb_dev;
-       unsigned char buffer[3];
+       unsigned char *buffer;
        int ret;
 
+       buffer = kmalloc(3, GFP_KERNEL);
+       if (!buffer)
+               return -ENOMEM;
+
        /* Get a couple of the ATMega Firmware values */
        ret = atusb_control_msg(atusb, usb_rcvctrlpipe(usb_dev, 0),
                                ATUSB_ID, ATUSB_REQ_FROM_DEV, 0, 0,
@@ -535,15 +552,20 @@ static int atusb_get_and_show_revision(struct atusb *atusb)
                dev_info(&usb_dev->dev, "Please update to version 0.2 or newer");
        }
 
+       kfree(buffer);
        return ret;
 }
 
 static int atusb_get_and_show_build(struct atusb *atusb)
 {
        struct usb_device *usb_dev = atusb->usb_dev;
-       char build[ATUSB_BUILD_SIZE + 1];
+       char *build;
        int ret;
 
+       build = kmalloc(ATUSB_BUILD_SIZE + 1, GFP_KERNEL);
+       if (!build)
+               return -ENOMEM;
+
        ret = atusb_control_msg(atusb, usb_rcvctrlpipe(usb_dev, 0),
                                ATUSB_BUILD, ATUSB_REQ_FROM_DEV, 0, 0,
                                build, ATUSB_BUILD_SIZE, 1000);
@@ -552,6 +574,7 @@ static int atusb_get_and_show_build(struct atusb *atusb)
                dev_info(&usb_dev->dev, "Firmware: build %s\n", build);
        }
 
+       kfree(build);
        return ret;
 }