can: gs_usb: Don't use stack memory for USB transfers

Fixes: 05ca5270005c can: gs_usb: add ethtool set_phys_id callback to locate physical device

The gs_usb driver is performing USB transfers using buffers allocated on
the stack. This causes the driver to not function with vmapped stacks.
Instead, allocate memory for the transfer buffers.

Signed-off-by: Ethan Zonca <e@ethanzonca.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v4.8
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

1 files changed, 29 insertions, 11 deletions

diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c
index 77e3cc06a30c..a0dabd4038ba 100644
--- a/drivers/net/can/usb/gs_usb.c
+++ b/drivers/net/can/usb/gs_usb.c
@@ -908,10 +908,14 @@ static int gs_usb_probe(struct usb_interface *intf,
         struct gs_usb *dev;
         int rc = -ENOMEM;
         unsigned int icount, i;
-        struct gs_host_config hconf = {
-                .byte_order = 0x0000beef,
-        };
-        struct gs_device_config dconf;
+        struct gs_host_config *hconf;
+        struct gs_device_config *dconf;
+
+        hconf = kmalloc(sizeof(*hconf), GFP_KERNEL);
+        if (!hconf)
+                return -ENOMEM;
+
+        hconf->byte_order = 0x0000beef;
 
         /* send host config */
         rc = usb_control_msg(interface_to_usbdev(intf),
@@ -920,16 +924,22 @@ static int gs_usb_probe(struct usb_interface *intf,
                              USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
                              1,
                              intf->altsetting[0].desc.bInterfaceNumber,
-                             &hconf,
-                             sizeof(hconf),
+                             hconf,
+                             sizeof(*hconf),
                              1000);
 
+        kfree(hconf);
+
         if (rc < 0) {
                 dev_err(&intf->dev, "Couldn't send data format (err=%d)\n",
                         rc);
                 return rc;
         }
 
+        dconf = kmalloc(sizeof(*dconf), GFP_KERNEL);
+        if (!dconf)
+                return -ENOMEM;
+
         /* read device config */
         rc = usb_control_msg(interface_to_usbdev(intf),
                              usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
@@ -937,28 +947,33 @@ static int gs_usb_probe(struct usb_interface *intf,
                              USB_DIR_IN|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
                              1,
                              intf->altsetting[0].desc.bInterfaceNumber,
-                             &dconf,
-                             sizeof(dconf),
+                             dconf,
+                             sizeof(*dconf),
                              1000);
         if (rc < 0) {
                 dev_err(&intf->dev, "Couldn't get device config: (err=%d)\n",
                         rc);
+                kfree(dconf);
                 return rc;
         }
 
-        icount = dconf.icount + 1;
+        icount = dconf->icount + 1;
         dev_info(&intf->dev, "Configuring for %d interfaces\n", icount);
 
         if (icount > GS_MAX_INTF) {
                 dev_err(&intf->dev,
                         "Driver cannot handle more that %d CAN interfaces\n",
                         GS_MAX_INTF);
+                kfree(dconf);
                 return -EINVAL;
         }
 
         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
-        if (!dev)
+        if (!dev) {
+                kfree(dconf);
                 return -ENOMEM;
+        }
+
         init_usb_anchor(&dev->rx_submitted);
 
         atomic_set(&dev->active_channels, 0);
@@ -967,7 +982,7 @@ static int gs_usb_probe(struct usb_interface *intf,
         dev->udev = interface_to_usbdev(intf);
 
         for (i = 0; i < icount; i++) {
-                dev->canch[i] = gs_make_candev(i, intf, &dconf);
+                dev->canch[i] = gs_make_candev(i, intf, dconf);
                 if (IS_ERR_OR_NULL(dev->canch[i])) {
                         /* save error code to return later */
                         rc = PTR_ERR(dev->canch[i]);
@@ -978,12 +993,15 @@ static int gs_usb_probe(struct usb_interface *intf,
                                 gs_destroy_candev(dev->canch[i]);
 
                         usb_kill_anchored_urbs(&dev->rx_submitted);
+                        kfree(dconf);
                         kfree(dev);
                         return rc;
                 }
                 dev->canch[i]->parent = dev;
         }
 
+        kfree(dconf);
+
         return 0;
 }