HID: corsair: fix DMA buffers on stack

Not all platforms support DMA to the stack, and specifically since v4.9
this is no longer supported on x86 with VMAP_STACK either.

Note that the macro-mode buffer was larger than necessary.

Fixes: 6f78193ee9ea ("HID: corsair: Add Corsair Vengeance K90 driver")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

diff --git a/drivers/hid/hid-corsair.c b/drivers/hid/hid-corsair.c
index 717704e9ae07bd97d64f38321d2d49f07de62b83..5971907a23b13db1250264f8a26c214e3c9b748a 100644 (file)
--- a/drivers/hid/hid-corsair.c
+++ b/drivers/hid/hid-corsair.c
@@ -148,7 +148,11 @@ static enum led_brightness k90_backlight_get(struct led_classdev *led_cdev)
        struct usb_interface *usbif = to_usb_interface(dev->parent);
        struct usb_device *usbdev = interface_to_usbdev(usbif);
        int brightness;
-       char data[8];
+       char *data;
+
+       data = kmalloc(8, GFP_KERNEL);
+       if (!data)
+               return -ENOMEM;
 
        ret = usb_control_msg(usbdev, usb_rcvctrlpipe(usbdev, 0),
                              K90_REQUEST_STATUS,
@@ -158,16 +162,22 @@ static enum led_brightness k90_backlight_get(struct led_classdev *led_cdev)
        if (ret < 0) {
                dev_warn(dev, "Failed to get K90 initial state (error %d).\n",
                         ret);
-               return -EIO;
+               ret = -EIO;
+               goto out;
        }
        brightness = data[4];
        if (brightness < 0 || brightness > 3) {
                dev_warn(dev,
                         "Read invalid backlight brightness: %02hhx.\n",
                         data[4]);
-               return -EIO;
+               ret = -EIO;
+               goto out;
        }
-       return brightness;
+       ret = brightness;
+out:
+       kfree(data);
+
+       return ret;
 }
 
 static enum led_brightness k90_record_led_get(struct led_classdev *led_cdev)
@@ -253,7 +263,11 @@ static ssize_t k90_show_macro_mode(struct device *dev,
        struct usb_interface *usbif = to_usb_interface(dev->parent);
        struct usb_device *usbdev = interface_to_usbdev(usbif);
        const char *macro_mode;
-       char data[8];
+       char *data;
+
+       data = kmalloc(2, GFP_KERNEL);
+       if (!data)
+               return -ENOMEM;
 
        ret = usb_control_msg(usbdev, usb_rcvctrlpipe(usbdev, 0),
                              K90_REQUEST_GET_MODE,
@@ -263,7 +277,8 @@ static ssize_t k90_show_macro_mode(struct device *dev,
        if (ret < 0) {
                dev_warn(dev, "Failed to get K90 initial mode (error %d).\n",
                         ret);
-               return -EIO;
+               ret = -EIO;
+               goto out;
        }
 
        switch (data[0]) {
@@ -277,10 +292,15 @@ static ssize_t k90_show_macro_mode(struct device *dev,
        default:
                dev_warn(dev, "K90 in unknown mode: %02hhx.\n",
                         data[0]);
-               return -EIO;
+               ret = -EIO;
+               goto out;
        }
 
-       return snprintf(buf, PAGE_SIZE, "%s\n", macro_mode);
+       ret = snprintf(buf, PAGE_SIZE, "%s\n", macro_mode);
+out:
+       kfree(data);
+
+       return ret;
 }
 
 static ssize_t k90_store_macro_mode(struct device *dev,
@@ -320,7 +340,11 @@ static ssize_t k90_show_current_profile(struct device *dev,
        struct usb_interface *usbif = to_usb_interface(dev->parent);
        struct usb_device *usbdev = interface_to_usbdev(usbif);
        int current_profile;
-       char data[8];
+       char *data;
+
+       data = kmalloc(8, GFP_KERNEL);
+       if (!data)
+               return -ENOMEM;
 
        ret = usb_control_msg(usbdev, usb_rcvctrlpipe(usbdev, 0),
                              K90_REQUEST_STATUS,
@@ -330,16 +354,22 @@ static ssize_t k90_show_current_profile(struct device *dev,
        if (ret < 0) {
                dev_warn(dev, "Failed to get K90 initial state (error %d).\n",
                         ret);
-               return -EIO;
+               ret = -EIO;
+               goto out;
        }
        current_profile = data[7];
        if (current_profile < 1 || current_profile > 3) {
                dev_warn(dev, "Read invalid current profile: %02hhx.\n",
                         data[7]);
-               return -EIO;
+               ret = -EIO;
+               goto out;
        }
 
-       return snprintf(buf, PAGE_SIZE, "%d\n", current_profile);
+       ret = snprintf(buf, PAGE_SIZE, "%d\n", current_profile);
+out:
+       kfree(data);
+
+       return ret;
 }
 
 static ssize_t k90_store_current_profile(struct device *dev,