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HID: corsair: fix DMA to stack and info leaks

PATCH In review Johan Hovold 2 participants 4 messages Jan 12, 2017 – Jan 13, 2017

Subsystems (2)
Stable branch HID
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Johan Hovold

author
#0 lore raw

cover HID: corsair: fix DMA to stack and info leaks

These patches fix DMA buffers on stack and information leaks in the corsair HID driver.

Note that this series has only been compile tested.

Johan

Johan Hovold (2):
HID: corsair: fix DMA buffers on stack
HID: corsair: fix control-transfer error handling

 drivers/hid/hid-corsair.c | 60 +++++++++++++++++++++++++++++++++++------------
 1 file changed, 45 insertions(+), 15 deletions(-)
Signature · 6 lines
2.10.2

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author
#1 lore raw

PATCH 1/2 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 <[email protected]>
Signed-off-by Johan Hovold <[email protected]>
---
 drivers/hid/hid-corsair.c | 54 ++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 42 insertions(+), 12 deletions(-)
drivers/hid/hid-corsair.c +42 -12
index 717704e9ae07..5971907a23b1 100644
@@ -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,
Signature · 1 line
2.10.2
author
#2 lore raw

PATCH 2/2 HID: corsair: fix control-transfer error handling

In reply to Johan Hovold

Make sure to check for short control transfers in order to avoid parsing uninitialised buffer data and leaking it to user space.

Note that the backlight and macro-mode buffer constraints are kept as loose as possible in order to avoid any regressions should the current buffer sizes be larger than necessary.

Fixes 6f78193ee9ea ("HID: corsair: Add Corsair Vengeance K90 driver")
Cc stable <[email protected]>
Signed-off-by Johan Hovold <[email protected]>
---
 drivers/hid/hid-corsair.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
drivers/hid/hid-corsair.c +3 -3
index 5971907a23b1..c0303f61c26a 100644
@@ -159,7 +159,7 @@ static enum led_brightness k90_backlight_get(struct led_classdev *led_cdev)
 			      USB_DIR_IN | USB_TYPE_VENDOR |
 			      USB_RECIP_DEVICE, 0, 0, data, 8,
 			      USB_CTRL_SET_TIMEOUT);
-	if (ret < 0) {
+	if (ret < 5) {
 		dev_warn(dev, "Failed to get K90 initial state (error %d).\n",
 			 ret);
 		ret = -EIO;

@@ -274,7 +274,7 @@ static ssize_t k90_show_macro_mode(struct device *dev,
 			      USB_DIR_IN | USB_TYPE_VENDOR |
 			      USB_RECIP_DEVICE, 0, 0, data, 2,
 			      USB_CTRL_SET_TIMEOUT);
-	if (ret < 0) {
+	if (ret < 1) {
 		dev_warn(dev, "Failed to get K90 initial mode (error %d).\n",
 			 ret);
 		ret = -EIO;

@@ -351,7 +351,7 @@ static ssize_t k90_show_current_profile(struct device *dev,
 			      USB_DIR_IN | USB_TYPE_VENDOR |
 			      USB_RECIP_DEVICE, 0, 0, data, 8,
 			      USB_CTRL_SET_TIMEOUT);
-	if (ret < 0) {
+	if (ret < 8) {
 		dev_warn(dev, "Failed to get K90 initial state (error %d).\n",
 			 ret);
 		ret = -EIO;
Signature · 1 line
2.10.2
maintainer
#3 lore raw
In reply to Johan Hovold
Quoted 4 lines · Johan Hovold

These patches fix DMA buffers on stack and information leaks in the corsair HID driver.

Note that this series has only been compile tested.

Adding Clément to CC, and applying to for-4.10/upstream-fixes branch.

Thanks!

Signature · 2 lines
Jiri Kosina
SUSE Labs