[patch] HID: roccat: potential out of bounds in pyra_sysfs_write_settings()

[patch] HID: roccat: potential out of bounds in pyra_sysfs_write_settings()

[Dan Carpenter]

This is a static checker fix.  We write some binary settings to the
sysfs file.  One of the settings is the "->startup_profile".  There
isn't any checking to make sure it fits into the
pyra->profile_settings[] array in the profile_activated() function.

I added a check to pyra_sysfs_write_settings() in both places because
I wasn't positive that the other callers were correct.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/drivers/hid/hid-roccat-pyra.c b/drivers/hid/hid-roccat-pyra.c
index 1a07e07..47d7e74 100644
--- a/drivers/hid/hid-roccat-pyra.c
+++ b/drivers/hid/hid-roccat-pyra.c
@@ -35,6 +35,8 @@ static struct class *pyra_class;
 static void profile_activated(struct pyra_device *pyra,
 		unsigned int new_profile)
 {
+	if (new_profile >= ARRAY_SIZE(pyra->profile_settings))
+		return;
 	pyra->actual_profile = new_profile;
 	pyra->actual_cpi = pyra->profile_settings[pyra->actual_profile].y_cpi;
 }
@@ -257,9 +259,11 @@ static ssize_t pyra_sysfs_write_settings(struct file *fp,
 	if (off != 0 || count != PYRA_SIZE_SETTINGS)
 		return -EINVAL;
 
-	mutex_lock(&pyra->pyra_lock);
-
 	settings = (struct pyra_settings const *)buf;
+	if (settings->startup_profile >= ARRAY_SIZE(pyra->profile_settings))
+		return -EINVAL;
+
+	mutex_lock(&pyra->pyra_lock);
 
 	retval = pyra_set_settings(usb_dev, settings);
 	if (retval) {

Re: [patch] HID: roccat: potential out of bounds in pyra_sysfs_write_settings()

[Jiri Kosina]

On Fri, 9 Jan 2015, Dan Carpenter wrote:

> This is a static checker fix.  We write some binary settings to the
> sysfs file.  One of the settings is the "->startup_profile".  There
> isn't any checking to make sure it fits into the
> pyra->profile_settings[] array in the profile_activated() function.
> 
> I added a check to pyra_sysfs_write_settings() in both places because
> I wasn't positive that the other callers were correct.
> 
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

Applied to hid.git#for-3.19/upstream-fixes. Thanks,

-- 
Jiri Kosina
SUSE Labs