USB: Trival cleanup in MSM drivers

Changes:
1. strncpy() to strlcpy()
2. sprintf() to snprintf()
3. Add buffer size in sscanf()
4. Fix the accessing of NULL pointers

Change-Id: I27c05d21a6551026764b0d3b2dbd8756a5992b20
Signed-off-by: Rajkumar Raghupathy <raghup@codeaurora.org>
diff --git a/drivers/usb/gadget/android.c b/drivers/usb/gadget/android.c
index a86e049..8d58833 100644
--- a/drivers/usb/gadget/android.c
+++ b/drivers/usb/gadget/android.c
@@ -320,7 +320,7 @@
 		struct device *device, struct device_attribute *attr,
 		const char *buff, size_t size)
 {
-	strncpy(diag_clients, buff, sizeof(diag_clients));
+	strlcpy(diag_clients, buff, sizeof(diag_clients));
 
 	return size;
 }
@@ -348,7 +348,7 @@
 	int once = 0, err = -1;
 	int (*notify)(uint32_t, const char *) = NULL;
 
-	strncpy(buf, diag_clients, sizeof(buf));
+	strlcpy(buf, diag_clients, sizeof(buf));
 	b = strim(buf);
 
 	while (b) {
@@ -381,7 +381,7 @@
 		struct device *device, struct device_attribute *attr,
 		const char *buff, size_t size)
 {
-	strncpy(serial_transports, buff, sizeof(serial_transports));
+	strlcpy(serial_transports, buff, sizeof(serial_transports));
 
 	return size;
 }
@@ -407,7 +407,7 @@
 		goto bind_config;
 
 	serial_initialized = 1;
-	strncpy(buf, serial_transports, sizeof(buf));
+	strlcpy(buf, serial_transports, sizeof(buf));
 	b = strim(buf);
 
 	while (b) {
@@ -673,7 +673,7 @@
 {
 	struct android_usb_function *f = dev_get_drvdata(dev);
 	struct rndis_function_config *config = f->config;
-	return sprintf(buf, "%s\n", config->manufacturer);
+	return snprintf(buf, PAGE_SIZE, "%s\n", config->manufacturer);
 }
 
 static ssize_t rndis_manufacturer_store(struct device *dev,
@@ -684,7 +684,7 @@
 
 	if (size >= sizeof(config->manufacturer))
 		return -EINVAL;
-	if (sscanf(buf, "%s", config->manufacturer) == 1)
+	if (sscanf(buf, "%255s", config->manufacturer) == 1)
 		return size;
 	return -1;
 }
@@ -697,7 +697,7 @@
 {
 	struct android_usb_function *f = dev_get_drvdata(dev);
 	struct rndis_function_config *config = f->config;
-	return sprintf(buf, "%d\n", config->wceis);
+	return snprintf(buf, PAGE_SIZE, "%d\n", config->wceis);
 }
 
 static ssize_t rndis_wceis_store(struct device *dev,
@@ -722,7 +722,7 @@
 {
 	struct android_usb_function *f = dev_get_drvdata(dev);
 	struct rndis_function_config *rndis = f->config;
-	return sprintf(buf, "%02x:%02x:%02x:%02x:%02x:%02x\n",
+	return snprintf(buf, PAGE_SIZE, "%02x:%02x:%02x:%02x:%02x:%02x\n",
 		rndis->ethaddr[0], rndis->ethaddr[1], rndis->ethaddr[2],
 		rndis->ethaddr[3], rndis->ethaddr[4], rndis->ethaddr[5]);
 }
@@ -749,7 +749,7 @@
 {
 	struct android_usb_function *f = dev_get_drvdata(dev);
 	struct rndis_function_config *config = f->config;
-	return sprintf(buf, "%04x\n", config->vendorID);
+	return snprintf(buf, PAGE_SIZE, "%04x\n", config->vendorID);
 }
 
 static ssize_t rndis_vendorID_store(struct device *dev,
@@ -844,7 +844,7 @@
 {
 	struct android_usb_function *f = dev_get_drvdata(dev);
 	struct mass_storage_function_config *config = f->config;
-	return sprintf(buf, "%s\n", config->common->inquiry_string);
+	return snprintf(buf, PAGE_SIZE, "%s\n", config->common->inquiry_string);
 }
 
 static ssize_t mass_storage_inquiry_store(struct device *dev,
@@ -854,7 +854,7 @@
 	struct mass_storage_function_config *config = f->config;
 	if (size >= sizeof(config->common->inquiry_string))
 		return -EINVAL;
-	if (sscanf(buf, "%s", config->common->inquiry_string) != 1)
+	if (sscanf(buf, "%28s", config->common->inquiry_string) != 1)
 		return -EINVAL;
 	return size;
 }
@@ -935,7 +935,7 @@
 	struct android_usb_function *f;
 	struct device_attribute **attrs;
 	struct device_attribute *attr;
-	int err;
+	int err = 0;
 	int index = 0;
 
 	for (; (f = *functions++); index++) {
@@ -1048,7 +1048,7 @@
 	char *buff = buf;
 
 	list_for_each_entry(f, &dev->enabled_functions, enabled_list)
-		buff += sprintf(buff, "%s,", f->name);
+		buff += snprintf(buff, PAGE_SIZE, "%s,", f->name);
 	if (buff != buf)
 		*(buff-1) = '\n';
 	return buff - buf;
@@ -1065,7 +1065,7 @@
 
 	INIT_LIST_HEAD(&dev->enabled_functions);
 
-	strncpy(buf, buff, sizeof(buf));
+	strlcpy(buf, buff, sizeof(buf));
 	b = strim(buf);
 
 	while (b) {
@@ -1084,7 +1084,7 @@
 			   char *buf)
 {
 	struct android_dev *dev = dev_get_drvdata(pdev);
-	return sprintf(buf, "%d\n", dev->enabled);
+	return snprintf(buf, PAGE_SIZE, "%d\n", dev->enabled);
 }
 
 static ssize_t enable_store(struct device *pdev, struct device_attribute *attr,
@@ -1138,7 +1138,7 @@
 		state = "CONNECTED";
 	spin_unlock_irqrestore(&cdev->lock, flags);
 out:
-	return sprintf(buf, "%s\n", state);
+	return snprintf(buf, PAGE_SIZE, "%s\n", state);
 }
 
 #define DESCRIPTOR_ATTR(field, format_string)				\
@@ -1146,7 +1146,8 @@
 field ## _show(struct device *dev, struct device_attribute *attr,	\
 		char *buf)						\
 {									\
-	return sprintf(buf, format_string, device_desc.field);		\
+	return snprintf(buf, PAGE_SIZE,					\
+			format_string, device_desc.field);		\
 }									\
 static ssize_t								\
 field ## _store(struct device *dev, struct device_attribute *attr,	\
@@ -1166,14 +1167,14 @@
 field ## _show(struct device *dev, struct device_attribute *attr,	\
 		char *buf)						\
 {									\
-	return sprintf(buf, "%s", buffer);				\
+	return snprintf(buf, PAGE_SIZE, "%s", buffer);			\
 }									\
 static ssize_t								\
 field ## _store(struct device *dev, struct device_attribute *attr,	\
 		const char *buf, size_t size)		       		\
 {									\
 	if (size >= sizeof(buffer)) return -EINVAL;			\
-	if (sscanf(buf, "%s", buffer) == 1) {			       	\
+	if (sscanf(buf, "%255s", buffer) == 1) {			\
 		return size;						\
 	}								\
 	return -1;							\
@@ -1261,9 +1262,10 @@
 	device_desc.iProduct = id;
 
 	/* Default strings - should be updated by userspace */
-	strncpy(manufacturer_string, "Android", sizeof(manufacturer_string) - 1);
-	strncpy(product_string, "Android", sizeof(product_string) - 1);
-	strncpy(serial_string, "0123456789ABCDEF", sizeof(serial_string) - 1);
+	strlcpy(manufacturer_string, "Android",
+		sizeof(manufacturer_string) - 1);
+	strlcpy(product_string, "Android", sizeof(product_string) - 1);
+	strlcpy(serial_string, "0123456789ABCDEF", sizeof(serial_string) - 1);
 
 	id = usb_string_id(cdev);
 	if (id < 0)
diff --git a/drivers/usb/gadget/f_rmnet.c b/drivers/usb/gadget/f_rmnet.c
index ebbd1d8..69f158a 100644
--- a/drivers/usb/gadget/f_rmnet.c
+++ b/drivers/usb/gadget/f_rmnet.c
@@ -701,6 +701,9 @@
 
 	f->descriptors = usb_copy_descriptors(rmnet_fs_function);
 
+	if (!f->descriptors)
+		goto fail;
+
 	dev->fs.in = usb_find_endpoint(rmnet_fs_function,
 					f->descriptors,
 					&rmnet_fs_in_desc);
@@ -722,6 +725,9 @@
 		/* copy descriptors, and track endpoint copies */
 		f->hs_descriptors = usb_copy_descriptors(rmnet_hs_function);
 
+		if (!f->hs_descriptors)
+			goto fail;
+
 		dev->hs.in = usb_find_endpoint(rmnet_hs_function,
 				f->hs_descriptors, &rmnet_hs_in_desc);
 		dev->hs.out = usb_find_endpoint(rmnet_hs_function,
@@ -737,6 +743,9 @@
 
 	return 0;
 
+fail:
+	if (f->descriptors)
+		usb_free_descriptors(f->descriptors);
 ep_notify_alloc_fail:
 	dev->notify->driver_data = NULL;
 	dev->notify = NULL;