[PATCH] extcon: Add exception handling to prevent the NULL pointer access

[Chanwoo Choi]

This patch check whether argument is NULL to prevent NULL pointer access.

Signed-off-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
---
 drivers/extcon/extcon.c | 32 +++++++++++++++++++++++++++++++-
 1 file changed, 31 insertions(+), 1 deletion(-)

diff --git a/drivers/extcon/extcon.c b/drivers/extcon/extcon.c
index 6f03ccf..dda1e62 100644
--- a/drivers/extcon/extcon.c
+++ b/drivers/extcon/extcon.c
@@ -252,6 +252,9 @@ int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
 	unsigned long flags;
 	bool attached;
 
+	if (!edev)
+		return -EINVAL;
+
 	spin_lock_irqsave(&edev->lock, flags);
 
 	if (edev->state != ((edev->state & ~mask) | (state & mask))) {
@@ -320,6 +323,9 @@ EXPORT_SYMBOL_GPL(extcon_update_state);
  */
 int extcon_set_state(struct extcon_dev *edev, u32 state)
 {
+	if (!edev)
+		return -EINVAL;
+
 	return extcon_update_state(edev, 0xffffffff, state);
 }
 EXPORT_SYMBOL_GPL(extcon_set_state);
@@ -333,6 +339,9 @@ int extcon_get_cable_state_(struct extcon_dev *edev, const unsigned int id)
 {
 	int index;
 
+	if (!edev)
+		return -EINVAL;
+
 	index = find_cable_index_by_id(edev, id);
 	if (index < 0)
 		return index;
@@ -372,6 +381,9 @@ int extcon_set_cable_state_(struct extcon_dev *edev, unsigned int id,
 	u32 state;
 	int index;
 
+	if (!edev)
+		return -EINVAL;
+
 	index = find_cable_index_by_id(edev, id);
 	if (index < 0)
 		return index;
@@ -409,6 +421,9 @@ struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
 {
 	struct extcon_dev *sd;
 
+	if (!extcon_name)
+		return ERR_PTR(-EINVAL);
+
 	mutex_lock(&extcon_dev_list_lock);
 	list_for_each_entry(sd, &extcon_dev_list, entry) {
 		if (!strcmp(sd->name, extcon_name))
@@ -537,6 +552,9 @@ int extcon_register_notifier(struct extcon_dev *edev, unsigned int id,
 	unsigned long flags;
 	int ret, idx;
 
+	if (!edev || !nb)
+		return -EINVAL;
+
 	idx = find_cable_index_by_id(edev, id);
 
 	spin_lock_irqsave(&edev->lock, flags);
@@ -559,6 +577,9 @@ int extcon_unregister_notifier(struct extcon_dev *edev, unsigned int id,
 	unsigned long flags;
 	int ret, idx;
 
+	if (!edev || !nb)
+		return -EINVAL;
+
 	idx = find_cable_index_by_id(edev, id);
 
 	spin_lock_irqsave(&edev->lock, flags);
@@ -619,6 +640,9 @@ struct extcon_dev *extcon_dev_allocate(const unsigned int *supported_cable)
 {
 	struct extcon_dev *edev;
 
+	if (!supported_cable)
+		return ERR_PTR(-EINVAL);
+
 	edev = kzalloc(sizeof(*edev), GFP_KERNEL);
 	if (!edev)
 		return ERR_PTR(-ENOMEM);
@@ -719,7 +743,7 @@ int extcon_dev_register(struct extcon_dev *edev)
 			return ret;
 	}
 
-	if (!edev->supported_cable)
+	if (!edev || !edev->supported_cable)
 		return -EINVAL;
 
 	for (; edev->supported_cable[index] != EXTCON_NONE; index++);
@@ -925,6 +949,9 @@ void extcon_dev_unregister(struct extcon_dev *edev)
 {
 	int index;
 
+	if (!edev)
+		return;
+
 	mutex_lock(&extcon_dev_list_lock);
 	list_del(&edev->entry);
 	mutex_unlock(&extcon_dev_list_lock);
@@ -1031,6 +1058,9 @@ struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
 	struct device_node *node;
 	struct extcon_dev *edev;
 
+	if (!dev)
+		return ERR_PTR(-EINVAL);
+
 	if (!dev->of_node) {
 		dev_err(dev, "device does not have a device node entry\n");
 		return ERR_PTR(-EINVAL);
-- 
2.2.0.GIT

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