device property: Avoid potential dereferences of invalid pointers

Since fwnode may hold ERR_PTR(-ENODEV) or it may be NULL,
the fwnode type checks is_of_node(), is_acpi_node() and is
is_pset_node() need to consider it. Using IS_ERR_OR_NULL()
to check it.

Fixes: 0d67e0fa1664 (device property: fix for a case of use-after-free)
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
[ rjw: Subject & changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/base/property.c b/drivers/base/property.c
index 9b1a65d..7f692ac 100644 (file)
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -21,7 +21,7 @@
 
 static inline bool is_pset_node(struct fwnode_handle *fwnode)
 {
-       return fwnode && fwnode->type == FWNODE_PDATA;
+       return !IS_ERR_OR_NULL(fwnode) && fwnode->type == FWNODE_PDATA;
 }
 
 static inline struct property_set *to_pset_node(struct fwnode_handle *fwnode)

diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 14362a8..3a93250 100644 (file)
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -394,13 +394,13 @@ struct acpi_data_node {
 
 static inline bool is_acpi_node(struct fwnode_handle *fwnode)
 {
-       return fwnode && (fwnode->type == FWNODE_ACPI
+       return !IS_ERR_OR_NULL(fwnode) && (fwnode->type == FWNODE_ACPI
                || fwnode->type == FWNODE_ACPI_DATA);
 }
 
 static inline bool is_acpi_device_node(struct fwnode_handle *fwnode)
 {
-       return fwnode && fwnode->type == FWNODE_ACPI;
+       return !IS_ERR_OR_NULL(fwnode) && fwnode->type == FWNODE_ACPI;
 }
 
 static inline struct acpi_device *to_acpi_device_node(struct fwnode_handle *fwnode)

diff --git a/include/linux/of.h b/include/linux/of.h
index 7fcb681..3175803 100644 (file)
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -133,7 +133,7 @@ void of_core_init(void);
 
 static inline bool is_of_node(struct fwnode_handle *fwnode)
 {
-       return fwnode && fwnode->type == FWNODE_OF;
+       return !IS_ERR_OR_NULL(fwnode) && fwnode->type == FWNODE_OF;
 }
 
 static inline struct device_node *to_of_node(struct fwnode_handle *fwnode)