[linux-yocto] [PATCH 8/8] device property: Avoid potential dereferences of invalid pointers

[wan.ahmad.zainie.wan.mohamad at intel.com]

From: Heikki Krogerus <heikki.krogerus at linux.intel.com>

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 at oracle.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus at linux.intel.com>
[ rjw: Subject & changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki at intel.com>

(cherry picked from commit 0224a4a30b57385a60065aa598181868881d8fc6)
Signed-off-by: Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad at intel.com>
---
 drivers/base/property.c | 2 +-
 include/acpi/acpi_bus.h | 4 ++--
 include/linux/of.h      | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/base/property.c b/drivers/base/property.c
index e33dad9..781ef82 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -18,7 +18,7 @@
 
 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 4796899..03ceba3 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -427,13 +427,13 @@ static inline bool acpi_check_dma(struct acpi_device *adev, bool *coherent)
 
 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 7894f9e..a437329 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -125,7 +125,7 @@ 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)
-- 
1.9.1