Merge branch 'devicetree/merge' of git://git.kernel.org/pub/scm/linux/kernel/git/glikely/linux

Pull devicetree bugfix from Grant Likely:
 "One buffer overflow bug that shouldn't be left around"

* 'devicetree/merge' of git://git.kernel.org/pub/scm/linux/kernel/git/glikely/linux:
  of: Fix overflow bug in string property parsing functions

1 files changed, 70 insertions, 14 deletions

diff --git a/include/linux/of.h b/include/linux/of.h
index 6545e7aec7bb..29f0adc5f3e4 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -267,14 +267,12 @@ extern int of_property_read_u64(const struct device_node *np,
 extern int of_property_read_string(struct device_node *np,
                                    const char *propname,
                                    const char **out_string);
-extern int of_property_read_string_index(struct device_node *np,
-                                         const char *propname,
-                                         int index, const char **output);
 extern int of_property_match_string(struct device_node *np,
                                     const char *propname,
                                     const char *string);
-extern int of_property_count_strings(struct device_node *np,
-                                     const char *propname);
+extern int of_property_read_string_helper(struct device_node *np,
+                                              const char *propname,
+                                              const char **out_strs, size_t sz, int index);
 extern int of_device_is_compatible(const struct device_node *device,
                                    const char *);
 extern int of_device_is_available(const struct device_node *device);
@@ -486,15 +484,9 @@ static inline int of_property_read_string(struct device_node *np,
         return -ENOSYS;
 }
 
-static inline int of_property_read_string_index(struct device_node *np,
-                                                const char *propname, int index,
-                                                const char **out_string)
-{
-        return -ENOSYS;
-}
-
-static inline int of_property_count_strings(struct device_node *np,
-                                            const char *propname)
+static inline int of_property_read_string_helper(struct device_node *np,
+                                                 const char *propname,
+                                                 const char **out_strs, size_t sz, int index)
 {
         return -ENOSYS;
 }
@@ -668,6 +660,70 @@ static inline int of_property_count_u64_elems(const struct device_node *np,
 }
 
 /**
+ * of_property_read_string_array() - Read an array of strings from a multiple
+ * strings property.
+ * @np:         device node from which the property value is to be read.
+ * @propname:   name of the property to be searched.
+ * @out_strs:   output array of string pointers.
+ * @sz:         number of array elements to read.
+ *
+ * Search for a property in a device tree node and retrieve a list of
+ * terminated string values (pointer to data, not a copy) in that property.
+ *
+ * If @out_strs is NULL, the number of strings in the property is returned.
+ */
+static inline int of_property_read_string_array(struct device_node *np,
+                                                const char *propname, const char **out_strs,
+                                                size_t sz)
+{
+        return of_property_read_string_helper(np, propname, out_strs, sz, 0);
+}
+
+/**
+ * of_property_count_strings() - Find and return the number of strings from a
+ * multiple strings property.
+ * @np:         device node from which the property value is to be read.
+ * @propname:   name of the property to be searched.
+ *
+ * Search for a property in a device tree node and retrieve the number of null
+ * terminated string contain in it. Returns the number of strings on
+ * success, -EINVAL if the property does not exist, -ENODATA if property
+ * does not have a value, and -EILSEQ if the string is not null-terminated
+ * within the length of the property data.
+ */
+static inline int of_property_count_strings(struct device_node *np,
+                                            const char *propname)
+{
+        return of_property_read_string_helper(np, propname, NULL, 0, 0);
+}
+
+/**
+ * of_property_read_string_index() - Find and read a string from a multiple
+ * strings property.
+ * @np:         device node from which the property value is to be read.
+ * @propname:   name of the property to be searched.
+ * @index:      index of the string in the list of strings
+ * @out_string: pointer to null terminated return string, modified only if
+ *              return value is 0.
+ *
+ * Search for a property in a device tree node and retrieve a null
+ * terminated string value (pointer to data, not a copy) in the list of strings
+ * contained in that property.
+ * Returns 0 on success, -EINVAL if the property does not exist, -ENODATA if
+ * property does not have a value, and -EILSEQ if the string is not
+ * null-terminated within the length of the property data.
+ *
+ * The out_string pointer is modified only if a valid string can be decoded.
+ */
+static inline int of_property_read_string_index(struct device_node *np,
+                                                const char *propname,
+                                                int index, const char **output)
+{
+        int rc = of_property_read_string_helper(np, propname, output, 1, index);
+        return rc < 0 ? rc : 0;
+}
+
+/**
  * of_property_read_bool - Findfrom a property
  * @np:         device node from which the property value is to be read.
  * @propname:   name of the property to be searched.