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authorLinus Torvalds <torvalds@linux-foundation.org>2014-11-09 14:33:49 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-11-09 14:33:49 -0800
commita3157809772c4a5256ef68a4d5b21ea4ecc80ad4 (patch)
tree1269b7442c98571c9a4bce5f02e2c7cc6e6d1d40
parentc4c23fb6f2b17c922b493f79cf27a0d32397f461 (diff)
parenta87fa1d81a9fb5e9adca9820e16008c40ad09f33 (diff)
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
-rw-r--r--drivers/of/base.c88
-rw-r--r--drivers/of/selftest.c66
-rw-r--r--drivers/of/testcase-data/tests-phandle.dtsi2
-rw-r--r--include/linux/of.h84
4 files changed, 154 insertions, 86 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 2305dc0382bc..3823edf2d012 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -1280,52 +1280,6 @@ int of_property_read_string(struct device_node *np, const char *propname,
EXPORT_SYMBOL_GPL(of_property_read_string);
/**
- * 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.
- */
-int of_property_read_string_index(struct device_node *np, const char *propname,
- int index, const char **output)
-{
- struct property *prop = of_find_property(np, propname, NULL);
- int i = 0;
- size_t l = 0, total = 0;
- const char *p;
-
- if (!prop)
- return -EINVAL;
- if (!prop->value)
- return -ENODATA;
- if (strnlen(prop->value, prop->length) >= prop->length)
- return -EILSEQ;
-
- p = prop->value;
-
- for (i = 0; total < prop->length; total += l, p += l) {
- l = strlen(p) + 1;
- if (i++ == index) {
- *output = p;
- return 0;
- }
- }
- return -ENODATA;
-}
-EXPORT_SYMBOL_GPL(of_property_read_string_index);
-
-/**
* of_property_match_string() - Find string in a list and return index
* @np: pointer to node containing string list property
* @propname: string list property name
@@ -1351,7 +1305,7 @@ int of_property_match_string(struct device_node *np, const char *propname,
end = p + prop->length;
for (i = 0; p < end; i++, p += l) {
- l = strlen(p) + 1;
+ l = strnlen(p, end - p) + 1;
if (p + l > end)
return -EILSEQ;
pr_debug("comparing %s with %s\n", string, p);
@@ -1363,39 +1317,41 @@ int of_property_match_string(struct device_node *np, const char *propname,
EXPORT_SYMBOL_GPL(of_property_match_string);
/**
- * of_property_count_strings - Find and return the number of strings from a
- * multiple strings property.
+ * of_property_read_string_util() - Utility helper for parsing string properties
* @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.
+ * @skip: Number of strings to skip over at beginning of list.
*
- * 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.
+ * Don't call this function directly. It is a utility helper for the
+ * of_property_read_string*() family of functions.
*/
-int of_property_count_strings(struct device_node *np, const char *propname)
+int of_property_read_string_helper(struct device_node *np, const char *propname,
+ const char **out_strs, size_t sz, int skip)
{
struct property *prop = of_find_property(np, propname, NULL);
- int i = 0;
- size_t l = 0, total = 0;
- const char *p;
+ int l = 0, i = 0;
+ const char *p, *end;
if (!prop)
return -EINVAL;
if (!prop->value)
return -ENODATA;
- if (strnlen(prop->value, prop->length) >= prop->length)
- return -EILSEQ;
-
p = prop->value;
+ end = p + prop->length;
- for (i = 0; total < prop->length; total += l, p += l, i++)
- l = strlen(p) + 1;
-
- return i;
+ for (i = 0; p < end && (!out_strs || i < skip + sz); i++, p += l) {
+ l = strnlen(p, end - p) + 1;
+ if (p + l > end)
+ return -EILSEQ;
+ if (out_strs && i >= skip)
+ *out_strs++ = p;
+ }
+ i -= skip;
+ return i <= 0 ? -ENODATA : i;
}
-EXPORT_SYMBOL_GPL(of_property_count_strings);
+EXPORT_SYMBOL_GPL(of_property_read_string_helper);
void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
{
diff --git a/drivers/of/selftest.c b/drivers/of/selftest.c
index 78001270a598..11b873c54a77 100644
--- a/drivers/of/selftest.c
+++ b/drivers/of/selftest.c
@@ -339,8 +339,9 @@ static void __init of_selftest_parse_phandle_with_args(void)
selftest(rc == -EINVAL, "expected:%i got:%i\n", -EINVAL, rc);
}
-static void __init of_selftest_property_match_string(void)
+static void __init of_selftest_property_string(void)
{
+ const char *strings[4];
struct device_node *np;
int rc;
@@ -357,13 +358,66 @@ static void __init of_selftest_property_match_string(void)
rc = of_property_match_string(np, "phandle-list-names", "third");
selftest(rc == 2, "third expected:0 got:%i\n", rc);
rc = of_property_match_string(np, "phandle-list-names", "fourth");
- selftest(rc == -ENODATA, "unmatched string; rc=%i", rc);
+ selftest(rc == -ENODATA, "unmatched string; rc=%i\n", rc);
rc = of_property_match_string(np, "missing-property", "blah");
- selftest(rc == -EINVAL, "missing property; rc=%i", rc);
+ selftest(rc == -EINVAL, "missing property; rc=%i\n", rc);
rc = of_property_match_string(np, "empty-property", "blah");
- selftest(rc == -ENODATA, "empty property; rc=%i", rc);
+ selftest(rc == -ENODATA, "empty property; rc=%i\n", rc);
rc = of_property_match_string(np, "unterminated-string", "blah");
- selftest(rc == -EILSEQ, "unterminated string; rc=%i", rc);
+ selftest(rc == -EILSEQ, "unterminated string; rc=%i\n", rc);
+
+ /* of_property_count_strings() tests */
+ rc = of_property_count_strings(np, "string-property");
+ selftest(rc == 1, "Incorrect string count; rc=%i\n", rc);
+ rc = of_property_count_strings(np, "phandle-list-names");
+ selftest(rc == 3, "Incorrect string count; rc=%i\n", rc);
+ rc = of_property_count_strings(np, "unterminated-string");
+ selftest(rc == -EILSEQ, "unterminated string; rc=%i\n", rc);
+ rc = of_property_count_strings(np, "unterminated-string-list");
+ selftest(rc == -EILSEQ, "unterminated string array; rc=%i\n", rc);
+
+ /* of_property_read_string_index() tests */
+ rc = of_property_read_string_index(np, "string-property", 0, strings);
+ selftest(rc == 0 && !strcmp(strings[0], "foobar"), "of_property_read_string_index() failure; rc=%i\n", rc);
+ strings[0] = NULL;
+ rc = of_property_read_string_index(np, "string-property", 1, strings);
+ selftest(rc == -ENODATA && strings[0] == NULL, "of_property_read_string_index() failure; rc=%i\n", rc);
+ rc = of_property_read_string_index(np, "phandle-list-names", 0, strings);
+ selftest(rc == 0 && !strcmp(strings[0], "first"), "of_property_read_string_index() failure; rc=%i\n", rc);
+ rc = of_property_read_string_index(np, "phandle-list-names", 1, strings);
+ selftest(rc == 0 && !strcmp(strings[0], "second"), "of_property_read_string_index() failure; rc=%i\n", rc);
+ rc = of_property_read_string_index(np, "phandle-list-names", 2, strings);
+ selftest(rc == 0 && !strcmp(strings[0], "third"), "of_property_read_string_index() failure; rc=%i\n", rc);
+ strings[0] = NULL;
+ rc = of_property_read_string_index(np, "phandle-list-names", 3, strings);
+ selftest(rc == -ENODATA && strings[0] == NULL, "of_property_read_string_index() failure; rc=%i\n", rc);
+ strings[0] = NULL;
+ rc = of_property_read_string_index(np, "unterminated-string", 0, strings);
+ selftest(rc == -EILSEQ && strings[0] == NULL, "of_property_read_string_index() failure; rc=%i\n", rc);
+ rc = of_property_read_string_index(np, "unterminated-string-list", 0, strings);
+ selftest(rc == 0 && !strcmp(strings[0], "first"), "of_property_read_string_index() failure; rc=%i\n", rc);
+ strings[0] = NULL;
+ rc = of_property_read_string_index(np, "unterminated-string-list", 2, strings); /* should fail */
+ selftest(rc == -EILSEQ && strings[0] == NULL, "of_property_read_string_index() failure; rc=%i\n", rc);
+ strings[1] = NULL;
+
+ /* of_property_read_string_array() tests */
+ rc = of_property_read_string_array(np, "string-property", strings, 4);
+ selftest(rc == 1, "Incorrect string count; rc=%i\n", rc);
+ rc = of_property_read_string_array(np, "phandle-list-names", strings, 4);
+ selftest(rc == 3, "Incorrect string count; rc=%i\n", rc);
+ rc = of_property_read_string_array(np, "unterminated-string", strings, 4);
+ selftest(rc == -EILSEQ, "unterminated string; rc=%i\n", rc);
+ /* -- An incorrectly formed string should cause a failure */
+ rc = of_property_read_string_array(np, "unterminated-string-list", strings, 4);
+ selftest(rc == -EILSEQ, "unterminated string array; rc=%i\n", rc);
+ /* -- parsing the correctly formed strings should still work: */
+ strings[2] = NULL;
+ rc = of_property_read_string_array(np, "unterminated-string-list", strings, 2);
+ selftest(rc == 2 && strings[2] == NULL, "of_property_read_string_array() failure; rc=%i\n", rc);
+ strings[1] = NULL;
+ rc = of_property_read_string_array(np, "phandle-list-names", strings, 1);
+ selftest(rc == 1 && strings[1] == NULL, "Overwrote end of string array; rc=%i, str='%s'\n", rc, strings[1]);
}
#define propcmp(p1, p2) (((p1)->length == (p2)->length) && \
@@ -881,7 +935,7 @@ static int __init of_selftest(void)
of_selftest_find_node_by_name();
of_selftest_dynamic();
of_selftest_parse_phandle_with_args();
- of_selftest_property_match_string();
+ of_selftest_property_string();
of_selftest_property_copy();
of_selftest_changeset();
of_selftest_parse_interrupts();
diff --git a/drivers/of/testcase-data/tests-phandle.dtsi b/drivers/of/testcase-data/tests-phandle.dtsi
index ce0fe083d406..5b1527e8a7fb 100644
--- a/drivers/of/testcase-data/tests-phandle.dtsi
+++ b/drivers/of/testcase-data/tests-phandle.dtsi
@@ -39,7 +39,9 @@
phandle-list-bad-args = <&provider2 1 0>,
<&provider3 0>;
empty-property;
+ string-property = "foobar";
unterminated-string = [40 41 42 43];
+ unterminated-string-list = "first", "second", [40 41 42 43];
};
};
};
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.