Proper bounds checking in LocaleValue
Bug: 204078909
Test: manual
Change-Id: Ic5fc30a9e84e46d50bd13b6bb3c630c8eeaa430c
diff --git a/libs/androidfw/Locale.cpp b/libs/androidfw/Locale.cpp
index 3eedda8..d87a3ce 100644
--- a/libs/androidfw/Locale.cpp
+++ b/libs/androidfw/Locale.cpp
@@ -29,40 +29,33 @@
namespace android {
-void LocaleValue::set_language(const char* language_chars) {
+template <size_t N, class Transformer>
+static void safe_transform_copy(const char* source, char (&dest)[N], Transformer t) {
size_t i = 0;
- while ((*language_chars) != '\0') {
- language[i++] = ::tolower(*language_chars);
- language_chars++;
+ while (i < N && (*source) != '\0') {
+ dest[i++] = t(i, *source);
+ source++;
}
+ while (i < N) {
+ dest[i++] = '\0';
+ }
+}
+
+void LocaleValue::set_language(const char* language_chars) {
+ safe_transform_copy(language_chars, language, [](size_t, char c) { return ::tolower(c); });
}
void LocaleValue::set_region(const char* region_chars) {
- size_t i = 0;
- while ((*region_chars) != '\0') {
- region[i++] = ::toupper(*region_chars);
- region_chars++;
- }
+ safe_transform_copy(region_chars, region, [](size_t, char c) { return ::toupper(c); });
}
void LocaleValue::set_script(const char* script_chars) {
- size_t i = 0;
- while ((*script_chars) != '\0') {
- if (i == 0) {
- script[i++] = ::toupper(*script_chars);
- } else {
- script[i++] = ::tolower(*script_chars);
- }
- script_chars++;
- }
+ safe_transform_copy(script_chars, script,
+ [](size_t i, char c) { return i ? ::tolower(c) : ::toupper(c); });
}
void LocaleValue::set_variant(const char* variant_chars) {
- size_t i = 0;
- while ((*variant_chars) != '\0') {
- variant[i++] = *variant_chars;
- variant_chars++;
- }
+ safe_transform_copy(variant_chars, variant, [](size_t, char c) { return c; });
}
static inline bool is_alpha(const std::string& str) {
@@ -234,6 +227,10 @@
return static_cast<ssize_t>(iter - start_iter);
}
+// Make sure the following memcpy's are properly sized.
+static_assert(sizeof(ResTable_config::localeScript) == sizeof(LocaleValue::script));
+static_assert(sizeof(ResTable_config::localeVariant) == sizeof(LocaleValue::variant));
+
void LocaleValue::InitFromResTable(const ResTable_config& config) {
config.unpackLanguage(language);
config.unpackRegion(region);