init/util.cpp: don't return a negative unsigned value
android_name_to_id() returns -1U on error, which causes a
crash when the following clang options are enabled:
-fsanitize=signed-integer-overflow,unsigned-integer-overflow
-ftrap-function=abort
-fsanitize-undefined-trap-on-error
Rather than returning a negative unsigned value (which doesn't
make a lot of sense, IMHO), return a positive unsigned value.
While we're here, add logging on decode_uid failures.
Bug: 21880301
Change-Id: I652e4c1daa07c7494cceca2b4e1656b9158f2604
diff --git a/init/util.cpp b/init/util.cpp
index 8216892..7f29e94 100644
--- a/init/util.cpp
+++ b/init/util.cpp
@@ -47,7 +47,7 @@
/*
* android_name_to_id - returns the integer uid/gid associated with the given
- * name, or -1U on error.
+ * name, or UINT_MAX on error.
*/
static unsigned int android_name_to_id(const char *name)
{
@@ -59,27 +59,35 @@
return info[n].aid;
}
- return -1U;
+ return UINT_MAX;
}
-/*
- * decode_uid - decodes and returns the given string, which can be either the
- * numeric or name representation, into the integer uid or gid. Returns -1U on
- * error.
- */
-unsigned int decode_uid(const char *s)
+static unsigned int do_decode_uid(const char *s)
{
unsigned int v;
if (!s || *s == '\0')
- return -1U;
+ return UINT_MAX;
if (isalpha(s[0]))
return android_name_to_id(s);
errno = 0;
v = (unsigned int) strtoul(s, 0, 0);
if (errno)
- return -1U;
+ return UINT_MAX;
+ return v;
+}
+
+/*
+ * decode_uid - decodes and returns the given string, which can be either the
+ * numeric or name representation, into the integer uid or gid. Returns
+ * UINT_MAX on error.
+ */
+unsigned int decode_uid(const char *s) {
+ unsigned int v = do_decode_uid(s);
+ if (v == UINT_MAX) {
+ ERROR("decode_uid: Unable to find UID for '%s'. Returning UINT_MAX\n", s);
+ }
return v;
}
diff --git a/init/util_test.cpp b/init/util_test.cpp
index 5b3ab50..228954b 100644
--- a/init/util_test.cpp
+++ b/init/util_test.cpp
@@ -38,6 +38,6 @@
TEST(util, decode_uid) {
EXPECT_EQ(0U, decode_uid("root"));
- EXPECT_EQ(-1U, decode_uid("toot"));
+ EXPECT_EQ(UINT_MAX, decode_uid("toot"));
EXPECT_EQ(123U, decode_uid("123"));
}