bootstat: better validation of battery level (shutdown,battery)
Replace simple strtoull with loop that ensures no leading zeros.
Restrict size of value buffer being checked as allocation was
going to end of retrieved buffer, which can cause unnecessary
memory pressure during boot.
Test: system/core/bootstat/boot_reason_test.sh
Bug: 63736262
Change-Id: Ifdc1d4fd3a73794c001577024ce7cbfde9c25028
diff --git a/bootstat/bootstat.cpp b/bootstat/bootstat.cpp
index 07d410c..cdb4b9b 100644
--- a/bootstat/bootstat.cpp
+++ b/bootstat/bootstat.cpp
@@ -508,10 +508,16 @@
size_t pos = content.rfind(battery); // last one
std::string digits;
if (pos != std::string::npos) {
- digits = content.substr(pos + strlen(battery));
+ digits = content.substr(pos + strlen(battery), strlen("100 "));
}
- char* endptr = NULL;
- unsigned long long level = strtoull(digits.c_str(), &endptr, 10);
+ const char* endptr = digits.c_str();
+ unsigned level = 0;
+ while (::isdigit(*endptr)) {
+ level *= 10;
+ level += *endptr++ - '0';
+ // make sure no leading zeros, except zero itself, and range check.
+ if ((level == 0) || (level > 100)) break;
+ }
if ((level <= 100) && (endptr != digits.c_str()) && (*endptr == ' ')) {
LOG(INFO) << "Battery level at shutdown " << level << "%";
if (level <= battery_dead_threshold) {
@@ -552,10 +558,16 @@
pos = content.find(match); // The first one it finds.
if (pos != std::string::npos) {
- digits = content.substr(pos + strlen(match));
+ digits = content.substr(pos + strlen(match), strlen("100 "));
}
- endptr = NULL;
- level = strtoull(digits.c_str(), &endptr, 10);
+ endptr = digits.c_str();
+ level = 0;
+ while (::isdigit(*endptr)) {
+ level *= 10;
+ level += *endptr++ - '0';
+ // make sure no leading zeros, except zero itself, and range check.
+ if ((level == 0) || (level > 100)) break;
+ }
if ((level <= 100) && (endptr != digits.c_str()) && (*endptr == ' ')) {
LOG(INFO) << "Battery level at startup " << level << "%";
if (level <= battery_dead_threshold) {