Process: Fix communication with zygote.
Don't write partial requests, and don't return (or throw) early after
partially reading a response.
bug: 30143607
Change-Id: I5881fdd5e81023cd21fb4d23a471a5031987a1f1
(cherry picked from commit 448be0a62209c977593d81617853a8a428d013df)
diff --git a/core/java/android/os/Process.java b/core/java/android/os/Process.java
index f664e70..21b3f6e 100644
--- a/core/java/android/os/Process.java
+++ b/core/java/android/os/Process.java
@@ -559,6 +559,15 @@
ZygoteState zygoteState, ArrayList<String> args)
throws ZygoteStartFailedEx {
try {
+ // Throw early if any of the arguments are malformed. This means we can
+ // avoid writing a partial response to the zygote.
+ int sz = args.size();
+ for (int i = 0; i < sz; i++) {
+ if (args.get(i).indexOf('\n') >= 0) {
+ throw new ZygoteStartFailedEx("embedded newlines not allowed");
+ }
+ }
+
/**
* See com.android.internal.os.ZygoteInit.readArgumentList()
* Presently the wire format to the zygote process is:
@@ -575,13 +584,8 @@
writer.write(Integer.toString(args.size()));
writer.newLine();
- int sz = args.size();
for (int i = 0; i < sz; i++) {
String arg = args.get(i);
- if (arg.indexOf('\n') >= 0) {
- throw new ZygoteStartFailedEx(
- "embedded newlines not allowed");
- }
writer.write(arg);
writer.newLine();
}
@@ -590,11 +594,16 @@
// Should there be a timeout on this?
ProcessStartResult result = new ProcessStartResult();
+
+ // Always read the entire result from the input stream to avoid leaving
+ // bytes in the stream for future process starts to accidentally stumble
+ // upon.
result.pid = inputStream.readInt();
+ result.usingWrapper = inputStream.readBoolean();
+
if (result.pid < 0) {
throw new ZygoteStartFailedEx("fork() failed");
}
- result.usingWrapper = inputStream.readBoolean();
return result;
} catch (IOException ex) {
zygoteState.close();
