commit f183fdd024bfa87e929219ac537b7090eabae9b1
author Steven Moreland <smoreland@google.com> Tue Oct 27 00:12:12 2020 +0000
committer Steven Moreland <smoreland@google.com> Mon Nov 09 21:05:06 2020 +0000
tree 4ec6148be9104ef1e4e6b7be15d15599db2ab64b
parent b40b64d0f8740dfa06da50b56ed48bf496dee4f8

libbinder: support TF_CLEAR_BUF

This flag instructs the kernel to clear transactions from send/reply
buffers for certain transactions which may contain sensitive data, as a
security precaution.

Bug: 171501998
Test: binderLibTest (only checks there is no error)
Change-Id: I69d732e5cc2b15472dc52d47c66716bc1b3be6ae

libs/binder/Binder.cpp

diff --git a/libs/binder/Binder.cpp b/libs/binder/Binder.cpp
index 6ca3b16..f2d223d 100644
--- a/libs/binder/Binder.cpp
+++ b/libs/binder/Binder.cpp
@@ -173,6 +173,10 @@
 {
     data.setDataPosition(0);
 
+    if (reply != nullptr && (flags & FLAG_CLEAR_BUF)) {
+        reply->markSensitive();
+    }
+
     status_t err = NO_ERROR;
     switch (code) {
         case PING_TRANSACTION: