From 6984eaa9f4a369228259047c2f797d022afb8f3b Mon Sep 17 00:00:00 2001
From: Christopher Tate <ctate@google.com>
Date: Mon, 7 Jun 2021 15:02:45 -0700
Subject: [PATCH] Fix side effects of trace-ipc and dumpheap commands

These shell commands were implicitly deleting any client-named file for
which the system uid had deletion capability.  They no longer do this,
instead using only the client's own capabilities and file manipulation
modes.

Bug: 185398942
Test: manual "adb shell cmd activity dumpheap system_server /data/system/last-fstrim"
Test: atest CtsPermissionTestCases:ShellCommandPermissionTest
Merged-In: Ie61ab2c3f4bfbd04de09ca99c1116d1129461e8f
Change-Id: Ie61ab2c3f4bfbd04de09ca99c1116d1129461e8f
---
 .../com/android/server/am/ActivityManagerShellCommand.java | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/services/core/java/com/android/server/am/ActivityManagerShellCommand.java b/services/core/java/com/android/server/am/ActivityManagerShellCommand.java
index 9575fddf04f20..7b7e73e6f8f4e 100644
--- a/services/core/java/com/android/server/am/ActivityManagerShellCommand.java
+++ b/services/core/java/com/android/server/am/ActivityManagerShellCommand.java
@@ -60,7 +60,6 @@ import com.android.internal.util.HexDump;
 import com.android.internal.util.Preconditions;
 
 import java.io.BufferedReader;
-import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
@@ -660,8 +659,7 @@ final class ActivityManagerShellCommand extends ShellCommand {
             return -1;
         }
 
-        File file = new File(filename);
-        file.delete();
+        // Writes an error message to stderr on failure
         ParcelFileDescriptor fd = openOutputFileForSystem(filename);
         if (fd == null) {
             return -1;
@@ -812,8 +810,7 @@ final class ActivityManagerShellCommand extends ShellCommand {
         String process = getNextArgRequired();
         String heapFile = getNextArgRequired();
 
-        File file = new File(heapFile);
-        file.delete();
+        // Writes an error message to stderr on failure
         ParcelFileDescriptor fd = openOutputFileForSystem(heapFile);
         if (fd == null) {
             return -1;