Merge changes I17399680,I4952b3ab,I743b6227 am: f110de513b

Original change: https://android-review.googlesource.com/c/platform/frameworks/native/+/2613790

Change-Id: Ifde9832f31de6118f74a70aa89b7e7807fb1a50d
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
diff --git a/libs/binder/Parcel.cpp b/libs/binder/Parcel.cpp
index 0aca163..2c2a1b6 100644
--- a/libs/binder/Parcel.cpp
+++ b/libs/binder/Parcel.cpp
@@ -947,7 +947,10 @@
         threadState->setCallingWorkSourceUidWithoutPropagation(workSource);
         // vendor header
         int32_t header = readInt32();
-        if (header != kHeader) {
+
+        // fuzzers skip this check, because it is for protecting the underlying ABI, but
+        // we don't want it to reduce our coverage
+        if (header != kHeader && !mServiceFuzzing) {
             ALOGE("Expecting header 0x%x but found 0x%x. Mixing copies of libbinder?", kHeader,
                   header);
             return false;
@@ -966,10 +969,18 @@
             (!len || !memcmp(parcel_interface, interface, len * sizeof (char16_t)))) {
         return true;
     } else {
-        ALOGW("**** enforceInterface() expected '%s' but read '%s'",
-              String8(interface, len).string(),
-              String8(parcel_interface, parcel_interface_len).string());
-        return false;
+        if (mServiceFuzzing) {
+            // ignore. Theoretically, this could cause a few false positives, because
+            // people could assume things about getInterfaceDescriptor if they pass
+            // this point, but it would be extremely fragile. It's more important that
+            // we fuzz with the above things read from the Parcel.
+            return true;
+        } else {
+            ALOGW("**** enforceInterface() expected '%s' but read '%s'",
+                  String8(interface, len).string(),
+                  String8(parcel_interface, parcel_interface_len).string());
+            return false;
+        }
     }
 }
 
@@ -977,6 +988,10 @@
     mEnforceNoDataAvail = enforceNoDataAvail;
 }
 
+void Parcel::setServiceFuzzing() {
+    mServiceFuzzing = true;
+}
+
 binder::Status Parcel::enforceNoDataAvail() const {
     if (!mEnforceNoDataAvail) {
         return binder::Status::ok();
@@ -1722,7 +1737,9 @@
             do {
                 if (mDataPos < kernelFields->mObjects[nextObject] + sizeof(flat_binder_object)) {
                     // Requested info overlaps with an object
-                    ALOGE("Attempt to read from protected data in Parcel %p", this);
+                    if (!mServiceFuzzing) {
+                        ALOGE("Attempt to read from protected data in Parcel %p", this);
+                    }
                     return PERMISSION_DENIED;
                 }
                 nextObject++;
@@ -2092,7 +2109,11 @@
     size_t len;
     const char* str = readString8Inplace(&len);
     if (str) return String8(str, len);
-    ALOGE("Reading a NULL string not supported here.");
+
+    if (!mServiceFuzzing) {
+        ALOGE("Reading a NULL string not supported here.");
+    }
+
     return String8();
 }
 
@@ -2132,7 +2153,11 @@
     size_t len;
     const char16_t* str = readString16Inplace(&len);
     if (str) return String16(str, len);
-    ALOGE("Reading a NULL string not supported here.");
+
+    if (!mServiceFuzzing) {
+        ALOGE("Reading a NULL string not supported here.");
+    }
+
     return String16();
 }
 
@@ -2172,7 +2197,9 @@
 {
     status_t status = readNullableStrongBinder(val);
     if (status == OK && !val->get()) {
-        ALOGW("Expecting binder but got null!");
+        if (!mServiceFuzzing) {
+            ALOGW("Expecting binder but got null!");
+        }
         status = UNEXPECTED_NULL;
     }
     return status;
@@ -2237,9 +2264,11 @@
     if (const auto* rpcFields = maybeRpcFields()) {
         if (!std::binary_search(rpcFields->mObjectPositions.begin(),
                                 rpcFields->mObjectPositions.end(), mDataPos)) {
-            ALOGW("Attempt to read file descriptor from Parcel %p at offset %zu that is not in the "
-                  "object list",
-                  this, mDataPos);
+            if (!mServiceFuzzing) {
+                ALOGW("Attempt to read file descriptor from Parcel %p at offset %zu that is not in "
+                      "the object list",
+                      this, mDataPos);
+            }
             return BAD_TYPE;
         }
 
@@ -2497,8 +2526,11 @@
                 return obj;
             }
         }
-        ALOGW("Attempt to read object from Parcel %p at offset %zu that is not in the object list",
-             this, DPOS);
+        if (!mServiceFuzzing) {
+            ALOGW("Attempt to read object from Parcel %p at offset %zu that is not in the object "
+                  "list",
+                  this, DPOS);
+        }
     }
     return nullptr;
 }
@@ -3093,6 +3125,7 @@
     mDeallocZero = false;
     mOwner = nullptr;
     mEnforceNoDataAvail = true;
+    mServiceFuzzing = false;
 }
 
 void Parcel::scanForFds() const {
diff --git a/libs/binder/include/binder/Parcel.h b/libs/binder/include/binder/Parcel.h
index e28d374..15bb325 100644
--- a/libs/binder/include/binder/Parcel.h
+++ b/libs/binder/include/binder/Parcel.h
@@ -149,6 +149,10 @@
     // This Api is used by fuzzers to skip dataAvail checks.
     void setEnforceNoDataAvail(bool enforceNoDataAvail);
 
+    // When fuzzing, we want to remove certain ABI checks that cause significant
+    // lost coverage, and we also want to avoid logs that cost too much to write.
+    void setServiceFuzzing();
+
     void                freeData();
 
     size_t              objectsCount() const;
@@ -1330,6 +1334,7 @@
 
     // Set this to false to skip dataAvail checks.
     bool mEnforceNoDataAvail;
+    bool mServiceFuzzing;
 
     release_func        mOwner;
 
diff --git a/libs/binder/tests/parcel_fuzzer/libbinder_driver.cpp b/libs/binder/tests/parcel_fuzzer/libbinder_driver.cpp
index 0b3902d..24a9345 100644
--- a/libs/binder/tests/parcel_fuzzer/libbinder_driver.cpp
+++ b/libs/binder/tests/parcel_fuzzer/libbinder_driver.cpp
@@ -52,7 +52,8 @@
                     uint32_t flags = provider.ConsumeIntegral<uint32_t>();
                     Parcel data;
                     // for increased fuzz coverage
-                    data.setEnforceNoDataAvail(provider.ConsumeBool());
+                    data.setEnforceNoDataAvail(false);
+                    data.setServiceFuzzing();
 
                     sp<IBinder> target = options.extraBinders.at(
                             provider.ConsumeIntegralInRange<size_t>(0,
@@ -73,7 +74,8 @@
 
                     Parcel reply;
                     // for increased fuzz coverage
-                    reply.setEnforceNoDataAvail(provider.ConsumeBool());
+                    reply.setEnforceNoDataAvail(false);
+                    reply.setServiceFuzzing();
                     (void)target->transact(code, data, &reply, flags);
 
                     // feed back in binders and fds that are returned from the service, so that