1 files changed, 28 insertions, 3 deletions
diff --git a/libs/binder/Parcel.cpp b/libs/binder/Parcel.cpp
index 9bba369ee4..8087443720 100644
--- a/libs/binder/Parcel.cpp
+++ b/libs/binder/Parcel.cpp
@@ -1477,6 +1477,31 @@ data_unsorted:
     goto data_sorted;
 }
 
+status_t Parcel::readVectorSizeWithCoarseBoundCheck(int32_t *size) const {
+    int32_t requestedSize;
+    const status_t status = readInt32(&requestedSize);
+    if (status != NO_ERROR) return status;
+
+    // We permit negative sizes, which indicate presence of a nullable vector,
+    // i.e. a vector embedded in std::optional, std::unique_ptr, or std::shared_ptr.
+    if (requestedSize > 0) {
+        // Check if there are fewer bytes than vector elements.
+        // A lower bound is 1 byte per element, satisfied by some enum and int8_t and uint8_t.
+        const size_t availableBytes = dataAvail();
+        if (static_cast<size_t>(requestedSize) > availableBytes) {
+            // We have a size that is greater than the number of bytes available.
+            // On bounds failure we do not 'rewind' position by 4 bytes of the size already read.
+            ALOGW("%s: rejecting out of bounds vector size (requestedSize):%d "
+                    "Parcel{dataAvail:%zu mDataSize:%zu mDataPos:%zu mDataCapacity:%zu}",
+                    __func__, requestedSize, availableBytes, mDataSize, mDataPos, mDataCapacity);
+            return BAD_VALUE;
+        }
+    }
+
+    *size = requestedSize;
+    return NO_ERROR;
+}
+
 status_t Parcel::read(void* outData, size_t len) const
 {
     if (len > INT32_MAX) {
@@ -1699,7 +1724,7 @@ status_t Parcel::readDoubleVector(std::vector<double>* val) const {
 status_t Parcel::readBoolVector(std::optional<std::vector<bool>>* val) const {
     const int32_t start = dataPosition();
     int32_t size;
-    status_t status = readInt32(&size);
+    status_t status = readVectorSizeWithCoarseBoundCheck(&size);
     val->reset();
 
     if (status != OK || size < 0) {
@@ -1721,7 +1746,7 @@ status_t Parcel::readBoolVector(std::optional<std::vector<bool>>* val) const {
 status_t Parcel::readBoolVector(std::unique_ptr<std::vector<bool>>* val) const {
     const int32_t start = dataPosition();
     int32_t size;
-    status_t status = readInt32(&size);
+    status_t status = readVectorSizeWithCoarseBoundCheck(&size);
     val->reset();
 
     if (status != OK || size < 0) {
@@ -1742,7 +1767,7 @@ status_t Parcel::readBoolVector(std::unique_ptr<std::vector<bool>>* val) const {
 
 status_t Parcel::readBoolVector(std::vector<bool>* val) const {
     int32_t size;
-    status_t status = readInt32(&size);
+    status_t status = readVectorSizeWithCoarseBoundCheck(&size);
 
     if (status != OK) {
         return status;