Fix addition/overflow checks.
For unsigned arithmetic, use:
(a + b < a) to detect whether a+b wraps
(a > c / b) to detect whether a*b > c
Bug: 120078455
Test: builds and boots
Change-Id: Ic4f4d44f7c0656caa115f90f4cfa130192914949
diff --git a/libs/binder/BufferedTextOutput.cpp b/libs/binder/BufferedTextOutput.cpp
index fb424fd..824b56b 100644
--- a/libs/binder/BufferedTextOutput.cpp
+++ b/libs/binder/BufferedTextOutput.cpp
@@ -49,9 +49,10 @@
}
status_t append(const char* txt, size_t len) {
+ if (len > SIZE_MAX - bufferPos) return NO_MEMORY; // overflow
if ((len+bufferPos) > bufferSize) {
+ if ((len + bufferPos) > SIZE_MAX / 3) return NO_MEMORY; // overflow
size_t newSize = ((len+bufferPos)*3)/2;
- if (newSize < (len+bufferPos)) return NO_MEMORY; // overflow
void* b = realloc(buffer, newSize);
if (!b) return NO_MEMORY;
buffer = (char*)b;