commit 1c2859fb76bb4c4b2330585226cac43e1ac3f263
author Steven Moreland <smoreland@google.com> Tue Aug 04 22:03:55 2020 +0000
committer Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com> Tue Aug 04 22:03:55 2020 +0000
tree 683ce939869b5bcc48fcbe12948728fe475eeed4
parent d6297be44d310c8985ebb3b238ef5fc0c59634c9
parent 00cb016d89afa752d3fdebe60f9e7e27b45da2e6

Merge "libutils: check vsnprintf error" into oc-dev am: a03d37d542 am: d8801aaad8

Original change: https://googleplex-android-review.googlesource.com/c/platform/system/core/+/12254459

Change-Id: Ifa0692e4966e78f4e180a2efc53db991177b6006

libutils/String8.cpp

diff --git a/libutils/String8.cpp b/libutils/String8.cpp
index ad0e72e..8f9c9f7 100644
--- a/libutils/String8.cpp
+++ b/libutils/String8.cpp
@@ -346,8 +346,14 @@
     n = vsnprintf(NULL, 0, fmt, tmp_args);
     va_end(tmp_args);
 
-    if (n != 0) {
+    if (n < 0) return UNKNOWN_ERROR;
+
+    if (n > 0) {
         size_t oldLength = length();
+        if ((size_t)n > SIZE_MAX - 1 ||
+            oldLength > SIZE_MAX - (size_t)n - 1) {
+            return NO_MEMORY;
+        }
         char* buf = lockBuffer(oldLength + n);
         if (buf) {
             vsnprintf(buf + oldLength, n + 1, fmt, args);