commit b73cea24f89621456c950b102d475ffbd4227334
author David Zeuthen <zeuthen@google.com> Fri Mar 06 09:57:53 2020 -0500
committer David Zeuthen <zeuthen@google.com> Mon Mar 30 11:08:44 2020 -0400
tree 07f3ec85703cc9695ce2a24b034109d6828849ea
parent 889cf371d3b35ca2d5993aec984431339f97a53b

avb_str_concat: Fail if 0 is passed for buf_size.

Bug: 130231426
Test: All AVB unit tests pass.
Merged-In: If27af10acebc7ae37409bee75e12b110904e46f6
Change-Id: I9bb847fa49489aa88c93f1e4ffe36cc03a767ce7

libavb/avb_util.c

diff --git a/libavb/avb_util.c b/libavb/avb_util.c
index 938ce4e..c0064cf 100644
--- a/libavb/avb_util.c
+++ b/libavb/avb_util.c
@@ -195,6 +195,12 @@
                     size_t str2_len) {
   uint64_t combined_len;
 
+  // Doesn't make sense to pass 0 for buf_size since there's
+  // no room for the terminating NUL byte.
+  if (buf_size == 0) {
+    return false;
+  }
+
   if (!avb_safe_add(&combined_len, str1_len, str2_len)) {
     avb_error("Overflow when adding string sizes.\n");
     return false;