Bug 1167888 - better string length check in nsZipArchive::BuildFileList, r=smaug

2015-06-04 15:04:10 +01:00
parent 37bfee02ee
commit e64d701ef2
1 changed files with 6 additions and 1 deletions
--- a/modules/libjar/nsZipArchive.cpp
+++ b/modules/libjar/nsZipArchive.cpp
@@ -644,8 +644,13 @@ MOZ_WIN_MEM_TRY_BEGIN
  if (!centralOffset)
    return NS_ERROR_FILE_CORRUPTED;

-  //-- Read the central directory headers
  buf = startp + centralOffset;
+
+  // avoid overflow of startp + centralOffset.
+  if (buf < startp)
+    return NS_ERROR_FILE_CORRUPTED;
+
+  //-- Read the central directory headers
  uint32_t sig = 0;
  while (buf + int32_t(sizeof(uint32_t)) <= endp &&
         (sig = xtolong(buf)) == CENTRALSIG) {