issue-644: fix possible out-of-bounds access in GetenvBeforeMain

As suggested by user Ivan L.

1 files changed, 3 insertions, 0 deletions

diff --git a/src/base/sysinfo.cc b/src/base/sysinfo.cc
index ca76328..cad751b 100644
--- a/src/base/sysinfo.cc
+++ b/src/base/sysinfo.cc
@@ -124,6 +124,9 @@ const char* GetenvBeforeMain(const char* name) {
   if (__environ) {            // can exist but be NULL, if statically linked
     const int namelen = strlen(name);
     for (char** p = __environ; *p; p++) {
+      if (strlen(*p) < namelen) {
+        continue;
+      }
       if (!memcmp(*p, name, namelen) && (*p)[namelen] == '=')  // it's a match
         return *p + namelen+1;                                 // point after =
     }