ElfLinker::init() zero length implies 0x4000 blank bytes

src/linker.cpp

@@ -184,9 +184,10 @@ void ElfLinker::init(const void *pdata_v, int plen)
     }
     input[inputlen] = 0; // NUL terminate
 
-    output = new upx_byte[inputlen];
+    output = new upx_byte[inputlen ? inputlen : 0x4000];
     outputlen = 0;
 
+    if ((int)strlen("Sections:\n" "SYMBOL TABLE:\n" "RELOCATION RECORDS FOR ") < inputlen) {
         int pos = find(input, inputlen, "Sections:\n", 10);
         assert(pos != -1);
         char *psections = (char *) input + pos;
@@ -202,6 +203,7 @@ void ElfLinker::init(const void *pdata_v, int plen)
         preprocessRelocations(prelocs, (char*) input + inputlen);
         addLoader("*UND*");
     }
+}
 
 void ElfLinker::preprocessSections(char *start, char *end)
 {