diff -uNr lz4-1.8.3.orig/lib/lz4.c lz4-1.8.3/lib/lz4.c
--- lz4-1.8.3.orig/lib/lz4.c	2019-11-08 08:27:51.607783857 +0000
+++ lz4-1.8.3/lib/lz4.c	2019-11-08 08:29:29.582497178 +0000
@@ -1432,6 +1432,8 @@
     const BYTE* const shortiend = iend - (endOnInput ? 14 : 8) /*maxLL*/ - 2 /*offset*/;
     const BYTE* const shortoend = oend - (endOnInput ? 14 : 8) /*maxLL*/ - 18 /*maxML*/;
 
+    if (src == NULL) { return -1; }
+
     DEBUGLOG(5, "LZ4_decompress_generic (srcSize:%i, dstSize:%i)", srcSize, outputSize);
 
     /* Special cases */