--- Coreutils2/coreutils-8.28/src/sort.c        2017-09-01 00:11:03.000000000 -0700
+++ Coreutils/coreutils-8.28/src/sort.c 2018-12-04 17:17:25.960715505 -0800
@@ -108,6 +108,9 @@ struct rlimit { size_t rlim_cur; };
 # define DEFAULT_TMPDIR "/tmp"
 #endif
 
+#define IS_UNSORTABLE_FILE_TYPE(Mode) (S_ISCHR (Mode) \
+  || S_ISBLK (Mode) || S_ISFIFO (Mode))
+
 /* Maximum number of lines to merge every time a NODE is taken from
    the merge queue.  Node is at LEVEL in the binary merge tree,
    and is responsible for merging TOTAL lines. */
@@ -946,6 +949,7 @@ static FILE *
 stream_open (char const *file, char const *how)
 {
   FILE *fp;
+  struct stat st;
 
   if (*how == 'r')
     {
@@ -956,6 +960,14 @@ stream_open (char const *file, char cons
         }
       else
         {
+          /* Check for unsupported file types  */
+          stat (file, &st);
+          if (IS_UNSORTABLE_FILE_TYPE (st.st_mode))
+            {
+              die (SORT_FAILURE, errno, _("cannot sort special file %s"),
+                 quoteaf (file));
+            }
+
           int fd = open (file, O_RDONLY | O_CLOEXEC);
           fp = fd < 0 ? NULL : fdopen (fd, how);
         }