svn commit: r328551 - head/usr.sbin/pppctl

[Pedro F. Giffuni]

Author: pfg
Date: Mon Jan 29 14:23:44 2018
New Revision: 328551
URL: https://svnweb.freebsd.org/changeset/base/328551

Log:
  pppctl88) Avoid strcpy() copies on overlapping string.
  
  This may lead to unpredicatable behaviour on different platforms or C
  library implementations. Use an intermediate variable.
  
  Obtained from:	DragonFlyBSD (git a861a526)

Modified:
  head/usr.sbin/pppctl/pppctl.c

Modified: head/usr.sbin/pppctl/pppctl.c
==============================================================================
--- head/usr.sbin/pppctl/pppctl.c	Mon Jan 29 14:15:44 2018	(r328550)
+++ head/usr.sbin/pppctl/pppctl.c	Mon Jan 29 14:23:44 2018	(r328551)
@@ -121,6 +121,7 @@ static int
 Receive(int fd, int display)
 {
     static char Buffer[LINELEN];
+    char temp[sizeof(Buffer)];
     struct timeval t;
     int Result;
     char *last;
@@ -185,7 +186,8 @@ Receive(int fd, int display)
             else
                 flush = last - Buffer + 1;
             write(STDOUT_FILENO, Buffer, flush);
-            strcpy(Buffer, Buffer + flush);
+	    strcpy(temp, Buffer + flush);
+	    strcpy(Buffer, temp);
             len -= flush;
         }
         if ((Result = select(fd + 1, &f, NULL, NULL, &t)) <= 0) {