hurd: Fix buffer overrun in __if_nametoindex

and building with mainline GCC which reports it.

	* sysdeps/mach/hurd/if_index.c (__if_nametoindex): Always end
	ifr.fr_name with a NUL caracter.

diff --git a/ChangeLog b/ChangeLog
index 36b022cb3552b0bfba01404a31493709fa57e75e..28fa4a5e6955a6450153230856f6e102c8438985 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2018-04-03  Samuel Thibault  <samuel.thibault@ens-lyon.org>
+
+       * sysdeps/mach/hurd/if_index.c (__if_nametoindex): Always end
+       ifr.fr_name with a NUL caracter.
+
 2018-04-03  Wilco Dijkstra  <wdijkstr@arm.com>
 
        * sysdeps/ieee754/dbl-64/s_sin.c (__sin): Cleanup ifdefs.

diff --git a/sysdeps/mach/hurd/if_index.c b/sysdeps/mach/hurd/if_index.c
index d637353d74bf50d2e9db300a4f0886b4ec18f0df..7f647b7036230bd3145c9daf00bb29201331a251 100644 (file)
--- a/sysdeps/mach/hurd/if_index.c
+++ b/sysdeps/mach/hurd/if_index.c
@@ -37,7 +37,9 @@ __if_nametoindex (const char *ifname)
   if (fd < 0)
     return 0;
 
-  strncpy (ifr.ifr_name, ifname, IFNAMSIZ);
+  strncpy (ifr.ifr_name, ifname, IFNAMSIZ - 1);
+  ifr.ifr_name[IFNAMESIZ - 1] = '\0';
+
   if (__ioctl (fd, SIOCGIFINDEX, &ifr) < 0)
     {
       int saved_errno = errno;