[src/trunk]: src/sys/arch/newsmips/apbus Avoid memory leak in sonic_get.

[riastradh <riastradh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/28cb51a18476
branches:  trunk
changeset: 355436:28cb51a18476
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Sat Jul 29 02:21:30 2017 +0000

description:
Avoid memory leak in sonic_get.

If this is the first time around, top is null and nothing else will
free m.

>From Ilja Van Sprundel.

diffstat:

 sys/arch/newsmips/apbus/if_sn.c |  9 ++++++---
 1 files changed, 6 insertions(+), 3 deletions(-)

diffs (30 lines):

diff -r a97435ff381e -r 28cb51a18476 sys/arch/newsmips/apbus/if_sn.c
--- a/sys/arch/newsmips/apbus/if_sn.c   Sat Jul 29 02:17:44 2017 +0000
+++ b/sys/arch/newsmips/apbus/if_sn.c   Sat Jul 29 02:21:30 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_sn.c,v 1.38 2017/02/22 09:45:16 nonaka Exp $        */
+/*     $NetBSD: if_sn.c,v 1.39 2017/07/29 02:21:30 riastradh Exp $     */
 
 /*
  * National Semiconductor  DP8393X SONIC Driver
@@ -16,7 +16,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_sn.c,v 1.38 2017/02/22 09:45:16 nonaka Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_sn.c,v 1.39 2017/07/29 02:21:30 riastradh Exp $");
 
 #include "opt_inet.h"
 
@@ -1090,7 +1090,10 @@
                if (datalen >= MINCLSIZE) {
                        MCLGET(m, M_DONTWAIT);
                        if ((m->m_flags & M_EXT) == 0) {
-                               if (top) m_freem(top);
+                               if (top)
+                                       m_freem(top);
+                               else
+                                       m_freem(m);
                                return 0;
                        }
                        len = MCLBYTES;