[src/trunk]: src/sys/kern The mbuf is freed by the protocol even on error, so...

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

details:   https://anonhg.NetBSD.org/src/rev/3677e83640f6
branches:  trunk
changeset: 818782:3677e83640f6
user:      maxv <maxv%NetBSD.org@localhost>
date:      Mon Oct 31 15:27:24 2016 +0000

description:
The mbuf is freed by the protocol even on error, so always NULL the pointer
instead of double-freeing it. Indirectly pointed out by Mootja.

diffstat:

 sys/kern/subr_tftproot.c |  14 +++++++-------
 1 files changed, 7 insertions(+), 7 deletions(-)

diffs (40 lines):

diff -r 4ee711a0b1c4 -r 3677e83640f6 sys/kern/subr_tftproot.c
--- a/sys/kern/subr_tftproot.c  Mon Oct 31 15:08:45 2016 +0000
+++ b/sys/kern/subr_tftproot.c  Mon Oct 31 15:27:24 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: subr_tftproot.c,v 1.18 2016/06/10 13:27:15 ozaki-r Exp $ */
+/*     $NetBSD: subr_tftproot.c,v 1.19 2016/10/31 15:27:24 maxv Exp $ */
 
 /*-
  * Copyright (c) 2007 Emmanuel Dreyfus, all rights reserved.
@@ -39,7 +39,7 @@
 #include "opt_md.h"
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_tftproot.c,v 1.18 2016/06/10 13:27:15 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_tftproot.c,v 1.19 2016/10/31 15:27:24 maxv Exp $");
 
 #include <sys/param.h>
 #include <sys/types.h>
@@ -316,16 +316,16 @@
        printf("\n");
 
        /*
-        * Ack the last block. so_send frees m_outbuf, therefore
-        * we do not want to free it ourselves.
-        * Ignore errors, as we already have the whole file.
+        * Ack the last block. Ignore errors, as we already have the whole
+        * file.
         */
        if ((error = (*so->so_send)(so, mtod(m_serv, struct sockaddr *), NULL,
            m_outbuf, NULL, 0, l)) != 0)
                DPRINTF(("%s():%d tftproot: sosend returned %d\n", 
                    __func__, __LINE__, error));
-       else
-               m_outbuf = NULL;
+
+       /* Freed by the protocol */
+       m_outbuf = NULL;
 
        /* 
         * And use it as the root ramdisk.