[src/trunk]: src/sys/net fix leak when encap_attach() fails twice.

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

details:   https://anonhg.NetBSD.org/src/rev/aa787967382c
branches:  trunk
changeset: 825947:aa787967382c
user:      knakahara <knakahara%NetBSD.org@localhost>
date:      Tue Aug 08 03:14:50 2017 +0000

description:
fix leak when encap_attach() fails twice.

XXX need pullup to -8 branch

diffstat:

 sys/net/if_gif.c |  47 +++++++++++++++++++++++++----------------------
 1 files changed, 25 insertions(+), 22 deletions(-)

diffs (73 lines):

diff -r bf19923054b4 -r aa787967382c sys/net/if_gif.c
--- a/sys/net/if_gif.c  Tue Aug 08 02:27:03 2017 +0000
+++ b/sys/net/if_gif.c  Tue Aug 08 03:14:50 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_gif.c,v 1.127 2017/06/22 09:26:43 knakahara Exp $   */
+/*     $NetBSD: if_gif.c,v 1.128 2017/08/08 03:14:50 knakahara Exp $   */
 /*     $KAME: if_gif.c,v 1.76 2001/08/20 02:01:02 kjc Exp $    */
 
 /*
@@ -31,7 +31,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_gif.c,v 1.127 2017/06/22 09:26:43 knakahara Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_gif.c,v 1.128 2017/08/08 03:14:50 knakahara Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_inet.h"
@@ -997,31 +997,34 @@
 
        /*
         * Secondly, try to set new configurations.
-        * If the setup failed, rollback to old configurations.
         */
-       do {
-               osrc = sc->gif_psrc;
-               odst = sc->gif_pdst;
-               sc->gif_psrc = nsrc;
-               sc->gif_pdst = ndst;
-
+       osrc = sc->gif_psrc;
+       odst = sc->gif_pdst;
+       sc->gif_psrc = nsrc;
+       sc->gif_pdst = ndst;
+       error = gif_encap_attach(sc);
+       if (error && osrc != NULL && odst != NULL) {
+               /*
+                * Thirdly, when error occured, rollback to old configurations,
+                * if last setting is valid.
+                */
+               sc->gif_psrc = osrc;
+               sc->gif_pdst = odst;
+               osrc = nsrc; /* to free */
+               odst = ndst; /* to free */
                error = gif_encap_attach(sc);
-               if (error) {
-                       /* rollback to the last configuration. */
-                       nsrc = osrc;
-                       ndst = odst;
-                       osrc = sc->gif_psrc;
-                       odst = sc->gif_pdst;
-
-                       continue;
-               }
-       } while (error != 0 && (nsrc != NULL && ndst != NULL));
-       /* Thirdly, even rollback failed, clear configurations. */
+       }
        if (error) {
-               osrc = sc->gif_psrc;
-               odst = sc->gif_pdst;
+               /*
+                * Fourthly, even rollback failed or last setting is not valid,
+                * clear configurations.
+                */
+               osrc = sc->gif_psrc; /* to free */
+               odst = sc->gif_pdst; /* to free */
                sc->gif_psrc = NULL;
                sc->gif_pdst = NULL;
+               sockaddr_free(nsrc);
+               sockaddr_free(ndst);
        }
 
        if (osrc)