[src/trunk]: src/sys/dev/mii Do not deref a NULL pointer if no current media ...

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

details:   https://anonhg.NetBSD.org/src/rev/01afad70e834
branches:  trunk
changeset: 826048:01afad70e834
user:      martin <martin%NetBSD.org@localhost>
date:      Sat Aug 12 11:21:15 2017 +0000

description:
Do not deref a NULL pointer if no current media has been selected.
This error condition does not happen with properly working hardware, but it is
no good reason for a kernel panic either.

diffstat:

 sys/dev/mii/nsphy.c |  10 +++++-----
 1 files changed, 5 insertions(+), 5 deletions(-)

diffs (45 lines):

diff -r 07c0154b9ff6 -r 01afad70e834 sys/dev/mii/nsphy.c
--- a/sys/dev/mii/nsphy.c       Sat Aug 12 11:03:47 2017 +0000
+++ b/sys/dev/mii/nsphy.c       Sat Aug 12 11:21:15 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: nsphy.c,v 1.60 2016/07/07 06:55:41 msaitoh Exp $       */
+/*     $NetBSD: nsphy.c,v 1.61 2017/08/12 11:21:15 martin Exp $        */
 
 /*-
  * Copyright (c) 1998, 1999, 2000 The NetBSD Foundation, Inc.
@@ -60,7 +60,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: nsphy.c,v 1.60 2016/07/07 06:55:41 msaitoh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: nsphy.c,v 1.61 2017/08/12 11:21:15 martin Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -153,7 +153,7 @@
                /*
                 * If we're not polling our PHY instance, just return.
                 */
-               if (IFM_INST(ife->ifm_media) != sc->mii_inst)
+               if (ife != NULL && IFM_INST(ife->ifm_media) != sc->mii_inst)
                        return (0);
                break;
 
@@ -162,7 +162,7 @@
                 * If the media indicates a different PHY instance,
                 * isolate ourselves.
                 */
-               if (IFM_INST(ife->ifm_media) != sc->mii_inst) {
+               if (ife != NULL && IFM_INST(ife->ifm_media) != sc->mii_inst) {
                        reg = PHY_READ(sc, MII_BMCR);
                        PHY_WRITE(sc, MII_BMCR, reg | BMCR_ISO);
                        return (0);
@@ -216,7 +216,7 @@
                /*
                 * If we're not currently selected, just return.
                 */
-               if (IFM_INST(ife->ifm_media) != sc->mii_inst)
+               if (ife != NULL && IFM_INST(ife->ifm_media) != sc->mii_inst)
                        return (0);
 
                if (mii_phy_tick(sc) == EJUSTRETURN)