Prevent ioctl(WSKBDIO_GETENCODINGS) NULL deference when sysctl

machdep.forceukbd is enabled without any USB keyboard being attached.

Found the hard way by sthen@; ok miod@

diff --git a/sys/dev/wscons/wskbd.c b/sys/dev/wscons/wskbd.c
index 7631cd5..f551bf5 100644 (file)
--- a/sys/dev/wscons/wskbd.c
+++ b/sys/dev/wscons/wskbd.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: wskbd.c,v 1.117 2023/11/23 15:02:57 deraadt Exp $ */
+/* $OpenBSD: wskbd.c,v 1.118 2024/02/18 20:17:48 anton Exp $ */
 /* $NetBSD: wskbd.c,v 1.80 2005/05/04 01:52:16 augustss Exp $ */
 
 /*
@@ -1229,8 +1229,11 @@ getkeyrepeat:
 
        case WSKBDIO_GETENCODINGS:
                uedp = (struct wskbd_encoding_data *)data;
-               for (count = 0; sc->id->t_keymap.keydesc[count].name; count++)
-                       ;
+               count = 0;
+               if (sc->id->t_keymap.keydesc != NULL) {
+                       while (sc->id->t_keymap.keydesc[count].name)
+                               count++;
+               }
                if (uedp->nencodings > count)
                        uedp->nencodings = count;
                for (i = 0; i < uedp->nencodings; i++) {