From: anton <anton@openbsd.org>
Date: Sun, 18 Feb 2024 20:17:48 +0000 (+0000)
Subject: Prevent ioctl(WSKBDIO_GETENCODINGS) NULL deference when sysctl
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=508919f1adb8eb51d424cf37ddfc71cb1ca34729;p=openbsd

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 7631cd5f701..f551bf5b892 100644
--- 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++) {