From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751808AbdITVid (ORCPT ); Wed, 20 Sep 2017 17:38:33 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:41136 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751753AbdITVic (ORCPT ); Wed, 20 Sep 2017 17:38:32 -0400 From: Colin King To: Greg Kroah-Hartman , Jiri Slaby , Ingo Molnar Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] tty: vt: keyboard: add range check to kbs->kb_func index Date: Wed, 20 Sep 2017 22:38:28 +0100 Message-Id: <20170920213828.5563-1-colin.king@canonical.com> X-Mailer: git-send-email 2.14.1 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Colin Ian King A value outside the range 0..MAX_NR_FUNC-1 in kbs->kb_func will cause an array bounds overflow on func_table. Fix this by adding a range check. Detected by CoverityScan, CID#401961 ("Untrusted array index read") Fixes: 079c9534a96d ("vt:tackle kbd_table") Signed-off-by: Colin Ian King --- drivers/tty/vt/keyboard.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/tty/vt/keyboard.c b/drivers/tty/vt/keyboard.c index f4166263bb3a..1ecf545a96a8 100644 --- a/drivers/tty/vt/keyboard.c +++ b/drivers/tty/vt/keyboard.c @@ -1982,6 +1982,11 @@ int vt_do_kdgkb_ioctl(int cmd, struct kbsentry __user *user_kdgkb, int perm) kbs->kb_string[sizeof(kbs->kb_string)-1] = '\0'; i = kbs->kb_func; + if (i < 0 || i >= MAX_NR_FUNC) { + ret = -EINVAL; + goto reterr; + } + switch (cmd) { case KDGKBSENT: sz = sizeof(kbs->kb_string) - 1; /* sz should have been -- 2.14.1