From nobody Thu Jun 25 09:39:14 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E5A01C433EF for ; Tue, 22 Feb 2022 07:40:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229699AbiBVHkc (ORCPT ); Tue, 22 Feb 2022 02:40:32 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36136 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229452AbiBVHka (ORCPT ); Tue, 22 Feb 2022 02:40:30 -0500 Received: from mail-pf1-x432.google.com (mail-pf1-x432.google.com [IPv6:2607:f8b0:4864:20::432]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5168E125CA3 for ; Mon, 21 Feb 2022 23:40:06 -0800 (PST) Received: by mail-pf1-x432.google.com with SMTP id z15so5379163pfe.7 for ; Mon, 21 Feb 2022 23:40:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id; bh=NjlSIvkhTVirW9AjcVgK/bv/kP1TeZNvmGeoPnvDvqU=; b=ofmhMbr92zX+t9ys9oSMqbuaURU/LN5aS0R7G8Fau6OATgdwtRcVds3ix83KQGSXmN EWuw4uwYnIKFJPpsd5W3S3NpIlKFs+YVHXlXFhedKqay9xtiedhH9bD1oQlGCjSI+atY bfogCYxMQSZe2oUlYtC5j8XBQdrukCZdzopc8b6glF1y4v0AS2HhtGxka4L+jzdrl2d8 ClM1c/7NuaXtoII4vHx7XSeXG5zPOW9vcr++GsN4HVXx90toIuA0MB0cQaLOYR0t9D94 ZvEn+qIQfIXaBZLtKz21NKPmZ0sDeP3yruezvXWbhpu5gv5CyJJiAPUPPulWZnt8CnMH lNBQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=NjlSIvkhTVirW9AjcVgK/bv/kP1TeZNvmGeoPnvDvqU=; b=F7maTPcBjeOgaEH+qCWiemZICQ2Oo6enUSq5m6WQRbr41tDJq5al163RMgoZJrJFWJ TCjNDGSrW8T4ft55D0jZalKpCotxtGd9yvEEFLOITwbM87ZrTZb7KIJI415Gnu2ZL5Yc 4IfStnhRnLEzQrQjlpj+wLe74YDIu4JVF48ZPXa/313ApgNBxQW3DCxXjhMYvC+v01GM cPn4tTGitliB+B3QVD7z+9Ctgzg3ljipTYPDkMUEiDhYUXX2mzUO8V5kXy447sprh3Eu xA4Ewink0iPs3Qbm5CpEapD8BQh2RxKc3FMaUAIEhyZfyWAq1bwVdCJW4BCHiEXLcYaG mf3g== X-Gm-Message-State: AOAM531sGq8zafDtRqt+fcTIcrn+1VUB76O5N20qkdV9zZfW2MIfbHXe mWEQiiXVFAWgZqaYRENbYXA= X-Google-Smtp-Source: ABdhPJxoTcUTBDauTM4MFsu+I1xV6Z81CHLb149pntUgDpj3gFmUQHRwGwlYdff+JKX2jnYcUXGoRQ== X-Received: by 2002:a63:2bc1:0:b0:35e:c54b:3be0 with SMTP id r184-20020a632bc1000000b0035ec54b3be0mr18820358pgr.105.1645515605832; Mon, 21 Feb 2022 23:40:05 -0800 (PST) Received: from ubuntu.huawei.com ([119.3.119.21]) by smtp.googlemail.com with ESMTPSA id x2sm1635827pje.24.2022.02.21.23.40.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 21 Feb 2022 23:40:05 -0800 (PST) From: Xiaomeng Tong To: gregkh@linuxfoundation.org, jirislaby@kernel.org Cc: linux-kernel@vger.kernel.org, Xiaomeng Tong Subject: [PATCH v1] vt_ioctl: fix potential spectre v1 in VT_DISALLOCATE Date: Tue, 22 Feb 2022 15:39:54 +0800 Message-Id: <20220222073954.20212-1-xiam0nd.tong@gmail.com> X-Mailer: git-send-email 2.17.1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" In VT_ACTIVATE an almost identical code path has been patched with array_index_nospec. In the VT_DISALLOCATE path, the arg is the user input from a system call argument and lately used as a index for vc_cons[index].d access, which can be reached through path like vt_disallocate->vc_busy or vt_disallocate->vc_deallocate. For consistency both code paths should have the same mitigations applied. Also, the code style is adjusted as suggested by Jiri. Signed-off-by: Xiaomeng Tong Reviewed-by: Jiri Slaby --- drivers/tty/vt/vt_ioctl.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/tty/vt/vt_ioctl.c b/drivers/tty/vt/vt_ioctl.c index 580136986..8c685b501 100644 --- a/drivers/tty/vt/vt_ioctl.c +++ b/drivers/tty/vt/vt_ioctl.c @@ -898,11 +898,13 @@ int vt_ioctl(struct tty_struct *tty, if (arg > MAX_NR_CONSOLES) return -ENXIO; =20 - if (arg =3D=3D 0) + if (arg =3D=3D 0) { vt_disallocate_all(); - else - return vt_disallocate(--arg); - break; + break; + } + + arg =3D array_index_nospec(arg - 1, MAX_NR_CONSOLES); + return vt_disallocate(arg); =20 case VT_RESIZE: { --=20 2.17.1