From nobody Tue Jun 23 01:18:08 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 2221AC35273 for ; Mon, 14 Mar 2022 12:34:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238487AbiCNMf1 (ORCPT ); Mon, 14 Mar 2022 08:35:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42654 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245425AbiCNMc7 (ORCPT ); Mon, 14 Mar 2022 08:32:59 -0400 Received: from mail-pf1-x42b.google.com (mail-pf1-x42b.google.com [IPv6:2607:f8b0:4864:20::42b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 355D22BDB for ; Mon, 14 Mar 2022 05:29:47 -0700 (PDT) Received: by mail-pf1-x42b.google.com with SMTP id s42so14240651pfg.0 for ; Mon, 14 Mar 2022 05:29:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id; bh=+61bL8B55NzgOqf7v3x/0YUtZZbl/U3fuc66QbGFfZE=; b=kvbcNPZ8AU8hjjuMqdRRJzfMRv9vW8WHAUkY0BVtWGuE3kTb2M4e2gubEeWWT3UWNM ub1mHQaSYRCvHmV3w6vPMALxasxRXBwnlkMu0mtMA/6ATHNOhXl3fUf/zEHhELFD4gS3 NPxGMJs4sTMyyzyc7F7hI8WXN65iCmKowwK80REtHveYu/PMyu0qbIyC6pk5GXx4OC05 Pdo04W7EK1ip99+LHKQTb0BVPCB8WRnNgC85WGyhoFcT8wREdfnjmSBNMiGLdB2fCNtw swRVXL/zeFAoU1HWhyIkVructY4qmGlbFQPr2lA4uR/hy9u9dYY+Ryl8iuqsuuRtAZFb KJfw== 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=+61bL8B55NzgOqf7v3x/0YUtZZbl/U3fuc66QbGFfZE=; b=Y+2qKnMHCAttpBj1iI34AkWQF3f6z6y2auzfpD6ujeN8xVq5LFw8Mm8iu/MSQOWx6j BMVnLKCSpXyNzM9HL/d09RGWGkiUiKsxADo7//nxZGeTx3f97U/1yXX/4B104K4dt3av FEOqPrsifylW/BjwqjmDYu0x24H5NRgR2CI/8KhzkKhG0XqPVXdF8aZ6KEQUhkGCW3N5 j26WX0SDPk2axFmh+vczm76NGL2XTLkOBW7WNW/08swRECT4Hcxfmjg2cTqFMe7krpiN gfAoNhzDWyt2N1wB2Azm22AHtKNnD8/Ib5upO4FWGiIMigJUyKdMlAtzI9z//fUhxBqO smmw== X-Gm-Message-State: AOAM53036IIayflzuyZizNkUTngfVUrIo5sPgxWrJZDgnS1NOjplRRlL k9Si/Djpn4LWz8PTiyhCFcb2eeIubEWQDw== X-Google-Smtp-Source: ABdhPJzvp/C8q1A8LG8IwnlOs9l/uNHFJyL0CoGXtylHk+itAljLyE1slZmcSiRQaO8klIv83082Ng== X-Received: by 2002:a65:41cc:0:b0:380:6f53:a550 with SMTP id b12-20020a6541cc000000b003806f53a550mr19757301pgq.471.1647260986752; Mon, 14 Mar 2022 05:29:46 -0700 (PDT) Received: from ubuntu.huawei.com ([119.3.119.19]) by smtp.googlemail.com with ESMTPSA id 8-20020a056a00070800b004e14ae3e8d7sm20552263pfl.164.2022.03.14.05.29.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 14 Mar 2022 05:29:46 -0700 (PDT) From: Xiaomeng Tong To: gregkh@linuxfoundation.org, jirislaby@kernel.org Cc: linux-kernel@vger.kernel.org, Xiaomeng Tong Subject: [RESEND PATCH v2] vt_ioctl: fix potential spectre v1 in VT_DISALLOCATE Date: Mon, 14 Mar 2022 20:29:21 +0800 Message-Id: <20220314122921.31223-1-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. Reviewed-by: Jiri Slaby Signed-off-by: Xiaomeng Tong --- v1 -> v2: - Add Reviewed-by https://lore.kernel.org/lkml/20220222081101.21233-1-xiam0nd.tong@gmail.com/ RFC -> v1: - Adjust code style [Jiri Slaby] https://lore.kernel.org/lkml/20220222073954.20212-1-xiam0nd.tong@gmail.com/ RFC: https://lore.kernel.org/lkml/20220222035648.17984-1-xiam0nd.tong@gmail.com/ --- 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