From mboxrd@z Thu Jan 1 00:00:00 1970 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 A1E87C352AA for ; Fri, 1 Apr 2022 15:40:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1357602AbiDAPir (ORCPT ); Fri, 1 Apr 2022 11:38:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33066 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350676AbiDAPAZ (ORCPT ); Fri, 1 Apr 2022 11:00:25 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 383D239140; Fri, 1 Apr 2022 07:48:48 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id DF2D4B82500; Fri, 1 Apr 2022 14:48:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 68BC9C340F2; Fri, 1 Apr 2022 14:48:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1648824525; bh=NrhotgYaEmvmytZ5SsnIyI+yW0k65GrkEjY84+HFvTI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZB/zK2amGa9yqIXvO6ehMNAfVoIojcmYhyGWc0Vy53xWPuTQfxO3bygpV8SPy6PYx gifKrcQgYa9R4ov00CpCdH0/ouLO5Peeb1ZU+ktgdEP4QPaFNxDlk0KiihEKAjtjKn GX0+4W6rJk3mX+5jy/2QWJzvJfpDwid8cCxxhy3Id3yPo969n7nwHNR0owMc43mOB0 AMvI7fQEyXn4WcT7hXujyK5k9JFRIIKOGNB3C92RQYqhZDEb9skKRIb+4LnAAEVlvG q7WX6CxOu4dFTSIYDEI8IVIAVJ5/gn97WrHHDPAL8KAxYGLMPbKxbfH5Z/DHi4a/g9 FIzKjEExEeIxQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jordy Zomer , Jordy Zomer , Mike Snitzer , Sasha Levin , agk@redhat.com, snitzer@kernel.org, dm-devel@redhat.com Subject: [PATCH AUTOSEL 4.9 07/16] dm ioctl: prevent potential spectre v1 gadget Date: Fri, 1 Apr 2022 10:48:18 -0400 Message-Id: <20220401144827.1955845-7-sashal@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220401144827.1955845-1-sashal@kernel.org> References: <20220401144827.1955845-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jordy Zomer [ Upstream commit cd9c88da171a62c4b0f1c70e50c75845969fbc18 ] It appears like cmd could be a Spectre v1 gadget as it's supplied by a user and used as an array index. Prevent the contents of kernel memory from being leaked to userspace via speculative execution by using array_index_nospec. Signed-off-by: Jordy Zomer Signed-off-by: Mike Snitzer Signed-off-by: Sasha Levin --- drivers/md/dm-ioctl.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c index eb2659a12310..70245782e7f6 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -16,6 +16,7 @@ #include #include #include +#include #include @@ -1642,6 +1643,7 @@ static ioctl_fn lookup_ioctl(unsigned int cmd, int *ioctl_flags) if (unlikely(cmd >= ARRAY_SIZE(_ioctls))) return NULL; + cmd = array_index_nospec(cmd, ARRAY_SIZE(_ioctls)); *ioctl_flags = _ioctls[cmd].flags; return _ioctls[cmd].fn; } -- 2.34.1