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 3193AC38A05 for ; Fri, 1 Apr 2022 15:40:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1357061AbiDAPiJ (ORCPT ); Fri, 1 Apr 2022 11:38:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52358 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350564AbiDAPAJ (ORCPT ); Fri, 1 Apr 2022 11:00:09 -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 D9CB3185441; Fri, 1 Apr 2022 07:48:01 -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 89BD2B824D5; Fri, 1 Apr 2022 14:48:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 589B1C34111; Fri, 1 Apr 2022 14:47:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1648824479; bh=nPE0/rhmVHxbpJ45v6/d7l7g5cDcyD9IGl2HGzZV6dg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=A73qRg5PRhIIgRK9ubyvZCiluLopM4rk8VW5JFYFG1EypEZ0DB0WE6cX05U9115qu XgC9Gks63QMwvL1VFAtSD4Nkt6XjZD7F0Zhxwds+6I0rGfgAIBXhdTWbT0XBDynghH ojRlnJctFKSEa7JIwY5D3jIQTrHjM426uys/bwWG+GEex+ROtuYLzkUSGFNlg95Ps7 n97UeFXcjg0UfQ66T3WSqzTCBdXYrCiWHcg7MW/q9AHnjDwH51sPrMiQvZRgDfPoQX KtR8B6Sy0DFZ0R5oeAr2zO1E7YAlw8IiBnp7gwkUgHkZ8sNMg/cPUzaxhVEycJgggX kF/IcuRtrEHMA== 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 4.14 10/22] dm ioctl: prevent potential spectre v1 gadget Date: Fri, 1 Apr 2022 10:47:17 -0400 Message-Id: <20220401144729.1955554-10-sashal@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220401144729.1955554-1-sashal@kernel.org> References: <20220401144729.1955554-1-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 2f020401d5ba..ddfea5324b58 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -17,6 +17,7 @@ #include #include #include +#include #include @@ -1669,6 +1670,7 @@ 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