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 82FF3C4321E for ; Fri, 1 Apr 2022 15:37:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349425AbiDAPcz (ORCPT ); Fri, 1 Apr 2022 11:32:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55844 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349955AbiDAO61 (ORCPT ); Fri, 1 Apr 2022 10:58:27 -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 7E1A8170DB1; Fri, 1 Apr 2022 07:45:35 -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 20D60B8240E; Fri, 1 Apr 2022 14:45:35 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E53E9C3410F; Fri, 1 Apr 2022 14:45:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1648824333; bh=ie3ERVJUGrppjLIYAsm6LgtD05Un/FhSK3Ao2Boc3ho=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aSrx1JGNKm0Ia8LS9Dw9ozpSQlLIzWTfHP87LlM2QReH+yMfVYrEQHTGDPwdFCLtR qOZ1hcjxaUcgE8Uh5Iz+I6vcPXGY5C3oCnSCv9G1oCFtv2kRFmdRtYgKSYgCRzwGna o9qp6QmFm7RajwZgsu4f5a6iLLvKOcXaEKB/km/iYP7eZil1dZt67yVfNIHrktqPW3 DcqiFttO43e/5a6jR5x7+xhtAXcnCf5IkZ7R9eeqqrchHK+jAAp02CZgAznyU8zAHL RlxUuv/udiQMAjQfJFIkorYiVOeuNc1FcCoS7eHnVKGilXr/054u64+hiZdqE/NeW9 qVJVmmyBAc7BQ== 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 5.4 19/37] dm ioctl: prevent potential spectre v1 gadget Date: Fri, 1 Apr 2022 10:44:28 -0400 Message-Id: <20220401144446.1954694-19-sashal@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220401144446.1954694-1-sashal@kernel.org> References: <20220401144446.1954694-1-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 3f15d8dc2b71..7a73f2fa0ad7 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -17,6 +17,7 @@ #include #include #include +#include #include @@ -1696,6 +1697,7 @@ 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