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 203C9C47080 for ; Fri, 1 Apr 2022 15:13:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354528AbiDAPMD (ORCPT ); Fri, 1 Apr 2022 11:12:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60688 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352069AbiDAOtu (ORCPT ); Fri, 1 Apr 2022 10:49:50 -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 591B32B123E; Fri, 1 Apr 2022 07:40:58 -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 ACE75B82518; Fri, 1 Apr 2022 14:40:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 804C8C34114; Fri, 1 Apr 2022 14:40:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1648824009; bh=9/9iLykxpxjIxqulCf4eS0Gth61utHyAlCQBiVJTpdE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=g5DLHXs6MD8x/qSZgBmFR1bm4oTdrMWyoahjDq7gEAaAjgosCfS8nJ5Y4lCtZjWqb U4EuN59E8/Fhxl9A4AqQRhWuSxYcprS2ie0CE2k4PXkWbQcE8hmVziIatJZJqVeO7x EC/kMLNa7tNFGVBrxl7AkBlIPdVEQP9mxHUTnIAH4bfLmWO7s3/SOHShgAs6j4olKT xBz7K/GmsWp/3gccgZ6Wc6lb5y/9ntpdlvQ0KzawLcCNFDhPVeXZoTSGwNxaIWnDKh 7LVUQVoTlWkx14CW0k0/y/K7aE86oXebIDOQFae4LZoUBGAr80SpR/6uEvHfKTFKT8 w3VvTTrb+OrlA== 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 5.15 49/98] dm ioctl: prevent potential spectre v1 gadget Date: Fri, 1 Apr 2022 10:36:53 -0400 Message-Id: <20220401143742.1952163-49-sashal@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220401143742.1952163-1-sashal@kernel.org> References: <20220401143742.1952163-1-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 21fe8652b095..901abd6dea41 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -18,6 +18,7 @@ #include #include #include +#include #include #include @@ -1788,6 +1789,7 @@ 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