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 18D70C25B4E for ; Tue, 24 Jan 2023 13:45:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234472AbjAXNpK (ORCPT ); Tue, 24 Jan 2023 08:45:10 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35566 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234270AbjAXNoq (ORCPT ); Tue, 24 Jan 2023 08:44:46 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5CA7D46173; Tue, 24 Jan 2023 05:43:30 -0800 (PST) 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 dfw.source.kernel.org (Postfix) with ESMTPS id E14DF611FC; Tue, 24 Jan 2023 13:42:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1EDD6C433D2; Tue, 24 Jan 2023 13:42:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1674567775; bh=Yp3hHNij9/bTJKTCgLv3LCBfq/9uGno3R7DONhwxznk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mP6OAcPtQYai7TUowVOOdU0UcBxPyEkWXpEoM4qgl5NT//72VD4Z2b8sbsuId4DoY W3uTdEklYcj4WcF7j3ljU+NJoqfwroqvT/qfa0J9TE3EmdalxCnSzf+OL1dFvfeLqj EQeVsv1CgRWygBiIsiRemhNAsxiRhL5WVzkP2l0K11DrME45g8pDbmkFc0VZ5MWSHG VOsrzgyMW2p0hLOJE/KWMQxz+3ZBxnnKQRdXNmRLmDQICHQRQS4q0grmC9c7Hajpqg GbzDRqUni81sT6NMiWDubql0CGP4W0rtW94nkYeYNn6NDKZ3J8T+Kc/xSrYFXSux9s D25ubjEkSaZhQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , Jordy Zomer , Linus Torvalds , Sasha Levin , ebiederm@xmission.com, brho@google.com, catalin.marinas@arm.com, broonie@kernel.org, legion@kernel.org, Jason@zx2c4.com, surenb@google.com Subject: [PATCH AUTOSEL 6.1 34/35] prlimit: do_prlimit needs to have a speculation check Date: Tue, 24 Jan 2023 08:41:30 -0500 Message-Id: <20230124134131.637036-34-sashal@kernel.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230124134131.637036-1-sashal@kernel.org> References: <20230124134131.637036-1-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: Greg Kroah-Hartman [ Upstream commit 739790605705ddcf18f21782b9c99ad7d53a8c11 ] do_prlimit() adds the user-controlled resource value to a pointer that will subsequently be dereferenced. In order to help prevent this codepath from being used as a spectre "gadget" a barrier needs to be added after checking the range. Reported-by: Jordy Zomer Tested-by: Jordy Zomer Suggested-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- kernel/sys.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/sys.c b/kernel/sys.c index 5fd54bf0e886..88b31f096fb2 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1442,6 +1442,8 @@ static int do_prlimit(struct task_struct *tsk, unsigned int resource, if (resource >= RLIM_NLIMITS) return -EINVAL; + resource = array_index_nospec(resource, RLIM_NLIMITS); + if (new_rlim) { if (new_rlim->rlim_cur > new_rlim->rlim_max) return -EINVAL; -- 2.39.0