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 7F1CEC25B4E for ; Sun, 22 Jan 2023 15:06:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229917AbjAVPG6 (ORCPT ); Sun, 22 Jan 2023 10:06:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60834 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229990AbjAVPG5 (ORCPT ); Sun, 22 Jan 2023 10:06:57 -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 885751E1C6 for ; Sun, 22 Jan 2023 07:06:52 -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 24FBC60C59 for ; Sun, 22 Jan 2023 15:06:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 393C1C433D2; Sun, 22 Jan 2023 15:06:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1674400011; bh=bUmI9+Y6UTIoszobnSkRjDlTI95vA/LfTmBQlFUeabs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HeSUM9Ixy5YaF6l2yhur96B/h4mIkPhPW3f8i1AqlBpdneOkJ4F82LVw2OwxewLRt tH0/EHff0jY3KQhQ5ejmJJB+vaEdGLlaZ3OSepQI467JYuJX6d2lBUk3vQgHZ9JDqK ybGKjJfjUDWFYJG3N9Awq8sSPAp5O8GZfmuhZzqA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jordy Zomer , Linus Torvalds Subject: [PATCH 4.14 08/25] prlimit: do_prlimit needs to have a speculation check Date: Sun, 22 Jan 2023 16:04:08 +0100 Message-Id: <20230122150218.150123151@linuxfoundation.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230122150217.788215473@linuxfoundation.org> References: <20230122150217.788215473@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Greg Kroah-Hartman commit 739790605705ddcf18f21782b9c99ad7d53a8c11 upstream. 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 --- kernel/sys.c | 2 ++ 1 file changed, 2 insertions(+) --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1472,6 +1472,8 @@ int do_prlimit(struct task_struct *tsk, 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;