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 7D816EEB560 for ; Fri, 8 Sep 2023 18:31:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244963AbjIHSbn (ORCPT ); Fri, 8 Sep 2023 14:31:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58172 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344447AbjIHSbV (ORCPT ); Fri, 8 Sep 2023 14:31:21 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 955D82125; Fri, 8 Sep 2023 11:22:16 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1288BC433BF; Fri, 8 Sep 2023 18:20:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1694197257; bh=0+YyDjwx3h8JedkPqH2eJ8aZFt0cO7/GGWjCLDYPi8Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=c0m0CGZwYlBchrAUBxeNh60fw6f03iq+z/O+VtmRnsqDzdJYfNPir4vxpzV6802aG 0QC2r8tARvt90ZOvev0UurwvrGogsdxltkrJs9T6fW2rZhKlwcIZ+8WhK1I6wrmu5A gjiCHK6cmVJ+1NQ4F7m7xilIznZuL1hBhM8Yn+b9uU3wStQGH3n/PfxvgvrpvLMiqX +XOqaT5D7dkJY306lOYMePxX1Wc2MJWTHVnW9Np0GUrDwa2wDwhndx2hQJPKc0IYQY rCmN7MEhejNT4q9sfFsma/ez4bytejHqS4uBb4aLSSNEMEI9OxWRWZ3iAHKA+6GCam RUVrFeXAGGmRw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Mark O'Donovan , Herbert Xu , Sasha Levin , zohar@linux.ibm.com Subject: [PATCH AUTOSEL 5.4 04/10] crypto: lib/mpi - avoid null pointer deref in mpi_cmp_ui() Date: Fri, 8 Sep 2023 14:20:38 -0400 Message-Id: <20230908182046.3460968-4-sashal@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230908182046.3460968-1-sashal@kernel.org> References: <20230908182046.3460968-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.4.256 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mark O'Donovan [ Upstream commit 9e47a758b70167c9301d2b44d2569f86c7796f2d ] During NVMeTCP Authentication a controller can trigger a kernel oops by specifying the 8192 bit Diffie Hellman group and passing a correctly sized, but zeroed Diffie Hellamn value. mpi_cmp_ui() was detecting this if the second parameter was 0, but 1 is passed from dh_is_pubkey_valid(). This causes the null pointer u->d to be dereferenced towards the end of mpi_cmp_ui() Signed-off-by: Mark O'Donovan Signed-off-by: Herbert Xu Signed-off-by: Sasha Levin --- lib/mpi/mpi-cmp.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/lib/mpi/mpi-cmp.c b/lib/mpi/mpi-cmp.c index d25e9e96c310f..ceaebe181cd70 100644 --- a/lib/mpi/mpi-cmp.c +++ b/lib/mpi/mpi-cmp.c @@ -25,8 +25,12 @@ int mpi_cmp_ui(MPI u, unsigned long v) mpi_limb_t limb = v; mpi_normalize(u); - if (!u->nlimbs && !limb) - return 0; + if (u->nlimbs == 0) { + if (v == 0) + return 0; + else + return -1; + } if (u->sign) return -1; if (u->nlimbs > 1) -- 2.40.1