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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D1DBDC606BD for ; Mon, 8 Jul 2019 15:18:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AA3E0216E3 for ; Mon, 8 Jul 2019 15:18:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562599085; bh=XP/wjr61UkwKqFacjGA1z8OfOfSKKAteAPObbnI2bmo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=PvUu+ZY5fsd5VcNWfANUhLrQkHvKoKNdB8j1epVHQL8Z4j+uISbZDbD8GeXAwGbaU XE7C7/YjwoTFUNiW/6EAWeoeuZrQKk4JbjQQO9J4l8MCoWBvreqgPJiIPQDTLes3Ih dqbuTrRoq63g/+ctUjWcNGlXaIyayzfwtXYLh2Xc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732924AbfGHPR6 (ORCPT ); Mon, 8 Jul 2019 11:17:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:41382 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732895AbfGHPRu (ORCPT ); Mon, 8 Jul 2019 11:17:50 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E5446216E3; Mon, 8 Jul 2019 15:17:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562599070; bh=XP/wjr61UkwKqFacjGA1z8OfOfSKKAteAPObbnI2bmo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lcqHqrws4HO19Zd4iG9Bu+/w4aMV0GQwqNSmwSuMbpSm1VcIj4DILHWUkXJmogsvV IEQz+NNDsTTSS4R2KYRswNqDpt7EZpqqG5D4/upGP9wXFdIP3tJ5Vy2DGFDuYpf3PA 7n36KOoo8TwN85WzZtERYoBBLSFoiPBMvYgk2f6A= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+f7baccc38dcc1e094e77@syzkaller.appspotmail.com, Herbert Xu , Eric Biggers Subject: [PATCH 4.4 67/73] lib/mpi: Fix karactx leak in mpi_powm Date: Mon, 8 Jul 2019 17:13:17 +0200 Message-Id: <20190708150524.807209089@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190708150513.136580595@linuxfoundation.org> References: <20190708150513.136580595@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Herbert Xu commit c8ea9fce2baf7b643384f36f29e4194fa40d33a6 upstream. Sometimes mpi_powm will leak karactx because a memory allocation failure causes a bail-out that skips the freeing of karactx. This patch moves the freeing of karactx to the end of the function like everything else so that it can't be skipped. Reported-by: syzbot+f7baccc38dcc1e094e77@syzkaller.appspotmail.com Fixes: cdec9cb5167a ("crypto: GnuPG based MPI lib - source files...") Cc: Signed-off-by: Herbert Xu Reviewed-by: Eric Biggers Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman --- lib/mpi/mpi-pow.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) --- a/lib/mpi/mpi-pow.c +++ b/lib/mpi/mpi-pow.c @@ -37,6 +37,7 @@ int mpi_powm(MPI res, MPI base, MPI exp, MPI mod) { mpi_ptr_t mp_marker = NULL, bp_marker = NULL, ep_marker = NULL; + struct karatsuba_ctx karactx = {}; mpi_ptr_t xp_marker = NULL; mpi_ptr_t tspace = NULL; mpi_ptr_t rp, ep, mp, bp; @@ -164,13 +165,11 @@ int mpi_powm(MPI res, MPI base, MPI exp, int c; mpi_limb_t e; mpi_limb_t carry_limb; - struct karatsuba_ctx karactx; xp = xp_marker = mpi_alloc_limb_space(2 * (msize + 1)); if (!xp) goto enomem; - memset(&karactx, 0, sizeof karactx); negative_result = (ep[0] & 1) && base->sign; i = esize - 1; @@ -295,8 +294,6 @@ int mpi_powm(MPI res, MPI base, MPI exp, if (mod_shift_cnt) mpihelp_rshift(rp, rp, rsize, mod_shift_cnt); MPN_NORMALIZE(rp, rsize); - - mpihelp_release_karatsuba_ctx(&karactx); } if (negative_result && rsize) { @@ -313,6 +310,7 @@ int mpi_powm(MPI res, MPI base, MPI exp, leave: rc = 0; enomem: + mpihelp_release_karatsuba_ctx(&karactx); if (assign_rp) mpi_assign_limb_space(res, rp, size); if (mp_marker)