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=-3.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 8447AC4332D for ; Thu, 19 Mar 2020 04:36:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5866B20757 for ; Thu, 19 Mar 2020 04:36:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="FK+oh8+k" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725787AbgCSEg1 (ORCPT ); Thu, 19 Mar 2020 00:36:27 -0400 Received: from frisell.zx2c4.com ([192.95.5.64]:41735 "EHLO frisell.zx2c4.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725601AbgCSEg1 (ORCPT ); Thu, 19 Mar 2020 00:36:27 -0400 Received: by frisell.zx2c4.com (ZX2C4 Mail Server) with ESMTP id 925fe938; Thu, 19 Mar 2020 04:30:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=zx2c4.com; h=mime-version :references:in-reply-to:from:date:message-id:subject:to:cc :content-type; s=mail; bh=+s2FzirMB0tlloariI/IcCb8oyc=; b=FK+oh8 +kTiQrNR+RQf497KyPeLBun7Pt/xmB8nKb5wFXjc8Kh/FPxpHm/YcuY/c/UjWH5y 3RwUHzSHH7WfAuOtEPOdm9l4guCBxQ5l1w0m4GXFBNHFa8rgUCVRqa2YZx3zllOd TSx2zq1nhSIFF/W4qXuxAYSDdZzK68VCuCIwY5gMKN2cbZFnf/uZio6kqcB9U6kC 4x9f0/wyIPraPCXYoaOPaYX2Z0qxiiMwKzegIrxxmS0elEmvjwM9VR6TSq2if66+ WBv1gokoNGJ4YYISvFdo2g/y7VEwXQfJCrk3XtTJ6razqIHUjF37tcMRz4UMFOzM Lqj7Bh0uFPEU1dGw== Received: by frisell.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id b03adda6 (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256:NO); Thu, 19 Mar 2020 04:29:58 +0000 (UTC) Received: by mail-il1-f179.google.com with SMTP id p1so1018299ils.5; Wed, 18 Mar 2020 21:36:24 -0700 (PDT) X-Gm-Message-State: ANhLgQ2vbqw8m/piboOdH9O/0iQSb2pEwr6jcGa21yR8bAdK7nWsEIY3 AWKQuYPY5U/Pujd9SGS4lVehCL4JLNQUaGAxqkw= X-Google-Smtp-Source: ADFU+vvf9AsZriRw4R+MQ2btVMLhM7//ex/Lj+zPbU7bBo6NKPrcPmpj5qASRSvJQHh9LZzrSUW12e6/1cVA23qNtZc= X-Received: by 2002:a92:358b:: with SMTP id c11mr1400687ilf.64.1584592584049; Wed, 18 Mar 2020 21:36:24 -0700 (PDT) MIME-Version: 1.0 References: <20200319022732.166085-1-Jason@zx2c4.com> <20200319032526.GH2334@sol.localdomain> In-Reply-To: From: "Jason A. Donenfeld" Date: Wed, 18 Mar 2020 22:36:13 -0600 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH URGENT crypto v2] crypto: arm64/chacha - correctly walk through blocks To: Eric Biggers Cc: LKML , Linux Crypto Mailing List , Greg Kroah-Hartman , Herbert Xu , Emil Renner Berthing , Ard Biesheuvel , stable Content-Type: text/plain; charset="UTF-8" Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org On Wed, Mar 18, 2020 at 10:25 PM Jason A. Donenfeld wrote: > > On Wed, Mar 18, 2020 at 9:25 PM Eric Biggers wrote: > > > > On Wed, Mar 18, 2020 at 08:27:32PM -0600, Jason A. Donenfeld wrote: > > > It also fixes up a bug in the (optional, costly) stride test that > > > prevented it from running on arm64. > > [...] > > > diff --git a/lib/crypto/chacha20poly1305-selftest.c b/lib/crypto/chacha20poly1305-selftest.c > > > index c391a91364e9..fa43deda2660 100644 > > > --- a/lib/crypto/chacha20poly1305-selftest.c > > > +++ b/lib/crypto/chacha20poly1305-selftest.c > > > @@ -9028,10 +9028,15 @@ bool __init chacha20poly1305_selftest(void) > > > && total_len <= 1 << 10; ++total_len) { > > > for (i = 0; i <= total_len; ++i) { > > > for (j = i; j <= total_len; ++j) { > > > + k = 0; > > > sg_init_table(sg_src, 3); > > > - sg_set_buf(&sg_src[0], input, i); > > > - sg_set_buf(&sg_src[1], input + i, j - i); > > > - sg_set_buf(&sg_src[2], input + j, total_len - j); > > > + if (i) > > > + sg_set_buf(&sg_src[k++], input, i); > > > + if (j - i) > > > + sg_set_buf(&sg_src[k++], input + i, j - i); > > > + if (total_len - j) > > > + sg_set_buf(&sg_src[k++], input + j, total_len - j); > > > + sg_init_marker(sg_src, k); > > > memset(computed_output, 0, total_len); > > > memset(input, 0, total_len); > > > > So with this test fix, does this test find the bug? > > Yes. > > > Apparently the empty scatterlist elements caused some problem? What was > > that problem exactly? And what do you mean by this "prevented the test > > from running on arm64"? If there is a problem it seems we should > > something else about about it, e.g. debug checks that work in consistent > > way on all architectures, documenting what the function expects, or make > > it just work properly with empty scatterlist elements. > > Yea, my next plan was to look into what's going on there. In case > you're curious, here's what happens: > > [ 0.355761] [ffffffff041e9508] pgd=000000004ffe9003, > pud=000000004ffe9003, pmd=0000000000000000 > [ 0.356212] Internal error: Oops: 96000006 [#1] PREEMPT SMP > [ 0.356587] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.6.0-rc5+ #10 > [ 0.356695] Hardware name: linux,dummy-virt (DT) > [ 0.356972] pstate: 20000005 (nzCv daif -PAN -UAO) > [ 0.357158] pc : scatterwalk_copychunks+0x13c/0x1e0 > [ 0.357257] lr : scatterwalk_copychunks+0xe0/0x1e0 > [ 0.357379] sp : ffffff800f82f970 > [ 0.357450] x29: ffffff800f82f970 x28: ffffff800f838000 > [ 0.357607] x27: ffffff800f838000 x26: 0000000000000001 > [ 0.357725] x25: ffffff800f82faf0 x24: ffffff800f82fa10 > [ 0.357820] x23: 0000000000000010 x22: 0000000000000000 > [ 0.357898] x21: 0000000000000000 x20: 0000000100200000 > [ 0.357978] x19: ffffff8000000000 x18: 0000000000000014 > [ 0.358132] x17: 0000000000000000 x16: 0000000000000002 > [ 0.358214] x15: 00000000074c5755 x14: 0000000000000002 > [ 0.358310] x13: 074c57550311ac67 x12: 09579e470077af1a > [ 0.358453] x11: 1d3f98018ec6f5bb x10: 3e6144a223343e11 > [ 0.358560] x9 : 0000000000000000 x8 : ffffff800f82fcc0 > [ 0.358638] x7 : 0000000000000000 x6 : ffffff800fa55000 > [ 0.358711] x5 : 0000000000001000 x4 : 0000000000000000 > [ 0.358781] x3 : ffffffff001e9540 x2 : ffffffff001e9540 > [ 0.358855] x1 : ffffffff041e9500 x0 : ffffff800f82fd60 > [ 0.359007] Call trace: > [ 0.359177] scatterwalk_copychunks+0x13c/0x1e0 > [ 0.359269] scatterwalk_map_and_copy+0x50/0xa8 > [ 0.359339] chacha20poly1305_crypt_sg_inplace+0x3f4/0x418 > [ 0.359418] chacha20poly1305_encrypt_sg_inplace+0x10/0x18 > [ 0.359511] chacha20poly1305_selftest+0x4dc/0x618 > [ 0.359581] mod_init+0xc/0x2c > [ 0.359630] do_one_initcall+0x58/0x11c > [ 0.359687] kernel_init_freeable+0x174/0x1e0 > [ 0.359751] kernel_init+0x10/0x100 > [ 0.359803] ret_from_fork+0x10/0x18 > [ 0.360074] Code: f9400002 530c7c21 927ef442 8b011841 (f9400423) > [ 0.360257] ---[ end trace 0b64264f8a25dbdf ]--- > [ 0.360453] Kernel panic - not syncing: Fatal exception > [ 0.360597] SMP: stopping secondary CPUs > [ 0.360835] Kernel Offset: disabled > [ 0.360985] CPU features: 0x00002,00002000 > [ 0.361042] Memory Limit: none __read_once_size at include/linux/compiler.h:199 (inlined by) compound_head at include/linux/page-flags.h:174 (inlined by) PageSlab at include/linux/page-flags.h:325 (inlined by) scatterwalk_pagedone at include/crypto/scatterwalk.h:88 (inlined by) scatterwalk_copychunks at crypto/scatterwalk.c:50 Bug makes sense. scatterwalk_copychunks->scatterwalk_pagedone->PageSlab, but length zero page means we're looking at nonsense. So this v2 seems to be the correct fix.