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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 14574C43381 for ; Fri, 15 Feb 2019 19:58:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E080A21B18 for ; Fri, 15 Feb 2019 19:58:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726689AbfBOT6T (ORCPT ); Fri, 15 Feb 2019 14:58:19 -0500 Received: from fieldses.org ([173.255.197.46]:39632 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726317AbfBOT6T (ORCPT ); Fri, 15 Feb 2019 14:58:19 -0500 Received: by fieldses.org (Postfix, from userid 2815) id 1A5F61CE7; Fri, 15 Feb 2019 14:58:18 -0500 (EST) Date: Fri, 15 Feb 2019 14:58:18 -0500 From: "J. Bruce Fields" To: Scott Mayhew Cc: trond.myklebust@hammerspace.com, anna.schumaker@netapp.com, jlayton@kernel.org, linux-nfs@vger.kernel.org Subject: Re: [PATCH] sunrpc: fix 4 more call sites that were using stack memory with a scatterlist Message-ID: <20190215195818.GB22354@fieldses.org> References: <20190215184202.5537-1-smayhew@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190215184202.5537-1-smayhew@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org Thanks! Applying for 5.0 and stable. --b. On Fri, Feb 15, 2019 at 01:42:02PM -0500, Scott Mayhew wrote: > While trying to reproduce a reported kernel panic on arm64, I discovered > that AUTH_GSS basically doesn't work at all with older enctypes on arm64 > systems with CONFIG_VMAP_STACK enabled. It turns out there still a few > places using stack memory with scatterlists, causing krb5_encrypt() and > krb5_decrypt() to produce incorrect results (or a BUG if CONFIG_DEBUG_SG > is enabled). > > Tested with cthon on v4.0/v4.1/v4.2 with krb5/krb5i/krb5p using > des3-cbc-sha1 and arcfour-hmac-md5. > > Signed-off-by: Scott Mayhew > --- > net/sunrpc/auth_gss/gss_krb5_seqnum.c | 49 +++++++++++++++++++++------ > 1 file changed, 38 insertions(+), 11 deletions(-) > > diff --git a/net/sunrpc/auth_gss/gss_krb5_seqnum.c b/net/sunrpc/auth_gss/gss_krb5_seqnum.c > index fb6656295204..507105127095 100644 > --- a/net/sunrpc/auth_gss/gss_krb5_seqnum.c > +++ b/net/sunrpc/auth_gss/gss_krb5_seqnum.c > @@ -44,7 +44,7 @@ krb5_make_rc4_seq_num(struct krb5_ctx *kctx, int direction, s32 seqnum, > unsigned char *cksum, unsigned char *buf) > { > struct crypto_sync_skcipher *cipher; > - unsigned char plain[8]; > + unsigned char *plain; > s32 code; > > dprintk("RPC: %s:\n", __func__); > @@ -52,6 +52,10 @@ krb5_make_rc4_seq_num(struct krb5_ctx *kctx, int direction, s32 seqnum, > if (IS_ERR(cipher)) > return PTR_ERR(cipher); > > + plain = kmalloc(8, GFP_NOFS); > + if (!plain) > + return -ENOMEM; > + > plain[0] = (unsigned char) ((seqnum >> 24) & 0xff); > plain[1] = (unsigned char) ((seqnum >> 16) & 0xff); > plain[2] = (unsigned char) ((seqnum >> 8) & 0xff); > @@ -67,6 +71,7 @@ krb5_make_rc4_seq_num(struct krb5_ctx *kctx, int direction, s32 seqnum, > > code = krb5_encrypt(cipher, cksum, plain, buf, 8); > out: > + kfree(plain); > crypto_free_sync_skcipher(cipher); > return code; > } > @@ -77,12 +82,17 @@ krb5_make_seq_num(struct krb5_ctx *kctx, > u32 seqnum, > unsigned char *cksum, unsigned char *buf) > { > - unsigned char plain[8]; > + unsigned char *plain; > + s32 code; > > if (kctx->enctype == ENCTYPE_ARCFOUR_HMAC) > return krb5_make_rc4_seq_num(kctx, direction, seqnum, > cksum, buf); > > + plain = kmalloc(8, GFP_NOFS); > + if (!plain) > + return -ENOMEM; > + > plain[0] = (unsigned char) (seqnum & 0xff); > plain[1] = (unsigned char) ((seqnum >> 8) & 0xff); > plain[2] = (unsigned char) ((seqnum >> 16) & 0xff); > @@ -93,7 +103,9 @@ krb5_make_seq_num(struct krb5_ctx *kctx, > plain[6] = direction; > plain[7] = direction; > > - return krb5_encrypt(key, cksum, plain, buf, 8); > + code = krb5_encrypt(key, cksum, plain, buf, 8); > + kfree(plain); > + return code; > } > > static s32 > @@ -101,7 +113,7 @@ krb5_get_rc4_seq_num(struct krb5_ctx *kctx, unsigned char *cksum, > unsigned char *buf, int *direction, s32 *seqnum) > { > struct crypto_sync_skcipher *cipher; > - unsigned char plain[8]; > + unsigned char *plain; > s32 code; > > dprintk("RPC: %s:\n", __func__); > @@ -113,20 +125,28 @@ krb5_get_rc4_seq_num(struct krb5_ctx *kctx, unsigned char *cksum, > if (code) > goto out; > > + plain = kmalloc(8, GFP_NOFS); > + if (!plain) { > + code = -ENOMEM; > + goto out; > + } > + > code = krb5_decrypt(cipher, cksum, buf, plain, 8); > if (code) > - goto out; > + goto out_plain; > > if ((plain[4] != plain[5]) || (plain[4] != plain[6]) > || (plain[4] != plain[7])) { > code = (s32)KG_BAD_SEQ; > - goto out; > + goto out_plain; > } > > *direction = plain[4]; > > *seqnum = ((plain[0] << 24) | (plain[1] << 16) | > (plain[2] << 8) | (plain[3])); > +out_plain: > + kfree(plain); > out: > crypto_free_sync_skcipher(cipher); > return code; > @@ -139,7 +159,7 @@ krb5_get_seq_num(struct krb5_ctx *kctx, > int *direction, u32 *seqnum) > { > s32 code; > - unsigned char plain[8]; > + unsigned char *plain; > struct crypto_sync_skcipher *key = kctx->seq; > > dprintk("RPC: krb5_get_seq_num:\n"); > @@ -147,18 +167,25 @@ krb5_get_seq_num(struct krb5_ctx *kctx, > if (kctx->enctype == ENCTYPE_ARCFOUR_HMAC) > return krb5_get_rc4_seq_num(kctx, cksum, buf, > direction, seqnum); > + plain = kmalloc(8, GFP_NOFS); > + if (!plain) > + return -ENOMEM; > > if ((code = krb5_decrypt(key, cksum, buf, plain, 8))) > - return code; > + goto out; > > if ((plain[4] != plain[5]) || (plain[4] != plain[6]) || > - (plain[4] != plain[7])) > - return (s32)KG_BAD_SEQ; > + (plain[4] != plain[7])) { > + code = (s32)KG_BAD_SEQ; > + goto out; > + } > > *direction = plain[4]; > > *seqnum = ((plain[0]) | > (plain[1] << 8) | (plain[2] << 16) | (plain[3] << 24)); > > - return 0; > +out: > + kfree(plain); > + return code; > } > -- > 2.17.2