From patchwork Wed Jun 9 21:07:29 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anna Schumaker X-Patchwork-Id: 12311159 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 4187DC48BCD for ; Wed, 9 Jun 2021 21:07:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1A6AB613C8 for ; Wed, 9 Jun 2021 21:07:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229557AbhFIVJh (ORCPT ); Wed, 9 Jun 2021 17:09:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42376 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229548AbhFIVJg (ORCPT ); Wed, 9 Jun 2021 17:09:36 -0400 Received: from mail-qk1-x730.google.com (mail-qk1-x730.google.com [IPv6:2607:f8b0:4864:20::730]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6083AC061574 for ; Wed, 9 Jun 2021 14:07:32 -0700 (PDT) Received: by mail-qk1-x730.google.com with SMTP id d196so20050696qkg.12 for ; Wed, 09 Jun 2021 14:07:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=8pcsXAvTnoFwx+NGnD5Y4krAjafFp+EXD/903HVtObQ=; b=NeRH6p931FGHKsz8zK4XREOF0B1o4ALNvT8kQsxP53vPyAfd96DaZ41pRoqo2tG8QD 6naT3SEcKk//GkY0IAz+TRXWCcseAsRjwiodWB78DfyAlEnPYp7hSHPo6utfdv4QdPLO TzZAJo3rpJJMvNPxTlKbLnKVQ8frmNV8thra04FioQuOtrhUBAThCewzLoBkI30iigXZ 3jWHywXzZ0rn/2hVvWZXbwoE5T8bPFOmg31cEUQTd3RgC/0fNVocMbcJAV5XZdCR2/uN 1GS49WfzByFZKyEWR0bUiA9tG+HY4ZLiAr0mnFkjPOfx1w6kC/7aq/f5dmu4itXfdezh oy5w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :mime-version:content-transfer-encoding; bh=8pcsXAvTnoFwx+NGnD5Y4krAjafFp+EXD/903HVtObQ=; b=nNKlyUnSWv1U3G/RIep3Z2fOEkmyX3t8taMyr3kyJSqrdXsJM5x6K8DnqLi15uJ/6+ lQPi+Gv1ZS5faUtgz3OpJEqPQ1FEA4SUCh7XTZAFuGpPhNAGhYZEztneNxG36aYyf+yU eD0n0rOlSuA6zL7Q1uJBI2CrdNVBjimi9d9Ey89n7rgcqmBAozSGQ+qWG5Fomv6CrTZn gBHJBoo8w0Yrtl/EpXmlQ5WZuddMOolKvLLNye/R2m00yChKApqbkyWfhByoJXGUnenX aR5JusFFMnyl4fMCN1xQL+b+gpYa4GYxJ2tM3RwFqVidmRUXrVXdXfzBY4VQf6hM9QAL 5kQQ== X-Gm-Message-State: AOAM532yq9kV05b+LrDMRqR8si5kwaB5fLwkUGZsyB+XpzfmADL1unSY boe6gKjGJPpxDDpTcNO4TJzFvewY5no= X-Google-Smtp-Source: ABdhPJwPlFUsL+OPCFqJV7/aKBwOOWld03TaorNIxioUvSeIK3E/ghLumPsLfq9P1r1nMr8aG19yEA== X-Received: by 2002:a37:a47:: with SMTP id 68mr1593837qkk.432.1623272851454; Wed, 09 Jun 2021 14:07:31 -0700 (PDT) Received: from localhost.localdomain ([2601:401:100:a3a:aa6d:aaff:fe2e:8a6a]) by smtp.gmail.com with ESMTPSA id g19sm871449qto.49.2021.06.09.14.07.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 09 Jun 2021 14:07:31 -0700 (PDT) Sender: Anna Schumaker From: schumaker.anna@gmail.com X-Google-Original-From: Anna.Schumaker@Netapp.com To: Trond.Myklebust@hammerspace.com, linux-nfs@vger.kernel.org Cc: Anna.Schumaker@Netapp.com Subject: [PATCH] sunrpc: Avoid a KASAN slab-out-of-bounds bug in xdr_set_page_base() Date: Wed, 9 Jun 2021 17:07:29 -0400 Message-Id: <20210609210729.254578-1-Anna.Schumaker@Netapp.com> X-Mailer: git-send-email 2.32.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org From: Anna Schumaker This seems to happen fairly easily during READ_PLUS testing on NFS v4.2. I found that we could end up accessing xdr->buf->pages[pgnr] with a pgnr greater than the number of pages in the array. So let's just return early if we're setting base to a point at the end of the page data and let xdr_set_tail_base() handle setting up the buffer pointers instead. Signed-off-by: Anna Schumaker --- net/sunrpc/xdr.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c index 3964ff74ee51..ca10ba2626f2 100644 --- a/net/sunrpc/xdr.c +++ b/net/sunrpc/xdr.c @@ -1230,10 +1230,9 @@ static unsigned int xdr_set_page_base(struct xdr_stream *xdr, void *kaddr; maxlen = xdr->buf->page_len; - if (base >= maxlen) { - base = maxlen; - maxlen = 0; - } else + if (base >= maxlen) + return 0; + else maxlen -= base; if (len > maxlen) len = maxlen;