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=-20.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 DDFD1C6377A for ; Mon, 19 Jul 2021 16:29:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D0B8E61933 for ; Mon, 19 Jul 2021 16:29:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347350AbhGSPsi (ORCPT ); Mon, 19 Jul 2021 11:48:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:45840 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349556AbhGSPpK (ORCPT ); Mon, 19 Jul 2021 11:45:10 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9A0E261405; Mon, 19 Jul 2021 16:25:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626711931; bh=q2An+mu1ao07rcVJygd5q0JKjr0hlytbk9vYI4g09tU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VcKDo5XkuaxNuLc4WLV+AREhm4GK+gLtq/CwvxHWT/ZicBG9qXwiBAmX1UEcPDuhL 24InOfNRA28xY1l17NXYlyKwhxLVH96lzJQ0DqKAZavp0rL/ObqmpWDajMhfxVVHx9 XPaKluVmNt7Rhz+7Ov69p6s8who3C26iRm7uhGLM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Anna Schumaker , Trond Myklebust , Sasha Levin Subject: [PATCH 5.12 184/292] sunrpc: Avoid a KASAN slab-out-of-bounds bug in xdr_set_page_base() Date: Mon, 19 Jul 2021 16:54:06 +0200 Message-Id: <20210719144948.544201893@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210719144942.514164272@linuxfoundation.org> References: <20210719144942.514164272@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Anna Schumaker [ Upstream commit 6d1c0f3d28f98ea2736128ed3e46821496dc3a8c ] 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 Fixes: 8d86e373b0ef ("SUNRPC: Clean up helpers xdr_set_iov() and xdr_set_page_base()") Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin --- 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; -- 2.30.2