From patchwork Thu May 20 09:21:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 445658 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=-19.1 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 F1F16C43460 for ; Thu, 20 May 2021 10:09:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D71A161D61 for ; Thu, 20 May 2021 10:09:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234852AbhETKKX (ORCPT ); Thu, 20 May 2021 06:10:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:42284 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235669AbhETKHZ (ORCPT ); Thu, 20 May 2021 06:07:25 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id C50D861428; Thu, 20 May 2021 09:41:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1621503703; bh=YW47w+0iF8U084Kqnf+Fszc1K6VXKhqvgFO+TLTLQvk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iWygxHmEoBdBgQ35zk7CjCUG8Kjtm+kOSEziPhHjd7NK1opOA05PYnJk1bKwma7Ov hbFv8ChSbKB06Yaq+40lIuHzARrDfzsaSIVztOjCcshe8yDt5BJ/B/wG5SDfwQBo9Z 30rFsuXm1TlKPl6SzRDWSjlyspDoOhln/tSApa5k= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nikola Livic , Dan Carpenter , Trond Myklebust , Sasha Levin Subject: [PATCH 4.19 342/425] pNFS/flexfiles: fix incorrect size check in decode_nfs_fh() Date: Thu, 20 May 2021 11:21:51 +0200 Message-Id: <20210520092142.655278309@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210520092131.308959589@linuxfoundation.org> References: <20210520092131.308959589@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Nikola Livic [ Upstream commit ed34695e15aba74f45247f1ee2cf7e09d449f925 ] We (adam zabrocki, alexander matrosov, alexander tereshkin, maksym bazalii) observed the check: if (fh->size > sizeof(struct nfs_fh)) should not use the size of the nfs_fh struct which includes an extra two bytes from the size field. struct nfs_fh { unsigned short size; unsigned char data[NFS_MAXFHSIZE]; } but should determine the size from data[NFS_MAXFHSIZE] so the memcpy will not write 2 bytes beyond destination. The proposed fix is to compare against the NFS_MAXFHSIZE directly, as is done elsewhere in fs code base. Fixes: d67ae825a59d ("pnfs/flexfiles: Add the FlexFile Layout Driver") Signed-off-by: Nikola Livic Signed-off-by: Dan Carpenter Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin --- fs/nfs/flexfilelayout/flexfilelayout.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/nfs/flexfilelayout/flexfilelayout.c b/fs/nfs/flexfilelayout/flexfilelayout.c index d8cba46a9395..fee421da2197 100644 --- a/fs/nfs/flexfilelayout/flexfilelayout.c +++ b/fs/nfs/flexfilelayout/flexfilelayout.c @@ -101,7 +101,7 @@ static int decode_nfs_fh(struct xdr_stream *xdr, struct nfs_fh *fh) if (unlikely(!p)) return -ENOBUFS; fh->size = be32_to_cpup(p++); - if (fh->size > sizeof(struct nfs_fh)) { + if (fh->size > NFS_MAXFHSIZE) { printk(KERN_ERR "NFS flexfiles: Too big fh received %d\n", fh->size); return -EOVERFLOW;