From patchwork Mon Jul 12 06:00:55 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 475602 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=-19.4 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, URIBL_BLOCKED, 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 91DD0C11F6A for ; Mon, 12 Jul 2021 07:30:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 753EA611BF for ; Mon, 12 Jul 2021 07:30:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240877AbhGLHcp (ORCPT ); Mon, 12 Jul 2021 03:32:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:48702 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346688AbhGLHbD (ORCPT ); Mon, 12 Jul 2021 03:31:03 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B648461006; Mon, 12 Jul 2021 07:28:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626074894; bh=kpBqSebfWgQEbDKLxzqVObLHgHlgpXbNuvTDeg9xsNc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QXRHTbILKLJBdshLKdltijb8oSDh46eijjJVcgiZZSSDZpw36JJrnztjtzj6Gg7W6 WZkAstm7C7FWmvG/i+ZPU+drFmqt+fMwkO11ypNgtfdxOGHDKGkGWziS6i3EfNDMV7 RLtWT8GL01Rz2NEEzowRrv6h6ZzDufRJpke27t2A= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Bob Peterson , Andreas Gruenbacher Subject: [PATCH 5.13 032/800] gfs2: Fix underflow in gfs2_page_mkwrite Date: Mon, 12 Jul 2021 08:00:55 +0200 Message-Id: <20210712060917.749912640@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210712060912.995381202@linuxfoundation.org> References: <20210712060912.995381202@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Andreas Gruenbacher commit d3c51c55cb9274dd43c156f1f26b5eb4d5f2d58c upstream. On filesystems with a block size smaller than PAGE_SIZE and non-empty files smaller then PAGE_SIZE, gfs2_page_mkwrite could end up allocating excess blocks beyond the end of the file, similar to fallocate. This doesn't make sense; fix it. Reported-by: Bob Peterson Fixes: 184b4e60853d ("gfs2: Fix end-of-file handling in gfs2_page_mkwrite") Cc: stable@vger.kernel.org # v5.5+ Signed-off-by: Andreas Gruenbacher Signed-off-by: Greg Kroah-Hartman --- fs/gfs2/file.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/fs/gfs2/file.c +++ b/fs/gfs2/file.c @@ -450,8 +450,8 @@ static vm_fault_t gfs2_page_mkwrite(stru file_update_time(vmf->vma->vm_file); /* page is wholly or partially inside EOF */ - if (offset > size - PAGE_SIZE) - length = offset_in_page(size); + if (size - offset < PAGE_SIZE) + length = size - offset; else length = PAGE_SIZE;