From patchwork Fri Apr 26 13:11:25 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andreas Gruenbacher X-Patchwork-Id: 10919119 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 204D61398 for ; Fri, 26 Apr 2019 13:11:38 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0B43728D0D for ; Fri, 26 Apr 2019 13:11:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id F084D28DD0; Fri, 26 Apr 2019 13:11:37 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9130628D0D for ; Fri, 26 Apr 2019 13:11:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726069AbfDZNLh (ORCPT ); Fri, 26 Apr 2019 09:11:37 -0400 Received: from mx1.redhat.com ([209.132.183.28]:46050 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725901AbfDZNLg (ORCPT ); Fri, 26 Apr 2019 09:11:36 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C42F4883B8; Fri, 26 Apr 2019 13:11:36 +0000 (UTC) Received: from max.home.com (unknown [10.40.205.80]) by smtp.corp.redhat.com (Postfix) with ESMTP id E1ECE648D6; Fri, 26 Apr 2019 13:11:30 +0000 (UTC) From: Andreas Gruenbacher To: cluster-devel@redhat.com, Christoph Hellwig Cc: Bob Peterson , Jan Kara , Dave Chinner , Ross Lagerwall , Mark Syms , =?utf-8?b?RWR3aW4gVMO2csO2aw==?= , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Andreas Gruenbacher Subject: [PATCH v5 1/3] iomap: Fix use-after-free error in page_done callback Date: Fri, 26 Apr 2019 15:11:25 +0200 Message-Id: <20190426131127.19164-1-agruenba@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Fri, 26 Apr 2019 13:11:36 +0000 (UTC) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP In iomap_write_end, we are not holding a page reference anymore when calling the page_done callback, but the callback needs that reference to access the page. To fix that, move the put_page call in __generic_write_end into the callers of __generic_write_end. Then, in iomap_write_end, put the page after calling the page_done callback. Reported-by: Jan Kara Fixes: 63899c6f8851 ("iomap: add a page_done callback") Signed-off-by: Andreas Gruenbacher Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara --- fs/buffer.c | 5 +++-- fs/iomap.c | 12 ++++++++++-- 2 files changed, 13 insertions(+), 4 deletions(-) diff --git a/fs/buffer.c b/fs/buffer.c index ce357602f471..6e2c95160ce3 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -2104,7 +2104,6 @@ int __generic_write_end(struct inode *inode, loff_t pos, unsigned copied, } unlock_page(page); - put_page(page); if (old_size < pos) pagecache_isize_extended(inode, old_size, pos); @@ -2160,7 +2159,9 @@ int generic_write_end(struct file *file, struct address_space *mapping, struct page *page, void *fsdata) { copied = block_write_end(file, mapping, pos, len, copied, page, fsdata); - return __generic_write_end(mapping->host, pos, copied, page); + copied = __generic_write_end(mapping->host, pos, copied, page); + put_page(page); + return copied; } EXPORT_SYMBOL(generic_write_end); diff --git a/fs/iomap.c b/fs/iomap.c index 97cb9d486a7d..3e4652dac9d9 100644 --- a/fs/iomap.c +++ b/fs/iomap.c @@ -765,6 +765,14 @@ iomap_write_end_inline(struct inode *inode, struct page *page, return copied; } +static int +buffer_write_end(struct address_space *mapping, loff_t pos, loff_t len, + unsigned copied, struct page *page) +{ + copied = block_write_end(NULL, mapping, pos, len, copied, page, NULL); + return __generic_write_end(mapping->host, pos, copied, page); +} + static int iomap_write_end(struct inode *inode, loff_t pos, unsigned len, unsigned copied, struct page *page, struct iomap *iomap) @@ -774,14 +782,14 @@ iomap_write_end(struct inode *inode, loff_t pos, unsigned len, if (iomap->type == IOMAP_INLINE) { ret = iomap_write_end_inline(inode, page, iomap, pos, copied); } else if (iomap->flags & IOMAP_F_BUFFER_HEAD) { - ret = generic_write_end(NULL, inode->i_mapping, pos, len, - copied, page, NULL); + ret = buffer_write_end(inode->i_mapping, pos, len, copied, page); } else { ret = __iomap_write_end(inode, pos, len, copied, page, iomap); } if (iomap->page_done) iomap->page_done(inode, pos, copied, page, iomap); + put_page(page); if (ret < len) iomap_write_failed(inode, pos, len);