From patchwork Mon Apr 29 22:09:32 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andreas Gruenbacher X-Patchwork-Id: 10922573 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 A52B31395 for ; Mon, 29 Apr 2019 22:09:53 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 95F50285BA for ; Mon, 29 Apr 2019 22:09:53 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8A229287EA; Mon, 29 Apr 2019 22:09:53 +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 355C5285BA for ; Mon, 29 Apr 2019 22:09:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729547AbfD2WJw (ORCPT ); Mon, 29 Apr 2019 18:09:52 -0400 Received: from mx1.redhat.com ([209.132.183.28]:46734 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728105AbfD2WJw (ORCPT ); Mon, 29 Apr 2019 18:09:52 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 2E63C308624B; Mon, 29 Apr 2019 22:09:52 +0000 (UTC) Received: from max.home.com (unknown [10.40.205.80]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7467717CCB; Mon, 29 Apr 2019 22:09:49 +0000 (UTC) From: Andreas Gruenbacher To: cluster-devel@redhat.com, "Darrick J . Wong" Cc: Christoph Hellwig , 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 v7 3/5] iomap: Fix use-after-free error in page_done callback Date: Tue, 30 Apr 2019 00:09:32 +0200 Message-Id: <20190429220934.10415-4-agruenba@redhat.com> In-Reply-To: <20190429220934.10415-1-agruenba@redhat.com> References: <20190429220934.10415-1-agruenba@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.49]); Mon, 29 Apr 2019 22:09:52 +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're 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 Reviewed-by: Jan Kara Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong --- fs/buffer.c | 2 +- fs/iomap.c | 1 + 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/buffer.c b/fs/buffer.c index e0d4c6a5e2d2..0faa41fb4c88 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -2104,7 +2104,6 @@ void __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); @@ -2160,6 +2159,7 @@ int generic_write_end(struct file *file, struct address_space *mapping, { copied = block_write_end(file, mapping, pos, len, copied, page, fsdata); __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 f8c9722d1a97..62e3461704ce 100644 --- a/fs/iomap.c +++ b/fs/iomap.c @@ -780,6 +780,7 @@ iomap_write_end(struct inode *inode, loff_t pos, unsigned len, __generic_write_end(inode, pos, ret, page); if (iomap->page_done) iomap->page_done(inode, pos, copied, page, iomap); + put_page(page); if (ret < len) iomap_write_failed(inode, pos, len);