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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 62661C43219 for ; Mon, 29 Apr 2019 22:09:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2EBAA2075E 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?q?Edwin=20T=C3=B6r=C3=B6k?= , 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 Content-Transfer-Encoding: 8bit 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 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 --- 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); -- 2.20.1 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andreas Gruenbacher Date: Tue, 30 Apr 2019 00:09:32 +0200 Subject: [Cluster-devel] [PATCH v7 3/5] iomap: Fix use-after-free error in page_done callback In-Reply-To: <20190429220934.10415-1-agruenba@redhat.com> References: <20190429220934.10415-1-agruenba@redhat.com> Message-ID: <20190429220934.10415-4-agruenba@redhat.com> List-Id: To: cluster-devel.redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit 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 --- 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); -- 2.20.1