From patchwork Thu Mar 9 18:58:27 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 9613927 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 5EF7F60417 for ; Thu, 9 Mar 2017 18:59:45 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5897628654 for ; Thu, 9 Mar 2017 18:59:45 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4D0AE28660; Thu, 9 Mar 2017 18:59:45 +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=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable 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 EBB9828654 for ; Thu, 9 Mar 2017 18:59:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933211AbdCIS6b (ORCPT ); Thu, 9 Mar 2017 13:58:31 -0500 Received: from mx1.redhat.com ([209.132.183.28]:33362 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933053AbdCIS6a (ORCPT ); Thu, 9 Mar 2017 13:58:30 -0500 Received: from smtp.corp.redhat.com (int-mx16.intmail.prod.int.phx2.redhat.com [10.5.11.28]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 5FC2D85A07; Thu, 9 Mar 2017 18:58:30 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.10.120.66]) by smtp.corp.redhat.com (Postfix) with ESMTP id 736AB2D655; Thu, 9 Mar 2017 18:58:29 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 23/27] afs: Fix page leak in afs_write_begin() From: David Howells To: viro@ZenIV.linux.org.uk Cc: dhowells@redhat.com, linux-fsdevel@vger.kernel.org, linux-afs@lists.infradead.org, linux-kernel@vger.kernel.org Date: Thu, 09 Mar 2017 18:58:27 +0000 Message-ID: <148908590776.16794.7230863874143141245.stgit@warthog.procyon.org.uk> In-Reply-To: <148908574888.16794.14109877851518811944.stgit@warthog.procyon.org.uk> References: <148908574888.16794.14109877851518811944.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.74 on 10.5.11.28 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Thu, 09 Mar 2017 18:58:30 +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 afs_write_begin() leaks a ref and a lock on a page if afs_fill_page() fails. Fix the leak by unlocking and releasing the page in the error path. Signed-off-by: David Howells --- fs/afs/write.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/fs/afs/write.c b/fs/afs/write.c index f1450ea09406..6e13e96c3db0 100644 --- a/fs/afs/write.c +++ b/fs/afs/write.c @@ -154,12 +154,12 @@ int afs_write_begin(struct file *file, struct address_space *mapping, kfree(candidate); return -ENOMEM; } - *pagep = page; - /* page won't leak in error case: it eventually gets cleaned off LRU */ if (!PageUptodate(page) && len != PAGE_SIZE) { ret = afs_fill_page(vnode, key, pos & PAGE_MASK, PAGE_SIZE, page); if (ret < 0) { + unlock_page(page); + put_page(page); kfree(candidate); _leave(" = %d [prep]", ret); return ret; @@ -167,6 +167,9 @@ int afs_write_begin(struct file *file, struct address_space *mapping, SetPageUptodate(page); } + /* page won't leak in error case: it eventually gets cleaned off LRU */ + *pagep = page; + try_again: spin_lock(&vnode->writeback_lock);