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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 40584C4332F for ; Sun, 8 Sep 2019 12:57:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0AC442082C for ; Sun, 8 Sep 2019 12:57:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567947424; bh=lFnABTanQs6IkhrV1YIcC5mhDXDuSQ4tMUwczAbIc5Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=SplnEMqEgavEuQq1qujA7lLxPWrhsjdXLfiegoWKS/jM7o/G7Bcr72wIHhWihZxmM Jli2TjyZh1bu3SuYZSLFDg3uVU/Mezy0OSriFOmF3kfDyzYcpdNp4MTtFC1MV0y/h9 Wd9tR24AP8gFJlGxBM8ehcF8dVbzK5W2RSA05JGM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731186AbfIHMsw (ORCPT ); Sun, 8 Sep 2019 08:48:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:38164 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731174AbfIHMss (ORCPT ); Sun, 8 Sep 2019 08:48:48 -0400 Received: from localhost (unknown [62.28.240.114]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7646A218AF; Sun, 8 Sep 2019 12:48:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567946928; bh=lFnABTanQs6IkhrV1YIcC5mhDXDuSQ4tMUwczAbIc5Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yvhUQrhB1hrkDtcfUnExTC21utB7fC0+juXMqmN/SXgl6bBKw9zmXNLWsxB8gz6Ew 9Yhqw0DLId6NYB58GXrjYaRht8ab2CEOWntZsWcQ50BvJfsaz66hD27dKwPG8M+imT mn6O8aDreH4FtyWBCVgq+DTdPYytjB/v2Hww6zs4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, David Howells , Sasha Levin Subject: [PATCH 4.19 53/57] afs: Fix leak in afs_lookup_cell_rcu() Date: Sun, 8 Sep 2019 13:42:17 +0100 Message-Id: <20190908121146.244098641@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190908121125.608195329@linuxfoundation.org> References: <20190908121125.608195329@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org [ Upstream commit a5fb8e6c02d6a518fb2b1a2b8c2471fa77b69436 ] Fix a leak on the cell refcount in afs_lookup_cell_rcu() due to non-clearance of the default error in the case a NULL cell name is passed and the workstation default cell is used. Also put a bit at the end to make sure we don't leak a cell ref if we're going to be returning an error. This leak results in an assertion like the following when the kafs module is unloaded: AFS: Assertion failed 2 == 1 is false 0x2 == 0x1 is false ------------[ cut here ]------------ kernel BUG at fs/afs/cell.c:770! ... RIP: 0010:afs_manage_cells+0x220/0x42f [kafs] ... process_one_work+0x4c2/0x82c ? pool_mayday_timeout+0x1e1/0x1e1 ? do_raw_spin_lock+0x134/0x175 worker_thread+0x336/0x4a6 ? rescuer_thread+0x4af/0x4af kthread+0x1de/0x1ee ? kthread_park+0xd4/0xd4 ret_from_fork+0x24/0x30 Fixes: 989782dcdc91 ("afs: Overhaul cell database management") Signed-off-by: David Howells Signed-off-by: Sasha Levin --- fs/afs/cell.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/afs/cell.c b/fs/afs/cell.c index 6127f0fcd62c4..ee07162d35c7a 100644 --- a/fs/afs/cell.c +++ b/fs/afs/cell.c @@ -76,6 +76,7 @@ struct afs_cell *afs_lookup_cell_rcu(struct afs_net *net, cell = rcu_dereference_raw(net->ws_cell); if (cell) { afs_get_cell(cell); + ret = 0; break; } ret = -EDESTADDRREQ; @@ -110,6 +111,9 @@ struct afs_cell *afs_lookup_cell_rcu(struct afs_net *net, done_seqretry(&net->cells_lock, seq); + if (ret != 0 && cell) + afs_put_cell(net, cell); + return ret == 0 ? cell : ERR_PTR(ret); } -- 2.20.1