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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 535DEC3A59F for ; Thu, 29 Aug 2019 18:23:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1F52E21874 for ; Thu, 29 Aug 2019 18:23:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567103008; bh=JfugwJoZrrcuXr7gxgP+D6FbKzm1spHA1BgCwXHQ4GA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=p0nkcnT8fqeo27L/T3Yha+DqYUqk8Qw45HaMPqh2TODobq6kVHdG5+uyN38bFSKme 6QSNpGuHEUNhf+Sc7+c/sO+6ntOXJCpYEE9CmWECQ6zoAH18zqKm5bv8iPt1V1HCv5 NKCfTfyQXCyh54AjMfhCWlVitpuwG3HVL8zEW9Ws= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728259AbfH2SX0 (ORCPT ); Thu, 29 Aug 2019 14:23:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:58926 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728488AbfH2SQv (ORCPT ); Thu, 29 Aug 2019 14:16:51 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0DCBA2189D; Thu, 29 Aug 2019 18:16:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567102610; bh=JfugwJoZrrcuXr7gxgP+D6FbKzm1spHA1BgCwXHQ4GA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Dp/Jur9Ya1Hz7dxqlXHVGBWranCQQbnva3yUu8GluHcDH821GnNO6o1lb83yH32aZ vJRKwoH4aCrhK2smDWsK+lKz5NX6KsQ9DWhHc/xn/zZ1HcXX1I4bqPqc4lE028IJBz aHEVUkzHmtYT70KHvgGiBZtLSeZ8JdHg/NVX4eQc= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: David Howells , Sasha Levin , linux-afs@lists.infradead.org Subject: [PATCH AUTOSEL 4.19 44/45] afs: Fix leak in afs_lookup_cell_rcu() Date: Thu, 29 Aug 2019 14:15:44 -0400 Message-Id: <20190829181547.8280-44-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190829181547.8280-1-sashal@kernel.org> References: <20190829181547.8280-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: David Howells [ 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