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 1A2A8C3A59F for ; Thu, 29 Aug 2019 18:15:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DA86123429 for ; Thu, 29 Aug 2019 18:15:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567102539; bh=JvqJEB55stf2gf4IFOdP9UEaXddRwXadDHyrHsyqYa8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=VODB5NKe4qPbz26OJYElrHMfxXMe7kpbckulr9XI94hK80PhL74/5b7eH96SjoFzl LR/DWMDPR0ZUe03c+mUwf+gpqbsIxcZ6MBsopph9qnamYwspP9zvLAIbJ19Um2UEFo akL+KJuwimUftWXTu8M81JjwLA7HnMQjIU/McV30= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728592AbfH2SPi (ORCPT ); Thu, 29 Aug 2019 14:15:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:57302 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729344AbfH2SPg (ORCPT ); Thu, 29 Aug 2019 14:15:36 -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 EB83423404; Thu, 29 Aug 2019 18:15:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567102535; bh=JvqJEB55stf2gf4IFOdP9UEaXddRwXadDHyrHsyqYa8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=A+JsQlVX8kGVgjvXj19Xp1yVSF9sC7SKtrGXa74UtY5tRc68KZY1V4bJ5zld6HgGi 7Izc/4+Niv9rk52BDjKDqOFTmdpxzzpwmywVQYcoV0PvF9E6gJC1uq7StXxUFXkXVv BM+x1WWAHTvyDpA5JM6EUmDaXpsfoYm3dOOr8SDY= 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 5.2 70/76] afs: Fix leak in afs_lookup_cell_rcu() Date: Thu, 29 Aug 2019 14:13:05 -0400 Message-Id: <20190829181311.7562-70-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190829181311.7562-1-sashal@kernel.org> References: <20190829181311.7562-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 a2a87117d2626..fd5133e26a38b 100644 --- a/fs/afs/cell.c +++ b/fs/afs/cell.c @@ -74,6 +74,7 @@ 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; @@ -108,6 +109,9 @@ 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