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=-20.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,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 25D4DC07E95 for ; Mon, 19 Jul 2021 15:59:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1082861165 for ; Mon, 19 Jul 2021 15:59:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243623AbhGSPSp (ORCPT ); Mon, 19 Jul 2021 11:18:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:42484 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344732AbhGSOtI (ORCPT ); Mon, 19 Jul 2021 10:49:08 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 489D160551; Mon, 19 Jul 2021 15:29:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626708586; bh=y/npxEBPgWx6Nj/RGcHLzEbTg//DYvL0MZX+fQFqi4A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Soxt/bQ7BYTe75RTem6CrRVQHOSSyHYsbaOlR8mBde7/gBnGwbwkpoLLF/r4hUvtM ZHfAuEcsTtCXJ8B9I/xbJTZ3ysoiq+G6QaIwSREfwM9P7sMl+5NAFCOMpxlLXOtt3x KM0oegfJEyCcfv7ScH8lo9EtvhwmLhfkjgC5DkO8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Pradeep P V K , Miklos Szeredi Subject: [PATCH 4.19 050/421] fuse: check connected before queueing on fpq->io Date: Mon, 19 Jul 2021 16:47:41 +0200 Message-Id: <20210719144947.959746296@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210719144946.310399455@linuxfoundation.org> References: <20210719144946.310399455@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Miklos Szeredi commit 80ef08670d4c28a06a3de954bd350368780bcfef upstream. A request could end up on the fpq->io list after fuse_abort_conn() has reset fpq->connected and aborted requests on that list: Thread-1 Thread-2 ======== ======== ->fuse_simple_request() ->shutdown ->__fuse_request_send() ->queue_request() ->fuse_abort_conn() ->fuse_dev_do_read() ->acquire(fpq->lock) ->wait_for(fpq->lock) ->set err to all req's in fpq->io ->release(fpq->lock) ->acquire(fpq->lock) ->add req to fpq->io After the userspace copy is done the request will be ended, but req->out.h.error will remain uninitialized. Also the copy might block despite being already aborted. Fix both issues by not allowing the request to be queued on the fpq->io list after fuse_abort_conn() has processed this list. Reported-by: Pradeep P V K Fixes: fd22d62ed0c3 ("fuse: no fc->lock for iqueue parts") Cc: # v4.2 Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman --- fs/fuse/dev.c | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -1310,6 +1310,15 @@ static ssize_t fuse_dev_do_read(struct f goto restart; } spin_lock(&fpq->lock); + /* + * Must not put request on fpq->io queue after having been shut down by + * fuse_abort_conn() + */ + if (!fpq->connected) { + req->out.h.error = err = -ECONNABORTED; + goto out_end; + + } list_add(&req->list, &fpq->io); spin_unlock(&fpq->lock); cs->req = req;