From patchwork Mon Jul 12 06:07:26 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 476386 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=-19.4 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, URIBL_BLOCKED, 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 DBA66C11F66 for ; Mon, 12 Jul 2021 06:17:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C82F6610CA for ; Mon, 12 Jul 2021 06:17:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233780AbhGLGUH (ORCPT ); Mon, 12 Jul 2021 02:20:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:38010 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233967AbhGLGTh (ORCPT ); Mon, 12 Jul 2021 02:19:37 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 666C9610A6; Mon, 12 Jul 2021 06:16:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626070608; bh=/Y1Mkf1M+k2dxpIKYjn3JBq+L2doUleTpDIx/Ixafmc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ISOMi7bijXIZLYSfaoukjky8ua5C/RXPYFD5A7zjzx4Yy1r1TKMUIP6pgJtmSvisj Ke9MkKuPcjkjLZUsjXAfo64Xs28vINskZidAFz6sj2yr6fGeeYYpwCDlIUHJMEH4fb K/EFRTdQdTibmsytnmslbVDhzC/7l7kmNUWsV+NQ= 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 5.4 062/348] fuse: check connected before queueing on fpq->io Date: Mon, 12 Jul 2021 08:07:26 +0200 Message-Id: <20210712060710.230878713@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210712060659.886176320@linuxfoundation.org> References: <20210712060659.886176320@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@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 @@ -1264,6 +1264,15 @@ 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;