From patchwork Thu Sep 17 10:06:11 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oliver Neukum X-Patchwork-Id: 258524 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=-12.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,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 70D75C433E2 for ; Thu, 17 Sep 2020 10:06:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 312AC2083B for ; Thu, 17 Sep 2020 10:06:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=suse.com header.i=@suse.com header.b="hsf4IaSZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726584AbgIQKGq (ORCPT ); Thu, 17 Sep 2020 06:06:46 -0400 Received: from mx2.suse.de ([195.135.220.15]:37668 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726524AbgIQKGd (ORCPT ); Thu, 17 Sep 2020 06:06:33 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=cantorsusede; t=1600337189; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:in-reply-to:in-reply-to:references:references; bh=02ogVbl2/wFuqInSwBJuVrTNQykLfclOjm8SmDAqKiE=; b=hsf4IaSZ93RRF1iBPCIkPPynJH7AdJRUYWf9ObLABI2Yd57PB2+UMVArMSfARY/R0gClyA t63hfAUMRTpZgaIIw69M/6BTsoYZ3MbjPIhyJaPLcMCZJFl+IvjOTPV9NdMujDcSyB+Utx v5MxeuumhvzxgWmSk3VjkU78jSx4zSkG+tb5MAv0TCpDFzHxTUMWgtnxNuvgc3+3Jjc4oO 1i0dhLvyMUrw/pUp7yF9lLfDDgJo5NDLYA3V6wfwnJXm5a8pCE7DCAgQH90dIAzEUCtvU+ P+7mk8xrcwlVpmygbbkosbiAAC7rQdJWB10br6BLiTclahOTPfCWrC6/miVq6Q== Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 854ADADA2; Thu, 17 Sep 2020 10:07:03 +0000 (UTC) From: Oliver Neukum To: penguin-kernel@i-love.sakura.ne.jp, bjorn@mork.no, linux-usb@vger.kernel.org Cc: Oliver Neukum Subject: [RFC 4/7] CDC-WDM: fix race reporting errors in flush Date: Thu, 17 Sep 2020 12:06:11 +0200 Message-Id: <20200917100614.1010-5-oneukum@suse.com> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20200917100614.1010-1-oneukum@suse.com> References: <20200917100614.1010-1-oneukum@suse.com> Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org In case a race was lost and multiple fds used, an error could be reported multiple times. To fix this a spinlock must be taken. Signed-off-by: Oliver Neukum --- drivers/usb/class/cdc-wdm.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c index eee19532e67e..930000b1d43b 100644 --- a/drivers/usb/class/cdc-wdm.c +++ b/drivers/usb/class/cdc-wdm.c @@ -610,10 +610,14 @@ static int wdm_flush(struct file *file, fl_owner_t id) return -EIO; if (rv < 0) return -EINTR; + + spin_lock_irq(&desc->iuspin); rv = desc->werr; + desc->werr = 0; + spin_unlock_irq(&desc->iuspin); + if (rv < 0) - dev_err(&desc->intf->dev, "Error in flush path: %d\n", - rv); + dev_err(&desc->intf->dev, "Error in flush path: %d\n", rv); return usb_translate_errors(rv); }