From patchwork Tue Sep 22 11:21:23 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oliver Neukum X-Patchwork-Id: 297542 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=-12.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, 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 B740AC2D0E2 for ; Tue, 22 Sep 2020 11:21:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 65BEF23A1B for ; Tue, 22 Sep 2020 11:21:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="CNKQQq1x" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726554AbgIVLVw (ORCPT ); Tue, 22 Sep 2020 07:21:52 -0400 Received: from mx2.suse.de ([195.135.220.15]:37386 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726513AbgIVLVv (ORCPT ); Tue, 22 Sep 2020 07:21:51 -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=susede1; t=1600773710; 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=3J4awFmP6XNuAxKP8nvMUO9NLGMgKpv8n8B5oWGFW6o=; b=CNKQQq1xqYemNXHfqeYqgMdBtlv0veoUgumCXuQaxsuJlQPccmRyEvHT4MZ+p/qd+ZnE6r apkcNBYbQWcWolCDLyacbX3Io8PtWwKPiyye94O1GLpUUk3Nw8bUXHEIVLLH17aiYxxR7h kvzsTxtI3Wfcg6D1kj/XqYZDOR9Uw5w= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 68165AE19; Tue, 22 Sep 2020 11:22:27 +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: Tue, 22 Sep 2020 13:21:23 +0200 Message-Id: <20200922112126.16919-5-oneukum@suse.com> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20200922112126.16919-1-oneukum@suse.com> References: <20200922112126.16919-1-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 | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c index 1ca2c85a977d..5fb855404403 100644 --- a/drivers/usb/class/cdc-wdm.c +++ b/drivers/usb/class/cdc-wdm.c @@ -613,7 +613,10 @@ static int wdm_flush(struct file *file, fl_owner_t id) if (!rv) return -EIO; + spin_lock_irq(&desc->iuspin); rv = desc->werr; + desc->werr = 0; + spin_unlock_irq(&desc->iuspin); return usb_translate_errors(rv); }