From patchwork Mon Sep 21 11:20:49 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oliver Neukum X-Patchwork-Id: 11789369 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2D31A6CA for ; Mon, 21 Sep 2020 11:21:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 12ABF20EDD for ; Mon, 21 Sep 2020 11:21:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="VV8GTBfG" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726632AbgIULVR (ORCPT ); Mon, 21 Sep 2020 07:21:17 -0400 Received: from mx2.suse.de ([195.135.220.15]:58124 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726627AbgIULVQ (ORCPT ); Mon, 21 Sep 2020 07:21:16 -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=1600687275; 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=dPYL0e0Ftt9dWXB+VlV5J7hKo86XPX/rxVVpKU2I0Q4=; b=VV8GTBfGPLCUMpAhc3C2w1Nzrm+lheD729/iQ47fsmTwzySAheQRfOX898g2ds2Wd6K3yS 1tH8HxjpnKAWlqhTwg/VspIMJKKJ5qODGYb8R+QB9SPOoIPgLqYKy5Che1wu9p6MkC/Nzh CkDpYu7PnTckxm1TIKcYTtoEPV1tnYY= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 9F3D9B207; Mon, 21 Sep 2020 11:21:51 +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 5/8] CDC-WDM: fix race reporting errors in flush Date: Mon, 21 Sep 2020 13:20:49 +0200 Message-Id: <20200921112052.27943-6-oneukum@suse.com> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20200921112052.27943-1-oneukum@suse.com> References: <20200921112052.27943-1-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 40661b9f6775..89929f6438e3 100644 --- a/drivers/usb/class/cdc-wdm.c +++ b/drivers/usb/class/cdc-wdm.c @@ -614,8 +614,11 @@ 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); return usb_translate_errors(rv); }