From patchwork Tue Sep 22 10:13:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oliver Neukum X-Patchwork-Id: 11792051 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 771016CB for ; Tue, 22 Sep 2020 10:13:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 518CB238D7 for ; Tue, 22 Sep 2020 10:13:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="It8rTNJz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726509AbgIVKNz (ORCPT ); Tue, 22 Sep 2020 06:13:55 -0400 Received: from mx2.suse.de ([195.135.220.15]:57352 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726605AbgIVKNy (ORCPT ); Tue, 22 Sep 2020 06:13:54 -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=1600769633; 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=It8rTNJzce86wU+tUp1PnTI34w/VBTqETGCQ5NlyRgXO+iJ19TJ70cVcrcgPpGp3HiOgyv b1rtjSZ3TRFCn/huAi2WD3WUwhgQlAXMogv27Gy7hO9i34oROqFYAfwiWQ25LobEzyvWtE uXVOsZgtZiPBNklTTkSd0uNHDLIDYgM= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 1BDF0ABD2; Tue, 22 Sep 2020 10:14:30 +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 4/6] CDC-WDM: fix race reporting errors in flush Date: Tue, 22 Sep 2020 12:13:27 +0200 Message-Id: <20200922101329.14801-5-oneukum@suse.com> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20200922101329.14801-1-oneukum@suse.com> References: <20200922101329.14801-1-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); }