From patchwork Thu Sep 17 10:34:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oliver Neukum X-Patchwork-Id: 258515 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 12ED2C43461 for ; Thu, 17 Sep 2020 10:34:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B20412087D for ; Thu, 17 Sep 2020 10:34:47 +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="BSeWZ7Ix" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726410AbgIQKeo (ORCPT ); Thu, 17 Sep 2020 06:34:44 -0400 Received: from mx2.suse.de ([195.135.220.15]:33434 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726200AbgIQKen (ORCPT ); Thu, 17 Sep 2020 06:34:43 -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=1600338881; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc; bh=Bla3SM8EE1d/RcCyOYItOCiX01fGJhJlFQzYVwmBFsY=; b=BSeWZ7Ixq3m5mfygQX6JYLxL1Rx6k30zOmIu/ne8vdtLqV09q90xOhBR5ydRdjPtQPjbvK 0xwoA00NmUPJobPcKjh9QJO7KZHwObN2CSuutIMkTB/G8YyMKcKQL5xVgZizhPIfiGj+Q/ Gu1wuPWNYldk2RDhyNx+yohWjJ+QnYW3jaPogW/t8NbpqAAU58qtvfoAGE0YjMhgIr62Ex 3ODS18mwwT2GPBlFWl/ELTPXHUoxi8nrYQA/gYaAfOJrKM97RRlIoEYptjSmE8OkFgqF3J D3qzLAn6EuCahF37T9VJ8iHB0XIBk2Y/VVzmXGyDX7Fq1cJvlDR0YWjjYCZb3g== Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 53400ABC4; Thu, 17 Sep 2020 10:35:15 +0000 (UTC) From: Oliver Neukum To: gregKH@linuxfoundation.org, linux-usb@vger.kernel.org Cc: Oliver Neukum Subject: [PATCH] usblp: fix race between disconnect() and read() Date: Thu, 17 Sep 2020 12:34:27 +0200 Message-Id: <20200917103427.15740-1-oneukum@suse.com> X-Mailer: git-send-email 2.16.4 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org read() needs to check whether the device has been disconnected before it tries to talk to the device. Signed-off-by: Oliver Neukum Reported-by: syzbot+be5b5f86a162a6c281e6@syzkaller.appspotmail.com --- drivers/usb/class/usblp.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/usb/class/usblp.c b/drivers/usb/class/usblp.c index 084c48c5848f..67cbd42421be 100644 --- a/drivers/usb/class/usblp.c +++ b/drivers/usb/class/usblp.c @@ -827,6 +827,11 @@ static ssize_t usblp_read(struct file *file, char __user *buffer, size_t len, lo if (rv < 0) return rv; + if (!usblp->present) { + count = -ENODEV; + goto done; + } + if ((avail = usblp->rstatus) < 0) { printk(KERN_ERR "usblp%d: error %d reading from printer\n", usblp->minor, (int)avail);