From patchwork Sat Feb 11 12:17:38 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Prashanth K X-Patchwork-Id: 13137046 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D95FDC636CC for ; Sat, 11 Feb 2023 12:18:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230027AbjBKMSW (ORCPT ); Sat, 11 Feb 2023 07:18:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46276 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229793AbjBKMSD (ORCPT ); Sat, 11 Feb 2023 07:18:03 -0500 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 87F29241DA; Sat, 11 Feb 2023 04:18:02 -0800 (PST) Received: from pps.filterd (m0279872.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 31BBbgrw019114; Sat, 11 Feb 2023 12:17:57 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=from : to : cc : subject : date : message-id : mime-version : content-type; s=qcppdkim1; bh=5h6MzoWQiCUa7cJYpAjuWIpHOhmwTSRHsB1DoYu9mV0=; b=KElPFrFyL/WwdpGy8645TdrL9ZdnhcxUoV0gWU1Z2C8AZo81BwLuIps6svbVlFHpVmtA ZpCV0d3YWn5yx6GzsBT6qTr5+LgojgcnTzAEbGOQLVm07FXH8IyQFZ7n/NWiwstPa2GS eR0QUGs0tdd5PAjIZbJViw/FWL2XkRyFOKo1tvYkdIkWx7wH1iB7TedLx98lDVcgyoXV gK+T4inRLkDd1davNoLfIz/avXTt97CODq3Hl37Q+nDyiedUGUQien+YmMwPr6IPh7cm 4szwgDCQ4SrBbJQvz3BL9gGhicBKyhv1TRLC681Pd+LeMfL37nJy0AzGMVRXMDZhSjMf hg== Received: from nalasppmta04.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3np3derns7-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sat, 11 Feb 2023 12:17:56 +0000 Received: from nalasex01a.na.qualcomm.com (nalasex01a.na.qualcomm.com [10.47.209.196]) by NALASPPMTA04.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 31BCHt39032237 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sat, 11 Feb 2023 12:17:55 GMT Received: from hu-prashk-hyd.qualcomm.com (10.80.80.8) by nalasex01a.na.qualcomm.com (10.47.209.196) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.36; Sat, 11 Feb 2023 04:17:52 -0800 From: Prashanth K To: Greg Kroah-Hartman , Alan Stern , Christophe JAILLET , Xiu Jianfeng CC: Pratham Pratap , Jack Pham , , , Prashanth K Subject: [PATCH v2] usb: gadget: u_serial: Add null pointer check in gserial_resume Date: Sat, 11 Feb 2023 17:47:38 +0530 Message-ID: <1676117858-32157-1-git-send-email-quic_prashk@quicinc.com> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01b.na.qualcomm.com (10.46.141.250) To nalasex01a.na.qualcomm.com (10.47.209.196) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-GUID: SY-UZA_tNDGrO_D4R37iZS2MxnYPrHtC X-Proofpoint-ORIG-GUID: SY-UZA_tNDGrO_D4R37iZS2MxnYPrHtC X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.219,Aquarius:18.0.930,Hydra:6.0.562,FMLib:17.11.170.22 definitions=2023-02-11_06,2023-02-09_03,2023-02-09_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 mlxscore=0 clxscore=1015 adultscore=0 mlxlogscore=832 malwarescore=0 phishscore=0 lowpriorityscore=0 bulkscore=0 priorityscore=1501 impostorscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2212070000 definitions=main-2302110111 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Consider a case where gserial_disconnect has already cleared gser->ioport. And if a wakeup interrupt triggers afterwards, gserial_resume gets called, which will lead to accessing of gser->ioport and thus causing null pointer dereference.Add a null pointer check to prevent this. Added a static spinlock to prevent gser->ioport from becoming null after the newly added check. Fixes: aba3a8d01d62 ("usb: gadget: u_serial: add suspend resume callbacks") Signed-off-by: Prashanth K --- v2: Added static spinlock and fixed Fixes tag. drivers/usb/gadget/function/u_serial.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/drivers/usb/gadget/function/u_serial.c b/drivers/usb/gadget/function/u_serial.c index 840626e..9ced0fa 100644 --- a/drivers/usb/gadget/function/u_serial.c +++ b/drivers/usb/gadget/function/u_serial.c @@ -82,6 +82,8 @@ #define WRITE_BUF_SIZE 8192 /* TX only */ #define GS_CONSOLE_BUF_SIZE 8192 +static DEFINE_SPINLOCK(serial_port_lock); + /* console info */ struct gs_console { struct console console; @@ -1370,11 +1372,13 @@ EXPORT_SYMBOL_GPL(gserial_connect); void gserial_disconnect(struct gserial *gser) { struct gs_port *port = gser->ioport; - unsigned long flags; + unsigned long flags, serial_flag; if (!port) return; + spin_lock_irqsave(&serial_port_lock, serial_flag); + /* tell the TTY glue not to do I/O here any more */ spin_lock_irqsave(&port->port_lock, flags); @@ -1392,6 +1396,7 @@ void gserial_disconnect(struct gserial *gser) } port->suspended = false; spin_unlock_irqrestore(&port->port_lock, flags); + spin_unlock_irqrestore(&serial_port_lock, serial_flag); /* disable endpoints, aborting down any active I/O */ usb_ep_disable(gser->out); @@ -1426,9 +1431,16 @@ EXPORT_SYMBOL_GPL(gserial_suspend); void gserial_resume(struct gserial *gser) { struct gs_port *port = gser->ioport; - unsigned long flags; + unsigned long flags, serial_flag; + + spin_lock_irqsave(&serial_port_lock, serial_flag); + if (!port) { + spin_unlock_irqrestore(&serial_port_lock, serial_flag); + return; + } spin_lock_irqsave(&port->port_lock, flags); + spin_unlock_irqrestore(&serial_port_lock, serial_flag); port->suspended = false; if (!port->start_delayed) { spin_unlock_irqrestore(&port->port_lock, flags);