From patchwork Wed Jun 1 04:15:15 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Linyu Yuan X-Patchwork-Id: 12866334 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 D0BBCC433F5 for ; Wed, 1 Jun 2022 04:15:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232401AbiFAEPy (ORCPT ); Wed, 1 Jun 2022 00:15:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50216 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232248AbiFAEPw (ORCPT ); Wed, 1 Jun 2022 00:15:52 -0400 Received: from alexa-out-sd-02.qualcomm.com (alexa-out-sd-02.qualcomm.com [199.106.114.39]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B57B39CF59 for ; Tue, 31 May 2022 21:15:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; i=@quicinc.com; q=dns/txt; s=qcdkim; t=1654056950; x=1685592950; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=5w/J1i9kiKudxoaJVstx04U9i1tM5D6vGhwOlKflHk0=; b=fOXIg633hE8mS/mzagSsYM9OJ2yfeQJ0u0W8EHMeiw4w9izYm0A1uqKW gw6Y0YSDe7/AvSbmN94FiDNUeCxAriLuoanmGfPXN7Lp++sKsR7kW1Qqg WkXgWEB8mzSA8DHFFCHzD5dqGzUq45OAK+impjmV4YTho4rBpD+lUXE+N M=; Received: from unknown (HELO ironmsg02-sd.qualcomm.com) ([10.53.140.142]) by alexa-out-sd-02.qualcomm.com with ESMTP; 31 May 2022 21:15:50 -0700 X-QCInternal: smtphost Received: from nasanex01c.na.qualcomm.com ([10.47.97.222]) by ironmsg02-sd.qualcomm.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 May 2022 21:15:50 -0700 Received: from nalasex01b.na.qualcomm.com (10.47.209.197) by nasanex01c.na.qualcomm.com (10.47.97.222) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.22; Tue, 31 May 2022 21:15:49 -0700 Received: from linyyuan-gv.qualcomm.com (10.80.80.8) by nalasex01b.na.qualcomm.com (10.47.209.197) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.22; Tue, 31 May 2022 21:15:48 -0700 From: Linyu Yuan To: Felipe Balbi , Greg Kroah-Hartman CC: , Michael Wu , "John Keeping" , Linyu Yuan Subject: [PATCH v3 1/2] usb: gadget: f_fs: change ep->status safe in ffs_epfile_io() Date: Wed, 1 Jun 2022 12:15:15 +0800 Message-ID: <1654056916-2062-2-git-send-email-quic_linyyuan@quicinc.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1654056916-2062-1-git-send-email-quic_linyyuan@quicinc.com> References: <1654056916-2062-1-git-send-email-quic_linyyuan@quicinc.com> MIME-Version: 1.0 X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01b.na.qualcomm.com (10.46.141.250) To nalasex01b.na.qualcomm.com (10.47.209.197) Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org If a task read/write data in blocking mode, it will wait the completion in ffs_epfile_io(), if function unbind occurs, ffs_func_unbind() will kfree ffs ep, once the task wake up, it still dereference the ffs ep to obtain the request status. Fix it by moving the request status to io_data which is stack-safe. Reported-by: Michael Wu Reviewed-by: John Keeping Signed-off-by: Linyu Yuan --- v2: correct interrupted assignment v3: add Reviewed-by and Reported-by drivers/usb/gadget/function/f_fs.c | 32 +++++++++++++++++--------------- 1 file changed, 17 insertions(+), 15 deletions(-) diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index 4585ee3..d4d8940 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -122,8 +122,6 @@ struct ffs_ep { struct usb_endpoint_descriptor *descs[3]; u8 num; - - int status; /* P: epfile->mutex */ }; struct ffs_epfile { @@ -227,6 +225,9 @@ struct ffs_io_data { bool use_sg; struct ffs_data *ffs; + + int status; + struct completion done; }; struct ffs_desc_helper { @@ -707,12 +708,12 @@ static const struct file_operations ffs_ep0_operations = { static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req) { + struct ffs_io_data *io_data = req->context; + ENTER(); - if (req->context) { - struct ffs_ep *ep = _ep->driver_data; - ep->status = req->status ? req->status : req->actual; - complete(req->context); - } + + io_data->status = req->status ? req->status : req->actual; + complete(&io_data->done); } static ssize_t ffs_copy_to_iter(void *data, int data_len, struct iov_iter *iter) @@ -1050,7 +1051,6 @@ static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data) WARN(1, "%s: data_len == -EINVAL\n", __func__); ret = -EINVAL; } else if (!io_data->aio) { - DECLARE_COMPLETION_ONSTACK(done); bool interrupted = false; req = ep->req; @@ -1066,7 +1066,8 @@ static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data) io_data->buf = data; - req->context = &done; + init_completion(&io_data->done); + req->context = io_data; req->complete = ffs_epfile_io_complete; ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC); @@ -1075,7 +1076,7 @@ static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data) spin_unlock_irq(&epfile->ffs->eps_lock); - if (wait_for_completion_interruptible(&done)) { + if (wait_for_completion_interruptible(&io_data->done)) { /* * To avoid race condition with ffs_epfile_io_complete, * dequeue the request first then check @@ -1083,17 +1084,18 @@ static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data) * condition with req->complete callback. */ usb_ep_dequeue(ep->ep, req); - wait_for_completion(&done); - interrupted = ep->status < 0; + wait_for_completion(&io_data->done); + interrupted = io_data->status < 0; } if (interrupted) ret = -EINTR; - else if (io_data->read && ep->status > 0) - ret = __ffs_epfile_read_data(epfile, data, ep->status, + else if (io_data->read && io_data->status > 0) + ret = __ffs_epfile_read_data(epfile, data, io_data->status, &io_data->data); else - ret = ep->status; + ret = io_data->status; + goto error_mutex; } else if (!(req = usb_ep_alloc_request(ep->ep, GFP_ATOMIC))) { ret = -ENOMEM;