From patchwork Fri Jun 10 12:17:57 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Linyu Yuan X-Patchwork-Id: 581394 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 6E4E8C43334 for ; Fri, 10 Jun 2022 12:18:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348990AbiFJMSQ (ORCPT ); Fri, 10 Jun 2022 08:18:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34140 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348865AbiFJMSM (ORCPT ); Fri, 10 Jun 2022 08:18:12 -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 2DFC7273912; Fri, 10 Jun 2022 05:18:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; i=@quicinc.com; q=dns/txt; s=qcdkim; t=1654863489; x=1686399489; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=QY+MoqRaocvrkDjvRhxlH1r4zKQeIIoc0IvvWA1YDiE=; b=HOE6eLJBBPHY6/eu0BBXdeiB36lUPk5AWzVB0AzdQhApzM/zzfF7jmaK +n0k+8IsdDZqPty819UtMvM4MfWR9EOYO/96VUHjQaOsUfRMZ5E49ArgW nNlwCcDhQ/2R9UIELNZ89toJMFZwTxCYxZsRj6EKDVuSVrzyjMuzH0E5c w=; Received: from unknown (HELO ironmsg-SD-alpha.qualcomm.com) ([10.53.140.30]) by alexa-out-sd-02.qualcomm.com with ESMTP; 10 Jun 2022 05:18:08 -0700 X-QCInternal: smtphost Received: from nasanex01c.na.qualcomm.com ([10.47.97.222]) by ironmsg-SD-alpha.qualcomm.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Jun 2022 05:18:08 -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; Fri, 10 Jun 2022 05:18:08 -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; Fri, 10 Jun 2022 05:18:05 -0700 From: Linyu Yuan To: Felipe Balbi , Greg Kroah-Hartman CC: , , Jack Pham , Michael Wu , "John Keeping" , Linyu Yuan Subject: [PATCH v5 1/2] usb: gadget: f_fs: change ep->status safe in ffs_epfile_io() Date: Fri, 10 Jun 2022 20:17:57 +0800 Message-ID: <1654863478-26228-2-git-send-email-quic_linyyuan@quicinc.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1654863478-26228-1-git-send-email-quic_linyyuan@quicinc.com> References: <1654863478-26228-1-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. Cc: # 5.15 Reported-by: Michael Wu Tested-by: Michael Wu Reviewed-by: John Keeping Signed-off-by: Linyu Yuan --- v2: correct interrupted assignment v3: add Reviewed-by and Reported-by v4: add Tetsed-by from Michael Wu, remove one empty line cc stable kernel v5: change ?: to if/else format drivers/usb/gadget/function/f_fs.c | 34 +++++++++++++++++++--------------- 1 file changed, 19 insertions(+), 15 deletions(-) diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index 4585ee3..e1fcd8b 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 +708,15 @@ 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); - } + if (req->status) + io_data->status = req->status; + else + io_data->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 +1054,6 @@ 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 +1069,8 @@ 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 +1079,7 @@ 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 +1087,17 @@ 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;