From patchwork Wed Jun 1 04:15:16 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Linyu Yuan X-Patchwork-Id: 12866335 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 7D0D4C433EF for ; Wed, 1 Jun 2022 04:16:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232456AbiFAEQA (ORCPT ); Wed, 1 Jun 2022 00:16:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50272 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232248AbiFAEP7 (ORCPT ); Wed, 1 Jun 2022 00:15:59 -0400 Received: from alexa-out.qualcomm.com (alexa-out.qualcomm.com [129.46.98.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8FAC59CF64 for ; Tue, 31 May 2022 21:15:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; i=@quicinc.com; q=dns/txt; s=qcdkim; t=1654056958; x=1685592958; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=nNCOA0Xb/Vydyork6QOAfUO2Y2Gkm1AhMAj+H0m/n/I=; b=E/5Y8I0FCLwSw3cSOvZUmVtSToTOcC9S751XPSb8ltpmlu26i/MYck+e Rx6euVysKnM3sRlFCOf3XTXsHOIwws7v9jhpuAQEO5liIrCSOhkmMD2z8 8XnT+uMzEeXA5Biqu6QMUGdWa1aGCCdH0L5FsTzY3AvW5Hq0Ou65BOhKR g=; Received: from ironmsg-lv-alpha.qualcomm.com ([10.47.202.13]) by alexa-out.qualcomm.com with ESMTP; 31 May 2022 21:15:58 -0700 X-QCInternal: smtphost Received: from nasanex01c.na.qualcomm.com ([10.47.97.222]) by ironmsg-lv-alpha.qualcomm.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 May 2022 21:15:57 -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 21:15:57 -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 21:15:56 -0700 From: Linyu Yuan To: Felipe Balbi , Greg Kroah-Hartman CC: , Michael Wu , "John Keeping" , Linyu Yuan Subject: [PATCH v3 2/2] usb: gadget: f_fs: change ep->ep safe in ffs_epfile_io() Date: Wed, 1 Jun 2022 12:15:16 +0800 Message-ID: <1654056916-2062-3-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 In ffs_epfile_io(), when read/write data in blocking mode, it will wait the completion in interruptible mode, if task receive a signal, it will terminate the wait, at same time, if function unbind occurs, ffs_func_unbind() will kfree all eps, ffs_epfile_io() still try to dequeue request by dereferencing ep which may become invalid. Fix it by add ep spinlock and will not dereference ep if it is not valid. Reported-by: Michael Wu Reviewed-by: John Keeping Signed-off-by: Linyu Yuan Tested-by: Michael Wu --- v2: add Reviewed-by from John keeping v3: add Reported-by from Michael Wu drivers/usb/gadget/function/f_fs.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index d4d8940..9bf9287 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -1077,6 +1077,11 @@ 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(&io_data->done)) { + spin_lock_irq(&epfile->ffs->eps_lock); + if (epfile->ep != ep) { + ret = -ESHUTDOWN; + goto error_lock; + } /* * To avoid race condition with ffs_epfile_io_complete, * dequeue the request first then check @@ -1084,6 +1089,7 @@ 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); + spin_unlock_irq(&epfile->ffs->eps_lock); wait_for_completion(&io_data->done); interrupted = io_data->status < 0; }