From mboxrd@z Thu Jan 1 00:00:00 1970 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=-6.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 13953C433E2 for ; Thu, 4 Jun 2020 15:47:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E600C2065C for ; Thu, 4 Jun 2020 15:47:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="XtFOq2IU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729571AbgFDPry (ORCPT ); Thu, 4 Jun 2020 11:47:54 -0400 Received: from m43-7.mailgun.net ([69.72.43.7]:44939 "EHLO m43-7.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729402AbgFDPrx (ORCPT ); Thu, 4 Jun 2020 11:47:53 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1591285672; h=Message-ID: References: In-Reply-To: Subject: Cc: To: From: Date: Content-Transfer-Encoding: Content-Type: MIME-Version: Sender; bh=h8D99gB6H9xf8a2OzankwEOfZlf6igNRbDESI7T7Zx4=; b=XtFOq2IUE+T2QS8cZmXuPnG9fHI+cj/tEsOxfJFPVX4K47TS8/pAd9FIXEr8GdXHeEeYe27r 3THKiPOdUwIFLN0nOpA+++3+3cxwjQexts/aZjeAoOmVQPWe02+uR9/7BJZ9fTEXyv6uWy+Z w4f8CTgKn64sUKLLgwCL9AUKXNc= X-Mailgun-Sending-Ip: 69.72.43.7 X-Mailgun-Sid: WyI0MWYwYSIsICJsaW51eC1rZXJuZWxAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n05.prod.us-east-1.postgun.com with SMTP id 5ed9179ec0031c71c2a191d8 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Thu, 04 Jun 2020 15:47:42 GMT Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 8BE02C43387; Thu, 4 Jun 2020 15:47:37 +0000 (UTC) Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: bgodavar) by smtp.codeaurora.org (Postfix) with ESMTPSA id CFF16C433CA; Thu, 4 Jun 2020 15:47:36 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Thu, 04 Jun 2020 21:17:36 +0530 From: bgodavar@codeaurora.org To: Venkata Lakshmi Narayana Gubba Cc: marcel@holtmann.org, johan.hedberg@gmail.com, mka@chromium.org, linux-kernel@vger.kernel.org, linux-bluetooth@vger.kernel.org, robh@kernel.org, hemantg@codeaurora.org, linux-arm-msm@vger.kernel.org, tientzu@chromium.org, seanpaul@chromium.org, rjliao@codeaurora.org, yshavit@google.com, abhishekpandit@chromium.org Subject: Re: [PATCH v1] Bluetooth: hci_qca: Fix double free during SSR timeout In-Reply-To: <1591279032-7527-1-git-send-email-gubbaven@codeaurora.org> References: <1591279032-7527-1-git-send-email-gubbaven@codeaurora.org> Message-ID: <9baddcafef3c1ecad1f968e3adaf3201@codeaurora.org> X-Sender: bgodavar@codeaurora.org User-Agent: Roundcube Webmail/1.3.9 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020-06-04 19:27, Venkata Lakshmi Narayana Gubba wrote: > Due to race conditions between qca_hw_error and qca_controller_memdump > during SSR timeout,the same pointer is freed twice. Which results to > double free error. Now a lock is acquired while SSR state moved to > timeout. > > Signed-off-by: Venkata Lakshmi Narayana Gubba > --- > drivers/bluetooth/hci_qca.c | 19 ++++++++++++++----- > 1 file changed, 14 insertions(+), 5 deletions(-) > > diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c > index 836949d..9110775 100644 > --- a/drivers/bluetooth/hci_qca.c > +++ b/drivers/bluetooth/hci_qca.c > @@ -983,8 +983,11 @@ static void qca_controller_memdump(struct > work_struct *work) > while ((skb = skb_dequeue(&qca->rx_memdump_q))) { > > mutex_lock(&qca->hci_memdump_lock); > - /* Skip processing the received packets if timeout detected. */ > - if (qca->memdump_state == QCA_MEMDUMP_TIMEOUT) { > + /* Skip processing the received packets if timeout detected > + * or memdump collection completed. > + */ > + if (qca->memdump_state == QCA_MEMDUMP_TIMEOUT || > + qca->memdump_state == QCA_MEMDUMP_COLLECTED) { > mutex_unlock(&qca->hci_memdump_lock); > return; > } > @@ -1485,7 +1488,7 @@ static void qca_hw_error(struct hci_dev *hdev, u8 > code) > { > struct hci_uart *hu = hci_get_drvdata(hdev); > struct qca_data *qca = hu->priv; > - struct qca_memdump_data *qca_memdump = qca->qca_memdump; > + struct qca_memdump_data *qca_memdump = NULL; > char *memdump_buf = NULL; > > set_bit(QCA_HW_ERROR_EVENT, &qca->flags); > @@ -1509,9 +1512,10 @@ static void qca_hw_error(struct hci_dev *hdev, > u8 code) > qca_wait_for_dump_collection(hdev); > } > > + mutex_lock(&qca->hci_memdump_lock); > if (qca->memdump_state != QCA_MEMDUMP_COLLECTED) { > bt_dev_err(hu->hdev, "clearing allocated memory due to memdump > timeout"); > - mutex_lock(&qca->hci_memdump_lock); > + qca_memdump = qca->qca_memdump; > if (qca_memdump) > memdump_buf = qca_memdump->memdump_buf_head; > vfree(memdump_buf); > @@ -1520,8 +1524,13 @@ static void qca_hw_error(struct hci_dev *hdev, > u8 code) > qca->memdump_state = QCA_MEMDUMP_TIMEOUT; > cancel_delayed_work(&qca->ctrl_memdump_timeout); > skb_queue_purge(&qca->rx_memdump_q); > - mutex_unlock(&qca->hci_memdump_lock); > + } > + mutex_unlock(&qca->hci_memdump_lock); > + > + if (qca->memdump_state == QCA_MEMDUMP_TIMEOUT || > + qca->memdump_state == QCA_MEMDUMP_COLLECTED) { > cancel_work_sync(&qca->ctrl_memdump_evt); > + skb_queue_purge(&qca->rx_memdump_q); > } > > clear_bit(QCA_HW_ERROR_EVENT, &qca->flags); Reviewed-by: Balakrishna Godavarthi