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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 7406CC10F27 for ; Mon, 9 Mar 2020 15:27:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 57ABC21D7E for ; Mon, 9 Mar 2020 15:27:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726997AbgCIP1B (ORCPT ); Mon, 9 Mar 2020 11:27:01 -0400 Received: from unicorn.mansr.com ([81.2.72.234]:54684 "EHLO unicorn.mansr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726605AbgCIP1B (ORCPT ); Mon, 9 Mar 2020 11:27:01 -0400 Received: by unicorn.mansr.com (Postfix, from userid 51770) id 0741B15F11; Mon, 9 Mar 2020 15:26:59 +0000 (GMT) From: Mans Rullgard To: Bin Liu Cc: Greg Kroah-Hartman , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] usb: musb: fix crash with highmen PIO and usbmon Date: Mon, 9 Mar 2020 15:26:53 +0000 Message-Id: <20200309152653.29161-1-mans@mansr.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org When handling a PIO bulk transfer with highmem buffer, a temporary mapping is assigned to urb->transfer_buffer. After the transfer is complete, an invalid address is left behind in this pointer. This is not ordinarily a problem since nothing touches that buffer before the urb is released. However, when usbmon is active, usbmon_urb_complete() calls (indirectly) mon_bin_get_data() which does access the transfer buffer if it is set. To prevent an invalid memory access here, reset urb->tranfer_buffer to NULL when finished (musb_host_rx()), or do not set it at all (musb_host_tx()). Fixes: 8e8a55165469 ("usb: musb: host: Handle highmem in PIO mode") Signed-off-by: Mans Rullgard --- Changed in v2: - Do not set urb->transfer_buffer in musb_host_tx() --- drivers/usb/musb/musb_host.c | 17 +++++------------ 1 file changed, 5 insertions(+), 12 deletions(-) diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c index 1c813c37462a..8736f4251a22 100644 --- a/drivers/usb/musb/musb_host.c +++ b/drivers/usb/musb/musb_host.c @@ -1436,10 +1436,7 @@ void musb_host_tx(struct musb *musb, u8 epnum) * We need to map sg if the transfer_buffer is * NULL. */ - if (!urb->transfer_buffer) - qh->use_sg = true; - - if (qh->use_sg) { + if (!urb->transfer_buffer) { /* sg_miter_start is already done in musb_ep_program */ if (!sg_miter_next(&qh->sg_miter)) { dev_err(musb->controller, "error: sg list empty\n"); @@ -1447,9 +1444,8 @@ void musb_host_tx(struct musb *musb, u8 epnum) status = -EINVAL; goto done; } - urb->transfer_buffer = qh->sg_miter.addr; length = min_t(u32, length, qh->sg_miter.length); - musb_write_fifo(hw_ep, length, urb->transfer_buffer); + musb_write_fifo(hw_ep, length, qh->sg_miter.addr); qh->sg_miter.consumed = length; sg_miter_stop(&qh->sg_miter); } else { @@ -1458,11 +1454,6 @@ void musb_host_tx(struct musb *musb, u8 epnum) qh->segsize = length; - if (qh->use_sg) { - if (offset + length >= urb->transfer_buffer_length) - qh->use_sg = false; - } - musb_ep_select(mbase, epnum); musb_writew(epio, MUSB_TXCSR, MUSB_TXCSR_H_WZC_BITS | MUSB_TXCSR_TXPKTRDY); @@ -1977,8 +1968,10 @@ void musb_host_rx(struct musb *musb, u8 epnum) urb->actual_length += xfer_len; qh->offset += xfer_len; if (done) { - if (qh->use_sg) + if (qh->use_sg) { qh->use_sg = false; + urb->transfer_buffer = NULL; + } if (urb->status == -EINPROGRESS) urb->status = status; -- 2.25.1