Commit 52974d94 authored by Mans Rullgard's avatar Mans Rullgard Committed by Greg Kroah-Hartman
Browse files

usb: musb: fix crash with highmen PIO and usbmon 



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->transfer_buffer to NULL when finished (musb_host_rx()), or do not
set it at all (musb_host_tx()).

Fixes: 8e8a5516 ("usb: musb: host: Handle highmem in PIO mode")
Signed-off-by: default avatarMans Rullgard <mans@mansr.com>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarBin Liu <b-liu@ti.com>
Link: https://lore.kernel.org/r/20200316211136.2274-8-b-liu@ti.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent e72838d4

drivers/usb/musb/musb_host.c

+5 −12
Original line number Diff line number Diff line
@@ -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;