Commit 8f4d20a7 authored by Johan Hovold's avatar Johan Hovold Committed by Ulf Hansson
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mmc: vub300: fix use-after-free on disconnect 



The vub300 driver maintains an explicit reference count for the
controller and its driver data and the last reference can in theory be
dropped after the driver has been unbound.

This specifically means that the controller allocation must not be
device managed as that can lead to use-after-free.

Note that the lifetime is currently also incorrectly tied the parent USB
device rather than interface, which can lead to memory leaks if the
driver is unbound without its device being physically disconnected (e.g.
on probe deferral).

Fix both issues by reverting to non-managed allocation of the controller.

Fixes: dcfdd698 ("mmc: vub300: Use devm_mmc_alloc_host() helper")
Cc: stable@vger.kernel.org # 6.17+
Cc: Binbin Zhou <zhoubinbin@loongson.cn>
Signed-off-by: default avatarJohan Hovold <johan@kernel.org>
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent dff34ef8

drivers/mmc/host/vub300.c

+11 −6
Original line number Diff line number Diff line
@@ -369,11 +369,14 @@ struct vub300_mmc_host { 
static void vub300_delete(struct kref *kref)

{				/* kref callback - softirq */

	struct vub300_mmc_host *vub300 = kref_to_vub300_mmc_host(kref);

	struct mmc_host *mmc = vub300->mmc;



	usb_free_urb(vub300->command_out_urb);

	vub300->command_out_urb = NULL;

	usb_free_urb(vub300->command_res_urb);

	vub300->command_res_urb = NULL;

	usb_put_dev(vub300->udev);

	mmc_free_host(mmc);

	/*

	 * and hence also frees vub300

	 * which is contained at the end of struct mmc
@@ -2112,7 +2115,7 @@ static int vub300_probe(struct usb_interface *interface, 
		goto error1;

	}

	/* this also allocates memory for our VUB300 mmc host device */

	mmc = devm_mmc_alloc_host(&udev->dev, sizeof(*vub300));

	mmc = mmc_alloc_host(sizeof(*vub300), &udev->dev);

	if (!mmc) {

		retval = -ENOMEM;

		dev_err(&udev->dev, "not enough memory for the mmc_host\n");
@@ -2269,7 +2272,7 @@ static int vub300_probe(struct usb_interface *interface, 
		dev_err(&vub300->udev->dev,

		    "Could not find two sets of bulk-in/out endpoint pairs\n");

		retval = -EINVAL;

		goto error4;

		goto err_free_host;

	}

	retval =

		usb_control_msg(vub300->udev, usb_rcvctrlpipe(vub300->udev, 0),
@@ -2278,14 +2281,14 @@ static int vub300_probe(struct usb_interface *interface, 
				0x0000, 0x0000, &vub300->hc_info,

				sizeof(vub300->hc_info), 1000);

	if (retval < 0)

		goto error4;

		goto err_free_host;

	retval =

		usb_control_msg(vub300->udev, usb_sndctrlpipe(vub300->udev, 0),

				SET_ROM_WAIT_STATES,

				USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,

				firmware_rom_wait_states, 0x0000, NULL, 0, 1000);

	if (retval < 0)

		goto error4;

		goto err_free_host;

	dev_info(&vub300->udev->dev,

		 "operating_mode = %s %s %d MHz %s %d byte USB packets\n",

		 (mmc->caps & MMC_CAP_SDIO_IRQ) ? "IRQs" : "POLL",
@@ -2300,7 +2303,7 @@ static int vub300_probe(struct usb_interface *interface, 
				0x0000, 0x0000, &vub300->system_port_status,

				sizeof(vub300->system_port_status), 1000);

	if (retval < 0) {

		goto error4;

		goto err_free_host;

	} else if (sizeof(vub300->system_port_status) == retval) {

		vub300->card_present =

			(0x0001 & vub300->system_port_status.port_flags) ? 1 : 0;
@@ -2308,7 +2311,7 @@ static int vub300_probe(struct usb_interface *interface, 
			(0x0010 & vub300->system_port_status.port_flags) ? 1 : 0;

	} else {

		retval = -EINVAL;

		goto error4;

		goto err_free_host;

	}

	usb_set_intfdata(interface, vub300);

	INIT_DELAYED_WORK(&vub300->pollwork, vub300_pollwork_thread);
@@ -2338,6 +2341,8 @@ static int vub300_probe(struct usb_interface *interface, 
	return 0;

error6:

	timer_delete_sync(&vub300->inactivity_timer);

err_free_host:

	mmc_free_host(mmc);

	/*

	 * and hence also frees vub300

	 * which is contained at the end of struct mmc