[PATCH 6.12.y 1/3] mmc: vub300: fix use-after-free on disconnect

[Sasha Levin <sashal@kernel.org>]

From: Johan Hovold <johan@kernel.org>

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: dcfdd698dc52 ("mmc: vub300: Use devm_mmc_alloc_host() helper")
Cc: stable@vger.kernel.org # 6.17+
Cc: Binbin Zhou <zhoubinbin@loongson.cn>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
(cherry picked from commit 8f4d20a710225ec7a565f6a0459862d3b1f32330)
---
 drivers/mmc/host/vub300.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/mmc/host/vub300.c b/drivers/mmc/host/vub300.c
index 35393f534de2bd..b39978357aab28 100644
--- a/drivers/mmc/host/vub300.c
+++ b/drivers/mmc/host/vub300.c
@@ -2279,7 +2279,7 @@ 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 error5;
+		goto err_free_host;
 	}
 	retval =
 		usb_control_msg(vub300->udev, usb_rcvctrlpipe(vub300->udev, 0),
@@ -2288,14 +2288,14 @@ static int vub300_probe(struct usb_interface *interface,
 				0x0000, 0x0000, &vub300->hc_info,
 				sizeof(vub300->hc_info), 1000);
 	if (retval < 0)
-		goto error5;
+		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 error5;
+		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",
@@ -2310,7 +2310,7 @@ static int vub300_probe(struct usb_interface *interface,
 				0x0000, 0x0000, &vub300->system_port_status,
 				sizeof(vub300->system_port_status), 1000);
 	if (retval < 0) {
-		goto error5;
+		goto err_free_host;
 	} else if (sizeof(vub300->system_port_status) == retval) {
 		vub300->card_present =
 			(0x0001 & vub300->system_port_status.port_flags) ? 1 : 0;
@@ -2318,7 +2318,7 @@ static int vub300_probe(struct usb_interface *interface,
 			(0x0010 & vub300->system_port_status.port_flags) ? 1 : 0;
 	} else {
 		retval = -EINVAL;
-		goto error5;
+		goto err_free_host;
 	}
 	usb_set_intfdata(interface, vub300);
 	INIT_DELAYED_WORK(&vub300->pollwork, vub300_pollwork_thread);
@@ -2348,7 +2348,7 @@ static int vub300_probe(struct usb_interface *interface,
 	return 0;
 error6:
 	del_timer_sync(&vub300->inactivity_timer);
-error5:
+err_free_host:
 	mmc_free_host(mmc);
 	/*
 	 * and hence also frees vub300
-- 
2.53.0