From dff34ef879c5e73298443956a8b391311ba78d57 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Fri, 27 Mar 2026 11:52:05 +0100 Subject: [PATCH 1/2] mmc: vub300: fix NULL-deref on disconnect Make sure to deregister the controller before dropping the reference to the driver data on disconnect to avoid NULL-pointer dereferences or use-after-free. Fixes: 88095e7b473a ("mmc: Add new VUB300 USB-to-SD/SDIO/MMC driver") Cc: stable@vger.kernel.org # 3.0+ Signed-off-by: Johan Hovold Signed-off-by: Ulf Hansson --- drivers/mmc/host/vub300.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/mmc/host/vub300.c b/drivers/mmc/host/vub300.c index ff49d0770506..f173c7cf4e1a 100644 --- a/drivers/mmc/host/vub300.c +++ b/drivers/mmc/host/vub300.c @@ -2365,8 +2365,8 @@ static void vub300_disconnect(struct usb_interface *interface) usb_set_intfdata(interface, NULL); /* prevent more I/O from starting */ vub300->interface = NULL; - kref_put(&vub300->kref, vub300_delete); mmc_remove_host(mmc); + kref_put(&vub300->kref, vub300_delete); pr_info("USB vub300 remote SDIO host controller[%d]" " now disconnected", ifnum); return; From 8f4d20a710225ec7a565f6a0459862d3b1f32330 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Fri, 27 Mar 2026 11:52:06 +0100 Subject: [PATCH 2/2] 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: dcfdd698dc52 ("mmc: vub300: Use devm_mmc_alloc_host() helper") Cc: stable@vger.kernel.org # 6.17+ Cc: Binbin Zhou Signed-off-by: Johan Hovold Signed-off-by: Ulf Hansson --- drivers/mmc/host/vub300.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/drivers/mmc/host/vub300.c b/drivers/mmc/host/vub300.c index f173c7cf4e1a..3c9df27f9fa7 100644 --- a/drivers/mmc/host/vub300.c +++ b/drivers/mmc/host/vub300.c @@ -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