From a4b035a6fa29ac347857d9ca20df28d425a4e566 Mon Sep 17 00:00:00 2001 From: Mathias Nyman Date: Thu, 3 May 2018 17:30:07 +0300 Subject: [PATCH] xhci: Fix use-after-free in xhci_free_virt_device BugLink: http://bugs.launchpad.net/bugs/1778759 commit 44a182b9d17765514fa2b1cc911e4e65134eef93 upstream. KASAN found a use-after-free in xhci_free_virt_device+0x33b/0x38e where xhci_free_virt_device() sets slot id to 0 if udev exists: if (dev->udev && dev->udev->slot_id) dev->udev->slot_id = 0; dev->udev will be true even if udev is freed because dev->udev is not set to NULL. set dev->udev pointer to NULL in xhci_free_dev() The original patch went to stable so this fix needs to be applied there as well. Fixes: a400efe455f7 ("xhci: zero usb device slot_id member when disabling and freeing a xhci slot") Cc: Reported-by: Guenter Roeck Reviewed-by: Guenter Roeck Tested-by: Guenter Roeck Signed-off-by: Mathias Nyman Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman Signed-off-by: Kamal Mostafa Signed-off-by: Khalid Elmously --- drivers/usb/host/xhci.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 128931a8268a..d5dee03c2ce9 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -3564,6 +3564,7 @@ static void xhci_free_dev(struct usb_hcd *hcd, struct usb_device *udev) del_timer_sync(&virt_dev->eps[i].stop_cmd_timer); } xhci_debugfs_remove_slot(xhci, udev->slot_id); + virt_dev->udev = NULL; ret = xhci_disable_slot(xhci, udev->slot_id); if (ret) xhci_free_virt_device(xhci, udev->slot_id); -- 2.39.2