diff mbox series

[v1] usb: hcd: Fix use after free in usb_hcd_pci_remove()

Message ID 20200814182218.71957-1-andriy.shevchenko@linux.intel.com (mailing list archive)
State Mainlined
Commit 7b2816dd293031b9dec476d7853c099dc2ec9172
Headers show
Series [v1] usb: hcd: Fix use after free in usb_hcd_pci_remove() | expand

Commit Message

Andy Shevchenko Aug. 14, 2020, 6:22 p.m. UTC 
On the removal stage we put a reference to the controller structure and
if it's not used anymore it gets freed, but later we try to dereference
a pointer to a member of that structure.

Copy necessary field to a temporary variable to avoid use after free.

Fixes: 306c54d0edb6 ("usb: hcd: Try MSI interrupts on PCI devices")
Reported-by: John Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/linux-usb/30a8c4ca-64c2-863b-cfcd-0970599c0ba3@huawei.com/
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/usb/core/hcd-pci.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/usb/core/hcd-pci.c b/drivers/usb/core/hcd-pci.c
index 4dc443aaef5c..ec0d6c50610c 100644
--- a/drivers/usb/core/hcd-pci.c
+++ b/drivers/usb/core/hcd-pci.c
@@ -315,11 +315,14 @@  EXPORT_SYMBOL_GPL(usb_hcd_pci_probe);
 void usb_hcd_pci_remove(struct pci_dev *dev)
 {
 	struct usb_hcd		*hcd;
+	int			hcd_driver_flags;
 
 	hcd = pci_get_drvdata(dev);
 	if (!hcd)
 		return;
 
+	hcd_driver_flags = hcd->driver->flags;
+
 	if (pci_dev_run_wake(dev))
 		pm_runtime_get_noresume(&dev->dev);
 
@@ -347,7 +350,7 @@  void usb_hcd_pci_remove(struct pci_dev *dev)
 		up_read(&companions_rwsem);
 	}
 	usb_put_hcd(hcd);
-	if ((hcd->driver->flags & HCD_MASK) < HCD_USB3)
+	if ((hcd_driver_flags & HCD_MASK) < HCD_USB3)
 		pci_free_irq_vectors(dev);
 	pci_disable_device(dev);
 }