USB: fix linked-list corruption in rh_call_control()

Using KASAN, Dmitry found a bug in the rh_call_control() routine: If
buffer allocation fails, the routine returns immediately without
unlinking its URB from the control endpoint, eventually leading to
linked-list corruption.

This patch fixes the problem by jumping to the end of the routine
(where the URB is unlinked) when an allocation failure occurs.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-and-tested-by: Dmitry Vyukov <dvyukov@google.com>
CC: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 612fab6e54fb84f2d84372d202c77823fc3be921..79bdca5cb9c7ae8f01b1f4a25c7ceacd9c716e2c 100644 (file)
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -520,8 +520,10 @@ static int rh_call_control (struct usb_hcd *hcd, struct urb *urb)
         */
        tbuf_size =  max_t(u16, sizeof(struct usb_hub_descriptor), wLength);
        tbuf = kzalloc(tbuf_size, GFP_KERNEL);
-       if (!tbuf)
-               return -ENOMEM;
+       if (!tbuf) {
+               status = -ENOMEM;
+               goto err_alloc;
+       }
 
        bufp = tbuf;
 
@@ -734,6 +736,7 @@ error:
        }
 
        kfree(tbuf);
+ err_alloc:
 
        /* any errors get returned through the urb completion */
        spin_lock_irq(&hcd_root_hub_lock);