Commit eac3ab3e authored Mar 24, 2017 by Alan Stern Committed by Greg Kroah-Hartman Apr 08, 2017

USB: fix linked-list corruption in rh_call_control()



commit 1633682053a7ee8058e10c76722b9b28e97fb73f upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 0a1757cf

drivers/usb/core/hcd.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -499,8 +499,10 @@ 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;

		@@ -705,6 +707,7 @@ error:
		}

		kfree(tbuf);
		err_alloc:

		/* any errors get returned through the urb completion */
		spin_lock_irq(&hcd_root_hub_lock);