usb: cdns3: fixed memory use after free at cdns3_gadget_ep_disable()

  ...
  cdns3_gadget_ep_free_request(&priv_ep->endpoint, &priv_req->request);
  list_del_init(&priv_req->list);
  ...

'priv_req' actually free at cdns3_gadget_ep_free_request(). But
list_del_init() use priv_req->list after it.

[ 1542.642868][  T534] BUG: KFENCE: use-after-free read in __list_del_entry_valid+0x10/0xd4
[ 1542.642868][  T534]
[ 1542.653162][  T534] Use-after-free read at 0x000000009ed0ba99 (in kfence-#3):
[ 1542.660311][  T534]  __list_del_entry_valid+0x10/0xd4
[ 1542.665375][  T534]  cdns3_gadget_ep_disable+0x1f8/0x388 [cdns3]
[ 1542.671571][  T534]  usb_ep_disable+0x44/0xe4
[ 1542.675948][  T534]  ffs_func_eps_disable+0x64/0xc8
[ 1542.680839][  T534]  ffs_func_set_alt+0x74/0x368
[ 1542.685478][  T534]  ffs_func_disable+0x18/0x28

Move list_del_init() before cdns3_gadget_ep_free_request() to resolve this
problem.

Cc: stable@vger.kernel.org
Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver")
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Roger Quadros <rogerq@kernel.org>
Acked-by: Peter Chen <peter.chen@kernel.org>
Link: https://lore.kernel.org/r/20240202154217.661867-1-Frank.Li@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c
index aeca902ab6cc427b0946cf13ea9b8c725eb3f287..d6723d31fc6e2ce348a7942f6a06508a03e38ac7 100644 (file)
--- a/drivers/usb/cdns3/cdns3-gadget.c
+++ b/drivers/usb/cdns3/cdns3-gadget.c
@@ -2540,11 +2540,11 @@ static int cdns3_gadget_ep_disable(struct usb_ep *ep)
 
        while (!list_empty(&priv_ep->wa2_descmiss_req_list)) {
                priv_req = cdns3_next_priv_request(&priv_ep->wa2_descmiss_req_list);
+               list_del_init(&priv_req->list);
 
                kfree(priv_req->request.buf);
                cdns3_gadget_ep_free_request(&priv_ep->endpoint,
                                             &priv_req->request);
-               list_del_init(&priv_req->list);
                --priv_ep->wa2_counter;
        }