[PATCH 5.10 090/122] usb: cdns3: fixed memory use after free at cdns3_gadget_ep_disable()

Greg Kroah-Hartman
2024-02-27T14:29:38Z

From: Frank Li <Frank.Li@nxp.com>

commit cd45f99034b0c8c9cb346dd0d6407a95ca3d36f6 upstream.

...
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>
---
drivers/usb/cdns3/gadget.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/usb/cdns3/gadget.c
+++ b/drivers/usb/cdns3/gadget.c
@@ -2538,11 +2538,11 @@ static int cdns3_gadget_ep_disable(struc

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;
}