Re: [PATCH 1/2] usb: cdns3: fixed memory use after free at cdns3_gadget_ep_disable()

[Roger Quadros]

On 02/02/2024 07:18, Frank Li wrote:
>   ...
>   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@xxxxxxxxxxxxxxx>
> Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver")
> Signed-off-by: Frank Li <Frank.Li@xxxxxxx>

Reviewed-by: Roger Quadros <rogerq@xxxxxxxxxx>