From: Sriharsha Allenki sallenki@codeaurora.org
commit f63ec55ff904b2f2e126884fcad93175f16ab4bb upstream.
In AIO case, the request is freed up if ep_queue fails. However, io_data->req still has the reference to this freed request. In the case of this failure if there is aio_cancel call on this io_data it will lead to an invalid dequeue operation and a potential use after free issue. Fix this by setting the io_data->req to NULL when the request is freed as part of queue failure.
Fixes: 2e4c7553cd6f ("usb: gadget: f_fs: add aio support") Signed-off-by: Sriharsha Allenki sallenki@codeaurora.org CC: stable stable@vger.kernel.org Reviewed-by: Peter Chen peter.chen@nxp.com Link: https://lore.kernel.org/r/20200326115620.12571-1-sallenki@codeaurora.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/usb/gadget/function/f_fs.c | 1 + 1 file changed, 1 insertion(+)
--- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -1036,6 +1036,7 @@ static ssize_t ffs_epfile_io(struct file
ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC); if (unlikely(ret)) { + io_data->req = NULL; usb_ep_free_request(ep->ep, req); goto error_lock; }