On Sat, Jan 01, 2022 at 01:21:38AM +0800, Hangyu Hua wrote:
> dev->config and dev->hs_config and dev->dev need to be cleaned if
> dev_config fails to avoid UAF.
>
> Signed-off-by: Hangyu Hua <hbh25y@xxxxxxxxx>
> ---
Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
> drivers/usb/gadget/legacy/inode.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c
> index eaad03c0252f..25c8809e0a38 100644
> --- a/drivers/usb/gadget/legacy/inode.c
> +++ b/drivers/usb/gadget/legacy/inode.c
> @@ -1875,8 +1875,8 @@ dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
>
> value = usb_gadget_probe_driver(&gadgetfs_driver);
> if (value != 0) {
> - kfree (dev->buf);
> - dev->buf = NULL;
> + spin_lock_irq(&dev->lock);
> + goto fail;
> } else {
> /* at this point "good" hardware has for the first time
> * let the USB the host see us. alternatively, if users
> @@ -1893,6 +1893,9 @@ dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
> return value;
>
> fail:
> + dev->config = NULL;
> + dev->hs_config = NULL;
> + dev->dev = NULL;
> spin_unlock_irq (&dev->lock);
> pr_debug ("%s: %s fail %zd, %p\n", shortname, __func__, value, dev);
> kfree (dev->buf);
> --
> 2.25.1
>
