On 7/24/20 9:45 AM, Cong Wang wrote:
> We have to detach sock from socket in qrtr_release(),
> otherwise skb->sk may still reference to this socket
> when the skb is released in tun->queue, particularly
> sk->sk_wq still points to &sock->wq, which leads to
> a UAF.
>
> Reported-and-tested-by: syzbot+6720d64f31c081c2f...@syzkaller.appspotmail.com
> Fixes: 28fb4e59a47d ("net: qrtr: Expose tunneling endpoint to user space")
> Cc: Bjorn Andersson <bjorn.anders...@linaro.org>
> Cc: Eric Dumazet <eric.duma...@gmail.com>
> Signed-off-by: Cong Wang <xiyou.wangc...@gmail.com>
> ---
> net/qrtr/qrtr.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/net/qrtr/qrtr.c b/net/qrtr/qrtr.c
> index 24a8c3c6da0d..300a104b9a0f 100644
> --- a/net/qrtr/qrtr.c
> +++ b/net/qrtr/qrtr.c
> @@ -1180,6 +1180,7 @@ static int qrtr_release(struct socket *sock)
> sk->sk_state_change(sk);
>
> sock_set_flag(sk, SOCK_DEAD);
> + sock_orphan(sk);
> sock->sk = NULL;
>
> if (!sock_flag(sk, SOCK_ZAPPED))
>
Reviewed-by: Eric Dumazet <eduma...@google.com>
