From: Cong Wang <xiyou.wangcong@xxxxxxxxx> [ Upstream commit af9f691f0f5bdd1ade65a7b84927639882d7c3e5 ] 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+6720d64f31c081c2f708@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: 28fb4e59a47d ("net: qrtr: Expose tunneling endpoint to user space") Cc: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx> Cc: Eric Dumazet <eric.dumazet@xxxxxxxxx> Signed-off-by: Cong Wang <xiyou.wangcong@xxxxxxxxx> Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/qrtr/qrtr.c | 1 + 1 file changed, 1 insertion(+) --- a/net/qrtr/qrtr.c +++ b/net/qrtr/qrtr.c @@ -1004,6 +1004,7 @@ static int qrtr_release(struct socket *s sk->sk_state_change(sk); sock_set_flag(sk, SOCK_DEAD); + sock_orphan(sk); sock->sk = NULL; if (!sock_flag(sk, SOCK_ZAPPED))