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)) -- 2.27.0