From 30b9c54a707db4155735cf71f4600241c1b7b6ff Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Mon, 14 Jun 2021 19:13:38 -0700 Subject: [PATCH] skmsg: Clear skb redirect pointer before dropping it When we drop skb inside sk_psock_skb_redirect(), we have to clear its skb->_sk_redir pointer too, otherwise kfree_skb() would misinterpret it as a valid skb->_skb_refdst and dst_release() would eventually complain. Fixes: e3526bb92a20 ("skmsg: Move sk_redir from TCP_SKB_CB to skb") Reported-by: Jiang Wang Signed-off-by: Cong Wang Signed-off-by: Daniel Borkmann Acked-by: John Fastabend Acked-by: Jakub Sitnicki Link: https://lore.kernel.org/bpf/20210615021342.7416-5-xiyou.wangcong@gmail.com --- net/core/skmsg.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/core/skmsg.c b/net/core/skmsg.c index f9a81b3..4334720 100644 --- a/net/core/skmsg.c +++ b/net/core/skmsg.c @@ -843,12 +843,14 @@ static void sk_psock_skb_redirect(struct sk_buff *skb) * a socket that is in this state so we drop the skb. */ if (!psock_other || sock_flag(sk_other, SOCK_DEAD)) { + skb_bpf_redirect_clear(skb); kfree_skb(skb); return; } spin_lock_bh(&psock_other->ingress_lock); if (!sk_psock_test_state(psock_other, SK_PSOCK_TX_ENABLED)) { spin_unlock_bh(&psock_other->ingress_lock); + skb_bpf_redirect_clear(skb); kfree_skb(skb); return; } -- 2.7.4