From: Cong Wang cong.wang@bytedance.com
[ Upstream commit 30b9c54a707db4155735cf71f4600241c1b7b6ff ]
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 jiang.wang@bytedance.com Signed-off-by: Cong Wang cong.wang@bytedance.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Acked-by: John Fastabend john.fastabend@gmail.com Acked-by: Jakub Sitnicki jakub@cloudflare.com Link: https://lore.kernel.org/bpf/20210615021342.7416-5-xiyou.wangcong@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/core/skmsg.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/net/core/skmsg.c b/net/core/skmsg.c index 43ce17a6a585..df545748cd6a 100644 --- a/net/core/skmsg.c +++ b/net/core/skmsg.c @@ -866,12 +866,14 @@ 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; }