From: Eric Dumazet <edumazet@google.com> stable inclusion from stable-v4.19.317 commit 06f208ae0670ef97b0bf253a5523863e113026b6 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAMPH5 CVE: Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... --------------------------- [ Upstream commit d37fe4255abe8e7b419b90c5847e8ec2b8debb08 ] tcp_v6_syn_recv_sock() calls ip6_dst_store() before inet_sk(newsk)->pinet6 has been set up. This means ip6_dst_store() writes over the parent (listener) np->dst_cookie. This is racy because multiple threads could share the same parent and their final np->dst_cookie could be wrong. Move ip6_dst_store() call after inet_sk(newsk)->pinet6 has been changed and after the copy of parent ipv6_pinfo. Fixes: e994b2f0fb92 ("tcp: do not lock listener to process SYN packets") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Yue Haibing <yuehaibing@huawei.com> --- net/ipv6/tcp_ipv6.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index e3878cf00dd4..4d9c9fbef8b9 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -1176,7 +1176,6 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff * */ newsk->sk_gso_type = SKB_GSO_TCPV6; - ip6_dst_store(newsk, dst, NULL, NULL); inet6_sk_rx_dst_set(newsk, skb); newtcp6sk = (struct tcp6_sock *)newsk; @@ -1188,6 +1187,8 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff * memcpy(newnp, np, sizeof(struct ipv6_pinfo)); + ip6_dst_store(newsk, dst, NULL, NULL); + newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr; newnp->saddr = ireq->ir_v6_loc_addr; newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr; -- 2.34.1