summaryrefslogtreecommitdiff
path: root/net
diff options
context:
space:
mode:
authorEric Dumazet <edumazet@google.com>2024-06-06 15:46:51 +0000
committerDavid S. Miller <davem@davemloft.net>2024-06-10 13:11:22 +0100
commitd37fe4255abe8e7b419b90c5847e8ec2b8debb08 (patch)
treeb673e099e58133c68a248c87d757e8a43958dd5b /net
parent5add2f7288468f35a374620dabf126c13baaea9c (diff)
tcp: fix race in tcp_v6_syn_recv_sock()
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>
Diffstat (limited to 'net')
-rw-r--r--net/ipv6/tcp_ipv6.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 8c577b651bfc..729faf8bd366 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1439,7 +1439,6 @@ 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);
inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk);
@@ -1450,6 +1449,8 @@ 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;