[PATCH v1 net 2/2] dccp/tcp: Call security_inet_conn_request() after setting IPv6 addresses.

Kuniyuki Iwashima
2023-10-30T20:12:08Z

Initially, commit 4237c75c0a35 ("[MLSXFRM]: Auto-labeling of child
sockets") introduced security_inet_conn_request() in some functions
where reqsk is allocated. The hook is added just after the allocation,
so reqsk's IPv6 remote address was not initialised then.

However, SELinux/Smack started to read it in netlbl_req_setattr()
after commit e1adea927080 ("calipso: Allow request sockets to be
relabelled by the lsm.").

Commit 284904aa7946 ("lsm: Relocate the IPv4 security_inet_conn_request()
hooks") fixed that kind of issue only in TCPv4 because IPv6 labeling was
not supported at that time. Finally, the same issue was introduced again
in IPv6.

Let's apply the same fix on DCCPv6 and TCPv6.

Fixes: e1adea927080 ("calipso: Allow request sockets to be relabelled by the lsm.")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
---
Cc: Huw Davies <huw@codeweavers.com>
Cc: Paul Moore <paul@paul-moore.com>
---
net/dccp/ipv6.c | 6 +++---
net/ipv6/syncookies.c | 7 ++++---
2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index 8d344b219f84..4550b680665a 100644
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -360,15 +360,15 @@ static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
if (dccp_parse_options(sk, dreq, skb))
goto drop_and_free;

- if (security_inet_conn_request(sk, skb, req))
- goto drop_and_free;
-
ireq = inet_rsk(req);
ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
ireq->ireq_family = AF_INET6;
ireq->ir_mark = inet_request_mark(sk, skb);

+ if (security_inet_conn_request(sk, skb, req))
+ goto drop_and_free;
+
if (ipv6_opt_accepted(sk, skb, IP6CB(skb)) ||
np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c
index 500f6ed3b8cf..12eedc6ca2cc 100644
--- a/net/ipv6/syncookies.c
+++ b/net/ipv6/syncookies.c
@@ -181,14 +181,15 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
treq = tcp_rsk(req);
treq->tfo_listener = false;

- if (security_inet_conn_request(sk, skb, req))
- goto out_free;
-
req->mss = mss;
ireq->ir_rmt_port = th->source;
ireq->ir_num = ntohs(th->dest);
ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
+
+ if (security_inet_conn_request(sk, skb, req))
+ goto out_free;
+
if (ipv6_opt_accepted(sk, skb, &TCP_SKB_CB(skb)->header.h6) ||
np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
--
2.30.2