[PATCHv2 net 4/4] security: implement sctp_assoc_established hook in selinux
From: Xin Long <lucien.xin@gmail.com>
Date: 2021-11-02 12:03:05
Also in:
linux-sctp, linux-security-module, selinux
Subsystem:
selinux security module, the rest · Maintainers:
Paul Moore, Stephen Smalley, Linus Torvalds
Different from selinux_inet_conn_established(), it also gives the
secid to asoc->peer_secid in selinux_sctp_assoc_established(),
as one UDP-type socket may have more than one asocs.
Note that peer_secid in asoc will save the peer secid for this
asoc connection, and peer_sid in sksec will just keep the peer
secid for the latest connection. So the right use should be do
peeloff for UDP-type socket if there will be multiple asocs in
one socket, so that the peeloff socket has the right label for
its asoc.
v1->v2:
- call selinux_inet_conn_established() to reduce some code
duplication in selinux_sctp_assoc_established(), as Ondrej
suggested.
- when doing peeloff, it calls sock_create() where it actually
gets secid for socket from socket_sockcreate_sid(). So reuse
SECSID_WILD to ensure the peeloff socket keeps using that
secid after calling selinux_sctp_sk_clone() for client side.
Fixes: 72e89f50084c ("security: Add support for SCTP security hooks")
Reported-by: Prashanth Prahlad <redacted>
Reviewed-by: Richard Haines <redacted>
Tested-by: Richard Haines <redacted>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
---
security/selinux/hooks.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index a9977a2ae8ac..341cd5dccbf5 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c@@ -5519,7 +5519,8 @@ static void selinux_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk if (!selinux_policycap_extsockclass()) return selinux_sk_clone_security(sk, newsk); - newsksec->sid = asoc->secid; + if (asoc->secid != SECSID_WILD) + newsksec->sid = asoc->secid; newsksec->peer_sid = asoc->peer_secid; newsksec->sclass = sksec->sclass; selinux_netlbl_sctp_sk_clone(sk, newsk);
@@ -5575,6 +5576,16 @@ static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb) selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid); } +static void selinux_sctp_assoc_established(struct sctp_association *asoc, + struct sk_buff *skb) +{ + struct sk_security_struct *sksec = asoc->base.sk->sk_security; + + selinux_inet_conn_established(asoc->base.sk, skb); + asoc->peer_secid = sksec->peer_sid; + asoc->secid = SECSID_WILD; +} + static int selinux_secmark_relabel_packet(u32 sid) { const struct task_security_struct *__tsec;
@@ -7290,6 +7301,7 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(sctp_assoc_request, selinux_sctp_assoc_request), LSM_HOOK_INIT(sctp_sk_clone, selinux_sctp_sk_clone), LSM_HOOK_INIT(sctp_bind_connect, selinux_sctp_bind_connect), + LSM_HOOK_INIT(sctp_assoc_established, selinux_sctp_assoc_established), LSM_HOOK_INIT(inet_conn_request, selinux_inet_conn_request), LSM_HOOK_INIT(inet_csk_clone, selinux_inet_csk_clone), LSM_HOOK_INIT(inet_conn_established, selinux_inet_conn_established),
--
2.27.0