security: pass asoc to sctp_assoc_request and sctp_sk_clone

This patch is to move secid and peer_secid from endpoint to association,
and pass asoc to sctp_assoc_request and sctp_sk_clone instead of ep. As
ep is the local endpoint and asoc represents a connection, and in SCTP
one sk/ep could have multiple asoc/connection, saving secid/peer_secid
for new asoc will overwrite the old asoc's.

Note that since asoc can be passed as NULL, security_sctp_assoc_request()
is moved to the place right after the new_asoc is created in
sctp_sf_do_5_1B_init() and sctp_sf_do_unexpected_init().

v1->v2:
  - fix the description of selinux_netlbl_skbuff_setsid(), as Jakub noticed.
  - fix the annotation in selinux_sctp_assoc_request(), as Richard Noticed.

Fixes: 72e89f5008 ("security: Add support for SCTP security hooks")
Reported-by: Prashanth Prahlad <pprahlad@redhat.com>
Reviewed-by: Richard Haines <richard_c_haines@btinternet.com>
Tested-by: Richard Haines <richard_c_haines@btinternet.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Xin Long 2021-11-02 08:02:47 -04:00 committed by David S. Miller
parent 843c3cbbdf
commit c081d53f97
11 changed files with 76 additions and 77 deletions

View File

@ -26,11 +26,11 @@ described in the `SCTP SELinux Support`_ chapter.
security_sctp_assoc_request()
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Passes the ``@ep`` and ``@chunk->skb`` of the association INIT packet to the
Passes the ``@asoc`` and ``@chunk->skb`` of the association INIT packet to the
security module. Returns 0 on success, error on failure.
::
@ep - pointer to sctp endpoint structure.
@asoc - pointer to sctp association structure.
@skb - pointer to skbuff of association packet.
@ -117,9 +117,9 @@ Called whenever a new socket is created by **accept**\(2)
calls **sctp_peeloff**\(3).
::
@ep - pointer to current sctp endpoint structure.
@asoc - pointer to current sctp association structure.
@sk - pointer to current sock structure.
@sk - pointer to new sock structure.
@newsk - pointer to new sock structure.
security_inet_conn_established()
@ -200,22 +200,22 @@ hooks with the SELinux specifics expanded below::
security_sctp_assoc_request()
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Passes the ``@ep`` and ``@chunk->skb`` of the association INIT packet to the
Passes the ``@asoc`` and ``@chunk->skb`` of the association INIT packet to the
security module. Returns 0 on success, error on failure.
::
@ep - pointer to sctp endpoint structure.
@asoc - pointer to sctp association structure.
@skb - pointer to skbuff of association packet.
The security module performs the following operations:
IF this is the first association on ``@ep->base.sk``, then set the peer
IF this is the first association on ``@asoc->base.sk``, then set the peer
sid to that in ``@skb``. This will ensure there is only one peer sid
assigned to ``@ep->base.sk`` that may support multiple associations.
assigned to ``@asoc->base.sk`` that may support multiple associations.
ELSE validate the ``@ep->base.sk peer_sid`` against the ``@skb peer sid``
ELSE validate the ``@asoc->base.sk peer_sid`` against the ``@skb peer sid``
to determine whether the association should be allowed or denied.
Set the sctp ``@ep sid`` to socket's sid (from ``ep->base.sk``) with
Set the sctp ``@asoc sid`` to socket's sid (from ``asoc->base.sk``) with
MLS portion taken from ``@skb peer sid``. This will be used by SCTP
TCP style sockets and peeled off connections as they cause a new socket
to be generated.
@ -259,13 +259,13 @@ security_sctp_sk_clone()
Called whenever a new socket is created by **accept**\(2) (i.e. a TCP style
socket) or when a socket is 'peeled off' e.g userspace calls
**sctp_peeloff**\(3). ``security_sctp_sk_clone()`` will set the new
sockets sid and peer sid to that contained in the ``@ep sid`` and
``@ep peer sid`` respectively.
sockets sid and peer sid to that contained in the ``@asoc sid`` and
``@asoc peer sid`` respectively.
::
@ep - pointer to current sctp endpoint structure.
@asoc - pointer to current sctp association structure.
@sk - pointer to current sock structure.
@sk - pointer to new sock structure.
@newsk - pointer to new sock structure.
security_inet_conn_established()

View File

@ -329,11 +329,11 @@ LSM_HOOK(int, 0, tun_dev_create, void)
LSM_HOOK(int, 0, tun_dev_attach_queue, void *security)
LSM_HOOK(int, 0, tun_dev_attach, struct sock *sk, void *security)
LSM_HOOK(int, 0, tun_dev_open, void *security)
LSM_HOOK(int, 0, sctp_assoc_request, struct sctp_endpoint *ep,
LSM_HOOK(int, 0, sctp_assoc_request, struct sctp_association *asoc,
struct sk_buff *skb)
LSM_HOOK(int, 0, sctp_bind_connect, struct sock *sk, int optname,
struct sockaddr *address, int addrlen)
LSM_HOOK(void, LSM_RET_VOID, sctp_sk_clone, struct sctp_endpoint *ep,
LSM_HOOK(void, LSM_RET_VOID, sctp_sk_clone, struct sctp_association *asoc,
struct sock *sk, struct sock *newsk)
#endif /* CONFIG_SECURITY_NETWORK */

View File

@ -1027,9 +1027,9 @@
* Security hooks for SCTP
*
* @sctp_assoc_request:
* Passes the @ep and @chunk->skb of the association INIT packet to
* Passes the @asoc and @chunk->skb of the association INIT packet to
* the security module.
* @ep pointer to sctp endpoint structure.
* @asoc pointer to sctp association structure.
* @skb pointer to skbuff of association packet.
* Return 0 on success, error on failure.
* @sctp_bind_connect:
@ -1047,9 +1047,9 @@
* Called whenever a new socket is created by accept(2) (i.e. a TCP
* style socket) or when a socket is 'peeled off' e.g userspace
* calls sctp_peeloff(3).
* @ep pointer to current sctp endpoint structure.
* @asoc pointer to current sctp association structure.
* @sk pointer to current sock structure.
* @sk pointer to new sock structure.
* @newsk pointer to new sock structure.
*
* Security hooks for Infiniband
*

View File

@ -179,7 +179,7 @@ struct xfrm_policy;
struct xfrm_state;
struct xfrm_user_sec_ctx;
struct seq_file;
struct sctp_endpoint;
struct sctp_association;
#ifdef CONFIG_MMU
extern unsigned long mmap_min_addr;
@ -1425,10 +1425,10 @@ int security_tun_dev_create(void);
int security_tun_dev_attach_queue(void *security);
int security_tun_dev_attach(struct sock *sk, void *security);
int security_tun_dev_open(void *security);
int security_sctp_assoc_request(struct sctp_endpoint *ep, struct sk_buff *skb);
int security_sctp_assoc_request(struct sctp_association *asoc, struct sk_buff *skb);
int security_sctp_bind_connect(struct sock *sk, int optname,
struct sockaddr *address, int addrlen);
void security_sctp_sk_clone(struct sctp_endpoint *ep, struct sock *sk,
void security_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk,
struct sock *newsk);
#else /* CONFIG_SECURITY_NETWORK */
@ -1631,7 +1631,7 @@ static inline int security_tun_dev_open(void *security)
return 0;
}
static inline int security_sctp_assoc_request(struct sctp_endpoint *ep,
static inline int security_sctp_assoc_request(struct sctp_association *asoc,
struct sk_buff *skb)
{
return 0;
@ -1644,7 +1644,7 @@ static inline int security_sctp_bind_connect(struct sock *sk, int optname,
return 0;
}
static inline void security_sctp_sk_clone(struct sctp_endpoint *ep,
static inline void security_sctp_sk_clone(struct sctp_association *asoc,
struct sock *sk,
struct sock *newsk)
{

View File

@ -1355,16 +1355,6 @@ struct sctp_endpoint {
reconf_enable:1;
__u8 strreset_enable;
/* Security identifiers from incoming (INIT). These are set by
* security_sctp_assoc_request(). These will only be used by
* SCTP TCP type sockets and peeled off connections as they
* cause a new socket to be generated. security_sctp_sk_clone()
* will then plug these into the new socket.
*/
u32 secid;
u32 peer_secid;
};
/* Recover the outter endpoint structure. */
@ -2104,6 +2094,16 @@ struct sctp_association {
__u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
__u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
/* Security identifiers from incoming (INIT). These are set by
* security_sctp_assoc_request(). These will only be used by
* SCTP TCP type sockets and peeled off connections as they
* cause a new socket to be generated. security_sctp_sk_clone()
* will then plug these into the new socket.
*/
u32 secid;
u32 peer_secid;
struct rcu_head rcu;
};

View File

@ -326,11 +326,6 @@ enum sctp_disposition sctp_sf_do_5_1B_init(struct net *net,
struct sctp_packet *packet;
int len;
/* Update socket peer label if first association. */
if (security_sctp_assoc_request((struct sctp_endpoint *)ep,
chunk->skb))
return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
/* 6.10 Bundling
* An endpoint MUST NOT bundle INIT, INIT ACK or
* SHUTDOWN COMPLETE with any other chunks.
@ -415,6 +410,12 @@ enum sctp_disposition sctp_sf_do_5_1B_init(struct net *net,
if (!new_asoc)
goto nomem;
/* Update socket peer label if first association. */
if (security_sctp_assoc_request(new_asoc, chunk->skb)) {
sctp_association_free(new_asoc);
return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
}
if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
sctp_scope(sctp_source(chunk)),
GFP_ATOMIC) < 0)
@ -780,7 +781,6 @@ enum sctp_disposition sctp_sf_do_5_1D_ce(struct net *net,
}
}
/* Delay state machine commands until later.
*
* Re-build the bind address for the association is done in
@ -1517,11 +1517,6 @@ static enum sctp_disposition sctp_sf_do_unexpected_init(
struct sctp_packet *packet;
int len;
/* Update socket peer label if first association. */
if (security_sctp_assoc_request((struct sctp_endpoint *)ep,
chunk->skb))
return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
/* 6.10 Bundling
* An endpoint MUST NOT bundle INIT, INIT ACK or
* SHUTDOWN COMPLETE with any other chunks.
@ -1594,6 +1589,12 @@ static enum sctp_disposition sctp_sf_do_unexpected_init(
if (!new_asoc)
goto nomem;
/* Update socket peer label if first association. */
if (security_sctp_assoc_request(new_asoc, chunk->skb)) {
sctp_association_free(new_asoc);
return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
}
if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
sctp_scope(sctp_source(chunk)), GFP_ATOMIC) < 0)
goto nomem;
@ -2255,8 +2256,7 @@ enum sctp_disposition sctp_sf_do_5_2_4_dupcook(
}
/* Update socket peer label if first association. */
if (security_sctp_assoc_request((struct sctp_endpoint *)ep,
chunk->skb)) {
if (security_sctp_assoc_request(new_asoc, chunk->skb)) {
sctp_association_free(new_asoc);
return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
}

View File

@ -9412,7 +9412,6 @@ void sctp_copy_sock(struct sock *newsk, struct sock *sk,
struct inet_sock *inet = inet_sk(sk);
struct inet_sock *newinet;
struct sctp_sock *sp = sctp_sk(sk);
struct sctp_endpoint *ep = sp->ep;
newsk->sk_type = sk->sk_type;
newsk->sk_bound_dev_if = sk->sk_bound_dev_if;
@ -9457,9 +9456,9 @@ void sctp_copy_sock(struct sock *newsk, struct sock *sk,
net_enable_timestamp();
/* Set newsk security attributes from original sk and connection
* security attribute from ep.
* security attribute from asoc.
*/
security_sctp_sk_clone(ep, sk, newsk);
security_sctp_sk_clone(asoc, sk, newsk);
}
static inline void sctp_copy_descendant(struct sock *sk_to,

View File

@ -2367,9 +2367,9 @@ int security_tun_dev_open(void *security)
}
EXPORT_SYMBOL(security_tun_dev_open);
int security_sctp_assoc_request(struct sctp_endpoint *ep, struct sk_buff *skb)
int security_sctp_assoc_request(struct sctp_association *asoc, struct sk_buff *skb)
{
return call_int_hook(sctp_assoc_request, 0, ep, skb);
return call_int_hook(sctp_assoc_request, 0, asoc, skb);
}
EXPORT_SYMBOL(security_sctp_assoc_request);
@ -2381,10 +2381,10 @@ int security_sctp_bind_connect(struct sock *sk, int optname,
}
EXPORT_SYMBOL(security_sctp_bind_connect);
void security_sctp_sk_clone(struct sctp_endpoint *ep, struct sock *sk,
void security_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk,
struct sock *newsk)
{
call_void_hook(sctp_sk_clone, ep, sk, newsk);
call_void_hook(sctp_sk_clone, asoc, sk, newsk);
}
EXPORT_SYMBOL(security_sctp_sk_clone);

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@ -5339,10 +5339,10 @@ static void selinux_sock_graft(struct sock *sk, struct socket *parent)
* connect(2), sctp_connectx(3) or sctp_sendmsg(3) (with no association
* already present).
*/
static int selinux_sctp_assoc_request(struct sctp_endpoint *ep,
static int selinux_sctp_assoc_request(struct sctp_association *asoc,
struct sk_buff *skb)
{
struct sk_security_struct *sksec = ep->base.sk->sk_security;
struct sk_security_struct *sksec = asoc->base.sk->sk_security;
struct common_audit_data ad;
struct lsm_network_audit net = {0,};
u8 peerlbl_active;
@ -5359,7 +5359,7 @@ static int selinux_sctp_assoc_request(struct sctp_endpoint *ep,
/* This will return peer_sid = SECSID_NULL if there are
* no peer labels, see security_net_peersid_resolve().
*/
err = selinux_skb_peerlbl_sid(skb, ep->base.sk->sk_family,
err = selinux_skb_peerlbl_sid(skb, asoc->base.sk->sk_family,
&peer_sid);
if (err)
return err;
@ -5383,7 +5383,7 @@ static int selinux_sctp_assoc_request(struct sctp_endpoint *ep,
*/
ad.type = LSM_AUDIT_DATA_NET;
ad.u.net = &net;
ad.u.net->sk = ep->base.sk;
ad.u.net->sk = asoc->base.sk;
err = avc_has_perm(&selinux_state,
sksec->peer_sid, peer_sid, sksec->sclass,
SCTP_SOCKET__ASSOCIATION, &ad);
@ -5392,7 +5392,7 @@ static int selinux_sctp_assoc_request(struct sctp_endpoint *ep,
}
/* Compute the MLS component for the connection and store
* the information in ep. This will be used by SCTP TCP type
* the information in asoc. This will be used by SCTP TCP type
* sockets and peeled off connections as they cause a new
* socket to be generated. selinux_sctp_sk_clone() will then
* plug this into the new socket.
@ -5401,11 +5401,11 @@ static int selinux_sctp_assoc_request(struct sctp_endpoint *ep,
if (err)
return err;
ep->secid = conn_sid;
ep->peer_secid = peer_sid;
asoc->secid = conn_sid;
asoc->peer_secid = peer_sid;
/* Set any NetLabel labels including CIPSO/CALIPSO options. */
return selinux_netlbl_sctp_assoc_request(ep, skb);
return selinux_netlbl_sctp_assoc_request(asoc, skb);
}
/* Check if sctp IPv4/IPv6 addresses are valid for binding or connecting
@ -5490,7 +5490,7 @@ static int selinux_sctp_bind_connect(struct sock *sk, int optname,
}
/* Called whenever a new socket is created by accept(2) or sctp_peeloff(3). */
static void selinux_sctp_sk_clone(struct sctp_endpoint *ep, struct sock *sk,
static void selinux_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk,
struct sock *newsk)
{
struct sk_security_struct *sksec = sk->sk_security;
@ -5502,8 +5502,8 @@ static void selinux_sctp_sk_clone(struct sctp_endpoint *ep, struct sock *sk,
if (!selinux_policycap_extsockclass())
return selinux_sk_clone_security(sk, newsk);
newsksec->sid = ep->secid;
newsksec->peer_sid = ep->peer_secid;
newsksec->sid = asoc->secid;
newsksec->peer_sid = asoc->peer_secid;
newsksec->sclass = sksec->sclass;
selinux_netlbl_sctp_sk_clone(sk, newsk);
}

View File

@ -39,7 +39,7 @@ int selinux_netlbl_skbuff_getsid(struct sk_buff *skb,
int selinux_netlbl_skbuff_setsid(struct sk_buff *skb,
u16 family,
u32 sid);
int selinux_netlbl_sctp_assoc_request(struct sctp_endpoint *ep,
int selinux_netlbl_sctp_assoc_request(struct sctp_association *asoc,
struct sk_buff *skb);
int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family);
void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family);
@ -98,7 +98,7 @@ static inline int selinux_netlbl_skbuff_setsid(struct sk_buff *skb,
return 0;
}
static inline int selinux_netlbl_sctp_assoc_request(struct sctp_endpoint *ep,
static inline int selinux_netlbl_sctp_assoc_request(struct sctp_association *asoc,
struct sk_buff *skb)
{
return 0;

View File

@ -261,30 +261,30 @@ skbuff_setsid_return:
/**
* selinux_netlbl_sctp_assoc_request - Label an incoming sctp association.
* @ep: incoming association endpoint.
* @asoc: incoming association.
* @skb: the packet.
*
* Description:
* A new incoming connection is represented by @ep, ......
* A new incoming connection is represented by @asoc, ......
* Returns zero on success, negative values on failure.
*
*/
int selinux_netlbl_sctp_assoc_request(struct sctp_endpoint *ep,
int selinux_netlbl_sctp_assoc_request(struct sctp_association *asoc,
struct sk_buff *skb)
{
int rc;
struct netlbl_lsm_secattr secattr;
struct sk_security_struct *sksec = ep->base.sk->sk_security;
struct sk_security_struct *sksec = asoc->base.sk->sk_security;
struct sockaddr_in addr4;
struct sockaddr_in6 addr6;
if (ep->base.sk->sk_family != PF_INET &&
ep->base.sk->sk_family != PF_INET6)
if (asoc->base.sk->sk_family != PF_INET &&
asoc->base.sk->sk_family != PF_INET6)
return 0;
netlbl_secattr_init(&secattr);
rc = security_netlbl_sid_to_secattr(&selinux_state,
ep->secid, &secattr);
asoc->secid, &secattr);
if (rc != 0)
goto assoc_request_return;
@ -294,11 +294,11 @@ int selinux_netlbl_sctp_assoc_request(struct sctp_endpoint *ep,
if (ip_hdr(skb)->version == 4) {
addr4.sin_family = AF_INET;
addr4.sin_addr.s_addr = ip_hdr(skb)->saddr;
rc = netlbl_conn_setattr(ep->base.sk, (void *)&addr4, &secattr);
rc = netlbl_conn_setattr(asoc->base.sk, (void *)&addr4, &secattr);
} else if (IS_ENABLED(CONFIG_IPV6) && ip_hdr(skb)->version == 6) {
addr6.sin6_family = AF_INET6;
addr6.sin6_addr = ipv6_hdr(skb)->saddr;
rc = netlbl_conn_setattr(ep->base.sk, (void *)&addr6, &secattr);
rc = netlbl_conn_setattr(asoc->base.sk, (void *)&addr6, &secattr);
} else {
rc = -EAFNOSUPPORT;
}