Commit d452930fd3b9 ("selinux: Add SCTP support") breaks compatibility
with the old programs that can pass sockaddr_in structure with AF_UNSPEC
and INADDR_ANY to bind(). As a result, bind() returns EAFNOSUPPORT error.
This was found with LTP/asapi_01 test.
Similar to commit 29c486df6a20 ("net: ipv4: relax AF_INET check in
bind()"), which relaxed AF_INET check for compatibility, add AF_UNSPEC
case to AF_INET and make sure that the address is INADDR_ANY.
Fixes: d452930fd3b9 ("selinux: Add SCTP support")
Signed-off-by: Alexey Kodanev <alexey.kodanev@xxxxxxxxxx>
---
v2: As suggested by Paul:
* return EINVAL for SCTP socket if sa_family is AF_UNSPEC and
address is not INADDR_ANY
* add new 'sa_family' variable so that it equals either AF_INET
or AF_INET6. Besides, it it will be used in the next patch that
fixes audit record.
security/selinux/hooks.c | 29 +++++++++++++++++++----------
1 file changed, 19 insertions(+), 10 deletions(-)
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 4cafe6a..1ed7004 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -4576,6 +4576,7 @@ static int selinux_socket_post_create(struct socket *sock, int family,
static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen)
{
struct sock *sk = sock->sk;
+ struct sk_security_struct *sksec = sk->sk_security;
u16 family;
int err;
@@ -4587,11 +4588,11 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in
family = sk->sk_family;
if (family == PF_INET || family == PF_INET6) {
char *addrp;
- struct sk_security_struct *sksec = sk->sk_security;
struct common_audit_data ad;
struct lsm_network_audit net = {0,};
struct sockaddr_in *addr4 = NULL;
struct sockaddr_in6 *addr6 = NULL;
+ u16 family_sa = address->sa_family;
unsigned short snum;
u32 sid, node_perm;
@@ -4601,11 +4602,20 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in
* need to check address->sa_family as it is possible to have
* sk->sk_family = PF_INET6 with addr->sa_family = AF_INET.
*/
- switch (address->sa_family) {
+ switch (family_sa) {
+ case AF_UNSPEC:
case AF_INET:
if (addrlen < sizeof(struct sockaddr_in))
return -EINVAL;
addr4 = (struct sockaddr_in *)address;
+ if (family_sa == AF_UNSPEC) {
+ /* see __inet_bind(), we only want to allow
+ * AF_UNSPEC if the address is INADDR_ANY
+ */
+ if (addr4->sin_addr.s_addr != htonl(INADDR_ANY))
+ goto err_af;
+ family_sa = AF_INET;
+ }
snum = ntohs(addr4->sin_port);
addrp = (char *)&addr4->sin_addr.s_addr;
break;
@@ -4617,13 +4627,7 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in
addrp = (char *)&addr6->sin6_addr.s6_addr;
break;
default:
- /* Note that SCTP services expect -EINVAL, whereas
- * others expect -EAFNOSUPPORT.
- */
- if (sksec->sclass == SECCLASS_SCTP_SOCKET)
- return -EINVAL;
- else
- return -EAFNOSUPPORT;
+ goto err_af;
}
if (snum) {
@@ -4681,7 +4685,7 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in
ad.u.net->sport = htons(snum);
ad.u.net->family = family;
- if (address->sa_family == AF_INET)
+ if (family_sa == AF_INET)
ad.u.net->v4info.saddr = addr4->sin_addr.s_addr;
else
ad.u.net->v6info.saddr = addr6->sin6_addr;
@@ -4694,6 +4698,11 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in
}
out:
return err;
+err_af:
+ /* Note that SCTP services expect -EINVAL, others -EAFNOSUPPORT. */
+ if (sksec->sclass == SECCLASS_SCTP_SOCKET)
+ return -EINVAL;
+ return -EAFNOSUPPORT;
}
/* This supports connect(2) and SCTP connect services such as sctp_connectx(3)
--
1.8.3.1
