From 0f8db8cc73df60b3de9a5eebd8f117b56eff5b03 Mon Sep 17 00:00:00 2001 From: Alexey Kodanev Date: Fri, 11 May 2018 20:15:11 +0300 Subject: [PATCH 1/3] selinux: add AF_UNSPEC and INADDR_ANY checks to selinux_socket_bind() 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 Signed-off-by: Paul Moore --- 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 21b377aef69a..16df6cca9a1b 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -4568,6 +4568,7 @@ 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; @@ -4579,11 +4580,11 @@ 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; @@ -4593,11 +4594,20 @@ 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; @@ -4609,13 +4619,7 @@ 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) { @@ -4673,7 +4677,7 @@ 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; @@ -4686,6 +4690,11 @@ 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) From 88b7d370bb4b1280717ebdacd6748456f9ba484f Mon Sep 17 00:00:00 2001 From: Alexey Kodanev Date: Fri, 11 May 2018 20:15:12 +0300 Subject: [PATCH 2/3] selinux: fix address family in bind() and connect() to match address/port Since sctp_bindx() and sctp_connectx() can have multiple addresses, sk_family can differ from sa_family. Therefore, selinux_socket_bind() and selinux_socket_connect_helper(), which process sockaddr structure (address and port), should use the address family from that structure too, and not from the socket one. The initialization of the data for the audit record is moved above, in selinux_socket_bind(), so that there is no duplicate changes and code. Fixes: d452930fd3b9 ("selinux: Add SCTP support") Suggested-by: Paul Moore Signed-off-by: Alexey Kodanev Signed-off-by: Paul Moore --- security/selinux/hooks.c | 18 +++++++----------- 1 file changed, 7 insertions(+), 11 deletions(-) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 16df6cca9a1b..f5f2d6a582f0 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -4622,6 +4622,11 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in goto err_af; } + ad.type = LSM_AUDIT_DATA_NET; + ad.u.net = &net; + ad.u.net->sport = htons(snum); + ad.u.net->family = family_sa; + if (snum) { int low, high; @@ -4633,10 +4638,6 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in snum, &sid); if (err) goto out; - ad.type = LSM_AUDIT_DATA_NET; - ad.u.net = &net; - ad.u.net->sport = htons(snum); - ad.u.net->family = family; err = avc_has_perm(&selinux_state, sksec->sid, sid, sksec->sclass, @@ -4668,15 +4669,10 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in break; } - err = sel_netnode_sid(addrp, family, &sid); + err = sel_netnode_sid(addrp, family_sa, &sid); if (err) goto out; - ad.type = LSM_AUDIT_DATA_NET; - ad.u.net = &net; - ad.u.net->sport = htons(snum); - ad.u.net->family = family; - if (family_sa == AF_INET) ad.u.net->v4info.saddr = addr4->sin_addr.s_addr; else @@ -4772,7 +4768,7 @@ static int selinux_socket_connect_helper(struct socket *sock, ad.type = LSM_AUDIT_DATA_NET; ad.u.net = &net; ad.u.net->dport = htons(snum); - ad.u.net->family = sk->sk_family; + ad.u.net->family = address->sa_family; err = avc_has_perm(&selinux_state, sksec->sid, sid, sksec->sclass, perm, &ad); if (err) From 4152dc91b5932e7fe49a5afed62a068b2f31d196 Mon Sep 17 00:00:00 2001 From: Alexey Kodanev Date: Fri, 11 May 2018 20:15:13 +0300 Subject: [PATCH 3/3] selinux: correctly handle sa_family cases in selinux_sctp_bind_connect() Allow to pass the socket address structure with AF_UNSPEC family for compatibility purposes. selinux_socket_bind() will further check it for INADDR_ANY and selinux_socket_connect_helper() should return EINVAL. For a bad address family return EINVAL instead of AFNOSUPPORT error, i.e. what is expected from SCTP protocol in such case. Fixes: d452930fd3b9 ("selinux: Add SCTP support") Suggested-by: Paul Moore Signed-off-by: Alexey Kodanev Signed-off-by: Paul Moore --- security/selinux/hooks.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index f5f2d6a582f0..efeb1db8f61d 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -5269,6 +5269,7 @@ static int selinux_sctp_bind_connect(struct sock *sk, int optname, while (walk_size < addrlen) { addr = addr_buf; switch (addr->sa_family) { + case AF_UNSPEC: case AF_INET: len = sizeof(struct sockaddr_in); break; @@ -5276,7 +5277,7 @@ static int selinux_sctp_bind_connect(struct sock *sk, int optname, len = sizeof(struct sockaddr_in6); break; default: - return -EAFNOSUPPORT; + return -EINVAL; } err = -EINVAL;