From 6f96c142f77c96a34ac377a3616ee7abcd77fb4d Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Mon, 14 Jan 2013 07:12:13 +0000 Subject: selinux: add the "attach_queue" permission to the "tun_socket" class Add a new permission to align with the new TUN multiqueue support, "tun_socket:attach_queue". The corresponding SELinux reference policy patch is show below: diff --git a/policy/flask/access_vectors b/policy/flask/access_vectors index 28802c5..a0664a1 100644 --- a/policy/flask/access_vectors +++ b/policy/flask/access_vectors @@ -827,6 +827,9 @@ class kernel_service class tun_socket inherits socket +{ + attach_queue +} class x_pointer inherits x_device Signed-off-by: Paul Moore Acked-by: Eric Paris Tested-by: Jason Wang Signed-off-by: David S. Miller --- security/selinux/include/classmap.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'security') diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h index df2de54a958..14d04e63b1f 100644 --- a/security/selinux/include/classmap.h +++ b/security/selinux/include/classmap.h @@ -150,6 +150,6 @@ struct security_class_mapping secclass_map[] = { NULL } }, { "kernel_service", { "use_as_override", "create_files_as", NULL } }, { "tun_socket", - { COMMON_SOCK_PERMS, NULL } }, + { COMMON_SOCK_PERMS, "attach_queue", NULL } }, { NULL } }; -- cgit v1.2.3 From 5dbbaf2de89613d19a9286d4db0a535ca2735d26 Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Mon, 14 Jan 2013 07:12:19 +0000 Subject: tun: fix LSM/SELinux labeling of tun/tap devices This patch corrects some problems with LSM/SELinux that were introduced with the multiqueue patchset. The problem stems from the fact that the multiqueue work changed the relationship between the tun device and its associated socket; before the socket persisted for the life of the device, however after the multiqueue changes the socket only persisted for the life of the userspace connection (fd open). For non-persistent devices this is not an issue, but for persistent devices this can cause the tun device to lose its SELinux label. We correct this problem by adding an opaque LSM security blob to the tun device struct which allows us to have the LSM security state, e.g. SELinux labeling information, persist for the lifetime of the tun device. In the process we tweak the LSM hooks to work with this new approach to TUN device/socket labeling and introduce a new LSM hook, security_tun_dev_attach_queue(), to approve requests to attach to a TUN queue via TUNSETQUEUE. The SELinux code has been adjusted to match the new LSM hooks, the other LSMs do not make use of the LSM TUN controls. This patch makes use of the recently added "tun_socket:attach_queue" permission to restrict access to the TUNSETQUEUE operation. On older SELinux policies which do not define the "tun_socket:attach_queue" permission the access control decision for TUNSETQUEUE will be handled according to the SELinux policy's unknown permission setting. Signed-off-by: Paul Moore Acked-by: Eric Paris Tested-by: Jason Wang Signed-off-by: David S. Miller --- security/capability.c | 24 ++++++++++++++++--- security/security.c | 28 ++++++++++++++++++---- security/selinux/hooks.c | 50 ++++++++++++++++++++++++++++++--------- security/selinux/include/objsec.h | 4 ++++ 4 files changed, 87 insertions(+), 19 deletions(-) (limited to 'security') diff --git a/security/capability.c b/security/capability.c index 0fe5a026aef..57977508896 100644 --- a/security/capability.c +++ b/security/capability.c @@ -709,16 +709,31 @@ static void cap_req_classify_flow(const struct request_sock *req, { } +static int cap_tun_dev_alloc_security(void **security) +{ + return 0; +} + +static void cap_tun_dev_free_security(void *security) +{ +} + static int cap_tun_dev_create(void) { return 0; } -static void cap_tun_dev_post_create(struct sock *sk) +static int cap_tun_dev_attach_queue(void *security) +{ + return 0; +} + +static int cap_tun_dev_attach(struct sock *sk, void *security) { + return 0; } -static int cap_tun_dev_attach(struct sock *sk) +static int cap_tun_dev_open(void *security) { return 0; } @@ -1050,8 +1065,11 @@ void __init security_fixup_ops(struct security_operations *ops) set_to_cap_if_null(ops, secmark_refcount_inc); set_to_cap_if_null(ops, secmark_refcount_dec); set_to_cap_if_null(ops, req_classify_flow); + set_to_cap_if_null(ops, tun_dev_alloc_security); + set_to_cap_if_null(ops, tun_dev_free_security); set_to_cap_if_null(ops, tun_dev_create); - set_to_cap_if_null(ops, tun_dev_post_create); + set_to_cap_if_null(ops, tun_dev_open); + set_to_cap_if_null(ops, tun_dev_attach_queue); set_to_cap_if_null(ops, tun_dev_attach); #endif /* CONFIG_SECURITY_NETWORK */ #ifdef CONFIG_SECURITY_NETWORK_XFRM diff --git a/security/security.c b/security/security.c index daa97f4ac9d..7b88c6aeaed 100644 --- a/security/security.c +++ b/security/security.c @@ -1254,24 +1254,42 @@ void security_secmark_refcount_dec(void) } EXPORT_SYMBOL(security_secmark_refcount_dec); +int security_tun_dev_alloc_security(void **security) +{ + return security_ops->tun_dev_alloc_security(security); +} +EXPORT_SYMBOL(security_tun_dev_alloc_security); + +void security_tun_dev_free_security(void *security) +{ + security_ops->tun_dev_free_security(security); +} +EXPORT_SYMBOL(security_tun_dev_free_security); + int security_tun_dev_create(void) { return security_ops->tun_dev_create(); } EXPORT_SYMBOL(security_tun_dev_create); -void security_tun_dev_post_create(struct sock *sk) +int security_tun_dev_attach_queue(void *security) { - return security_ops->tun_dev_post_create(sk); + return security_ops->tun_dev_attach_queue(security); } -EXPORT_SYMBOL(security_tun_dev_post_create); +EXPORT_SYMBOL(security_tun_dev_attach_queue); -int security_tun_dev_attach(struct sock *sk) +int security_tun_dev_attach(struct sock *sk, void *security) { - return security_ops->tun_dev_attach(sk); + return security_ops->tun_dev_attach(sk, security); } EXPORT_SYMBOL(security_tun_dev_attach); +int security_tun_dev_open(void *security) +{ + return security_ops->tun_dev_open(security); +} +EXPORT_SYMBOL(security_tun_dev_open); + #endif /* CONFIG_SECURITY_NETWORK */ #ifdef CONFIG_SECURITY_NETWORK_XFRM diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 61a53367d02..ef26e9611ff 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -4399,6 +4399,24 @@ static void selinux_req_classify_flow(const struct request_sock *req, fl->flowi_secid = req->secid; } +static int selinux_tun_dev_alloc_security(void **security) +{ + struct tun_security_struct *tunsec; + + tunsec = kzalloc(sizeof(*tunsec), GFP_KERNEL); + if (!tunsec) + return -ENOMEM; + tunsec->sid = current_sid(); + + *security = tunsec; + return 0; +} + +static void selinux_tun_dev_free_security(void *security) +{ + kfree(security); +} + static int selinux_tun_dev_create(void) { u32 sid = current_sid(); @@ -4414,8 +4432,17 @@ static int selinux_tun_dev_create(void) NULL); } -static void selinux_tun_dev_post_create(struct sock *sk) +static int selinux_tun_dev_attach_queue(void *security) { + struct tun_security_struct *tunsec = security; + + return avc_has_perm(current_sid(), tunsec->sid, SECCLASS_TUN_SOCKET, + TUN_SOCKET__ATTACH_QUEUE, NULL); +} + +static int selinux_tun_dev_attach(struct sock *sk, void *security) +{ + struct tun_security_struct *tunsec = security; struct sk_security_struct *sksec = sk->sk_security; /* we don't currently perform any NetLabel based labeling here and it @@ -4425,20 +4452,19 @@ static void selinux_tun_dev_post_create(struct sock *sk) * cause confusion to the TUN user that had no idea network labeling * protocols were being used */ - /* see the comments in selinux_tun_dev_create() about why we don't use - * the sockcreate SID here */ - - sksec->sid = current_sid(); + sksec->sid = tunsec->sid; sksec->sclass = SECCLASS_TUN_SOCKET; + + return 0; } -static int selinux_tun_dev_attach(struct sock *sk) +static int selinux_tun_dev_open(void *security) { - struct sk_security_struct *sksec = sk->sk_security; + struct tun_security_struct *tunsec = security; u32 sid = current_sid(); int err; - err = avc_has_perm(sid, sksec->sid, SECCLASS_TUN_SOCKET, + err = avc_has_perm(sid, tunsec->sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__RELABELFROM, NULL); if (err) return err; @@ -4446,8 +4472,7 @@ static int selinux_tun_dev_attach(struct sock *sk) TUN_SOCKET__RELABELTO, NULL); if (err) return err; - - sksec->sid = sid; + tunsec->sid = sid; return 0; } @@ -5642,9 +5667,12 @@ static struct security_operations selinux_ops = { .secmark_refcount_inc = selinux_secmark_refcount_inc, .secmark_refcount_dec = selinux_secmark_refcount_dec, .req_classify_flow = selinux_req_classify_flow, + .tun_dev_alloc_security = selinux_tun_dev_alloc_security, + .tun_dev_free_security = selinux_tun_dev_free_security, .tun_dev_create = selinux_tun_dev_create, - .tun_dev_post_create = selinux_tun_dev_post_create, + .tun_dev_attach_queue = selinux_tun_dev_attach_queue, .tun_dev_attach = selinux_tun_dev_attach, + .tun_dev_open = selinux_tun_dev_open, #ifdef CONFIG_SECURITY_NETWORK_XFRM .xfrm_policy_alloc_security = selinux_xfrm_policy_alloc, diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h index 26c7eee1c30..aa47bcabb5f 100644 --- a/security/selinux/include/objsec.h +++ b/security/selinux/include/objsec.h @@ -110,6 +110,10 @@ struct sk_security_struct { u16 sclass; /* sock security class */ }; +struct tun_security_struct { + u32 sid; /* SID for the tun device sockets */ +}; + struct key_security_struct { u32 sid; /* SID of key */ }; -- cgit v1.2.3