[v2,8/9] selinux: Add IB Port SMP access vector
diff mbox

Message ID 1468537011-20407-9-git-send-email-danielj@mellanox.com
State New
Headers show

Commit Message

Daniel Jurgens July 14, 2016, 10:56 p.m. UTC
From: Daniel Jurgens <danielj@mellanox.com>

Add a type for Infiniband ports and an access vector for subnet
management packets. Implement the ib_port_smp hook to check that the
caller has permission to send and receive SMPs on the end port specified
by the device name and port. Add interface to query the SID for a IB
port, which walks the IB_PORT ocontexts to find an entry for the
given name and port.

Signed-off-by: Daniel Jurgens <danielj@mellanox.com>

---
v2:
- Shorted ib_end_port. Paul Moore
- Pass void blobs to security hooks. Paul Moore
- Log specific IB port info in audit log. Paul Moore
- Don't create a new intial sid, use unlabeled. Stephen Smalley
- Changed "smp" to "manage_subnet". Paul Moore
---
 include/linux/lsm_audit.h           |   32 ++++++++++++++++----------
 security/lsm_audit.c                |    5 ++++
 security/selinux/hooks.c            |   23 +++++++++++++++++++
 security/selinux/include/classmap.h |    2 +
 security/selinux/include/security.h |    2 +
 security/selinux/ss/services.c      |   42 +++++++++++++++++++++++++++++++++++
 6 files changed, 94 insertions(+), 12 deletions(-)

Comments

Paul Moore July 22, 2016, 7:26 p.m. UTC | #1
On Thu, Jul 14, 2016 at 6:56 PM, Dan Jurgens <danielj@mellanox.com> wrote:
> From: Daniel Jurgens <danielj@mellanox.com>
>
> Add a type for Infiniband ports and an access vector for subnet
> management packets. Implement the ib_port_smp hook to check that the
> caller has permission to send and receive SMPs on the end port specified
> by the device name and port. Add interface to query the SID for a IB
> port, which walks the IB_PORT ocontexts to find an entry for the
> given name and port.
>
> Signed-off-by: Daniel Jurgens <danielj@mellanox.com>

...

> diff --git a/security/lsm_audit.c b/security/lsm_audit.c
> index 2546d82..95632a9 100644
> --- a/security/lsm_audit.c
> +++ b/security/lsm_audit.c
> @@ -410,6 +410,11 @@ static void dump_common_audit_data(struct audit_buffer *ab,
>                                  a->u.pkey->pkey, &sbn_pfx);
>                 break;
>         }
> +       case LSM_AUDIT_DATA_IB_PORT:
> +               audit_log_format(ab, " device=");
> +               audit_log_untrustedstring(ab, a->u.ib_port->dev_name);

The device name comes from the driver, right?  We only need to use the
"untrustedstring" logging variant when we are dealing with strings
from userspace that have no guarantees on what they might contain.
Check the audit_string_contains_control() function to see what we
consider "bad" characters.

> +               audit_log_format(ab, " port=%u", a->u.ib_port->port);

Based on our other conversations, I'm guessing that should be " endport=%u"?

> +               break;
>         } /* switch (a->type) */
>  }
>
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index d9c4bfa..40ad0e8 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -6017,6 +6017,28 @@ static int selinux_ib_pkey_access(u64 subnet_prefix, u16 pkey_val, void *ib_sec)
>                             INFINIBAND_PKEY__ACCESS, &ad);
>  }
>
> +static int selinux_ib_port_manage_subnet(const char *dev_name, u8 port, void *ib_sec)
> +{

See my previous comments about argument ordering, in other words, put
ib_sec first to help preserve my sanity in the future.

> +       struct common_audit_data ad;
> +       int err;
> +       u32 sid = 0;
> +       struct ib_security_struct *sec = ib_sec;
> +       struct lsm_ib_port_audit ib_port;
> +
> +       err = security_ib_port_sid(dev_name, port, &sid);
> +
> +       if (err)
> +               return err;
> +
> +       ad.type = LSM_AUDIT_DATA_IB_PORT;
> +       strncpy(ib_port.dev_name, dev_name, sizeof(ib_port.dev_name));
> +       ib_port.port = port;
> +       ad.u.ib_port = &ib_port;
> +       return avc_has_perm(sec->sid, sid,
> +                           SECCLASS_INFINIBAND_PORT,
> +                           INFINIBAND_PORT__MANAGE_SUBNET, &ad);
> +}
> +
Daniel Jurgens July 27, 2016, 4:27 p.m. UTC | #2
On 7/22/2016 2:26 PM, Paul Moore wrote:
> On Thu, Jul 14, 2016 at 6:56 PM, Dan Jurgens <danielj@mellanox.com> wrote:
>
>> +               audit_log_format(ab, " port=%u", a->u.ib_port->port);
> Based on our other conversations, I'm guessing that should be " endport=%u"?

I think port is fine there, device name and port number.  Together they are an "endport".
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Patch
diff mbox

diff --git a/include/linux/lsm_audit.h b/include/linux/lsm_audit.h
index 8ff7eae..d2f6bda 100644
--- a/include/linux/lsm_audit.h
+++ b/include/linux/lsm_audit.h
@@ -21,6 +21,7 @@ 
 #include <linux/path.h>
 #include <linux/key.h>
 #include <linux/skbuff.h>
+#include <rdma/ib_verbs.h>
 
 struct lsm_network_audit {
 	int netif;
@@ -50,21 +51,27 @@  struct lsm_pkey_audit {
 	u16	pkey;
 };
 
+struct lsm_ib_port_audit {
+	char	dev_name[IB_DEVICE_NAME_MAX];
+	u8	port;
+};
+
 /* Auxiliary data to use in generating the audit record. */
 struct common_audit_data {
 	char type;
-#define LSM_AUDIT_DATA_PATH	1
-#define LSM_AUDIT_DATA_NET	2
-#define LSM_AUDIT_DATA_CAP	3
-#define LSM_AUDIT_DATA_IPC	4
-#define LSM_AUDIT_DATA_TASK	5
-#define LSM_AUDIT_DATA_KEY	6
-#define LSM_AUDIT_DATA_NONE	7
-#define LSM_AUDIT_DATA_KMOD	8
-#define LSM_AUDIT_DATA_INODE	9
-#define LSM_AUDIT_DATA_DENTRY	10
-#define LSM_AUDIT_DATA_IOCTL_OP	11
-#define LSM_AUDIT_DATA_PKEY	12
+#define LSM_AUDIT_DATA_PATH		1
+#define LSM_AUDIT_DATA_NET		2
+#define LSM_AUDIT_DATA_CAP		3
+#define LSM_AUDIT_DATA_IPC		4
+#define LSM_AUDIT_DATA_TASK		5
+#define LSM_AUDIT_DATA_KEY		6
+#define LSM_AUDIT_DATA_NONE		7
+#define LSM_AUDIT_DATA_KMOD		8
+#define LSM_AUDIT_DATA_INODE		9
+#define LSM_AUDIT_DATA_DENTRY		10
+#define LSM_AUDIT_DATA_IOCTL_OP		11
+#define LSM_AUDIT_DATA_PKEY		12
+#define LSM_AUDIT_DATA_IB_PORT		13
 	union 	{
 		struct path path;
 		struct dentry *dentry;
@@ -82,6 +89,7 @@  struct common_audit_data {
 		char *kmod_name;
 		struct lsm_ioctlop_audit *op;
 		struct lsm_pkey_audit *pkey;
+		struct lsm_ib_port_audit *ib_port;
 	} u;
 	/* this union contains LSM specific data */
 	union {
diff --git a/security/lsm_audit.c b/security/lsm_audit.c
index 2546d82..95632a9 100644
--- a/security/lsm_audit.c
+++ b/security/lsm_audit.c
@@ -410,6 +410,11 @@  static void dump_common_audit_data(struct audit_buffer *ab,
 				 a->u.pkey->pkey, &sbn_pfx);
 		break;
 	}
+	case LSM_AUDIT_DATA_IB_PORT:
+		audit_log_format(ab, " device=");
+		audit_log_untrustedstring(ab, a->u.ib_port->dev_name);
+		audit_log_format(ab, " port=%u", a->u.ib_port->port);
+		break;
 	} /* switch (a->type) */
 }
 
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index d9c4bfa..40ad0e8 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -6017,6 +6017,28 @@  static int selinux_ib_pkey_access(u64 subnet_prefix, u16 pkey_val, void *ib_sec)
 			    INFINIBAND_PKEY__ACCESS, &ad);
 }
 
+static int selinux_ib_port_manage_subnet(const char *dev_name, u8 port, void *ib_sec)
+{
+	struct common_audit_data ad;
+	int err;
+	u32 sid = 0;
+	struct ib_security_struct *sec = ib_sec;
+	struct lsm_ib_port_audit ib_port;
+
+	err = security_ib_port_sid(dev_name, port, &sid);
+
+	if (err)
+		return err;
+
+	ad.type = LSM_AUDIT_DATA_IB_PORT;
+	strncpy(ib_port.dev_name, dev_name, sizeof(ib_port.dev_name));
+	ib_port.port = port;
+	ad.u.ib_port = &ib_port;
+	return avc_has_perm(sec->sid, sid,
+			    SECCLASS_INFINIBAND_PORT,
+			    INFINIBAND_PORT__MANAGE_SUBNET, &ad);
+}
+
 static int selinux_ib_alloc_security(void **ib_sec)
 {
 	struct ib_security_struct *sec;
@@ -6219,6 +6241,7 @@  static struct security_hook_list selinux_hooks[] = {
 	LSM_HOOK_INIT(tun_dev_open, selinux_tun_dev_open),
 #ifdef CONFIG_SECURITY_INFINIBAND
 	LSM_HOOK_INIT(ib_pkey_access, selinux_ib_pkey_access),
+	LSM_HOOK_INIT(ib_port_manage_subnet, selinux_ib_port_manage_subnet),
 	LSM_HOOK_INIT(ib_alloc_security, selinux_ib_alloc_security),
 	LSM_HOOK_INIT(ib_free_security, selinux_ib_free_security),
 #endif
diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h
index d42dd4d..9ba1238 100644
--- a/security/selinux/include/classmap.h
+++ b/security/selinux/include/classmap.h
@@ -167,5 +167,7 @@  struct security_class_mapping secclass_map[] = {
 	  { COMMON_CAP2_PERMS, NULL } },
 	{ "infiniband_pkey",
 	  { "access", NULL } },
+	{ "infiniband_port",
+	  { "manage_subnet", NULL } },
 	{ NULL }
   };
diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h
index 8f1a66e..1d58583 100644
--- a/security/selinux/include/security.h
+++ b/security/selinux/include/security.h
@@ -182,6 +182,8 @@  int security_port_sid(u8 protocol, u16 port, u32 *out_sid);
 
 int security_pkey_sid(u64 subnet_prefix, u16 pkey_num, u32 *out_sid);
 
+int security_ib_port_sid(const char *dev_name, u8 port, u32 *out_sid);
+
 int security_netif_sid(char *name, u32 *if_sid);
 
 int security_node_sid(u16 domain, void *addr, u32 addrlen,
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index ba346da..4c97952 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -2270,6 +2270,48 @@  out:
 }
 
 /**
+ * security_ib_port_sid - Obtain the SID for a subnet management interface.
+ * @dev_name: device name
+ * @port: port number
+ * @out_sid: security identifier
+ */
+int security_ib_port_sid(const char *dev_name, u8 port, u32 *out_sid)
+{
+	struct ocontext *c;
+	int rc = 0;
+
+	read_lock(&policy_rwlock);
+
+	c = policydb.ocontexts[OCON_IB_PORT];
+	while (c) {
+		if (c->u.ib_port.port == port &&
+		    !strncmp(c->u.ib_port.dev_name,
+			    dev_name,
+			    IB_DEVICE_NAME_MAX))
+			break;
+
+		c = c->next;
+	}
+
+	if (c) {
+		if (!c->sid[0]) {
+			rc = sidtab_context_to_sid(&sidtab,
+						   &c->context[0],
+						   &c->sid[0]);
+			if (rc)
+				goto out;
+		}
+		*out_sid = c->sid[0];
+	} else {
+		*out_sid = SECINITSID_UNLABELED;
+	}
+
+out:
+	read_unlock(&policy_rwlock);
+	return rc;
+}
+
+/**
  * security_netif_sid - Obtain the SID for a network interface.
  * @name: interface name
  * @if_sid: interface SID