SELinux: add boundary support and thread context assignment

[linux-2.6-omap-h63xx.git] / security / selinux / hooks.c

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 40d06c533f89fb574efd68507142fbe9b770d9f7..89f446d86054538d5299f8b1f547b10788789a4e 100644 (file)
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -957,7 +957,8 @@ out_err:
        return rc;
 }
 
-void selinux_write_opts(struct seq_file *m, struct security_mnt_opts *opts)
+static void selinux_write_opts(struct seq_file *m,
+                              struct security_mnt_opts *opts)
 {
        int i;
        char *prefix;
@@ -998,8 +999,12 @@ static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
        int rc;
 
        rc = selinux_get_mnt_opts(sb, &opts);
-       if (rc)
+       if (rc) {
+               /* before policy load we may get EINVAL, don't show anything */
+               if (rc == -EINVAL)
+                       rc = 0;
                return rc;
+       }
 
        selinux_write_opts(m, &opts);
 
@@ -1734,24 +1739,34 @@ static inline u32 file_to_av(struct file *file)
 
 /* Hook functions begin here. */
 
-static int selinux_ptrace(struct task_struct *parent,
-                         struct task_struct *child,
-                         unsigned int mode)
+static int selinux_ptrace_may_access(struct task_struct *child,
+                                    unsigned int mode)
 {
        int rc;
 
-       rc = secondary_ops->ptrace(parent, child, mode);
+       rc = secondary_ops->ptrace_may_access(child, mode);
        if (rc)
                return rc;
 
        if (mode == PTRACE_MODE_READ) {
-               struct task_security_struct *tsec = parent->security;
+               struct task_security_struct *tsec = current->security;
                struct task_security_struct *csec = child->security;
                return avc_has_perm(tsec->sid, csec->sid,
                                    SECCLASS_FILE, FILE__READ, NULL);
        }
 
-       return task_has_perm(parent, child, PROCESS__PTRACE);
+       return task_has_perm(current, child, PROCESS__PTRACE);
+}
+
+static int selinux_ptrace_traceme(struct task_struct *parent)
+{
+       int rc;
+
+       rc = secondary_ops->ptrace_traceme(parent);
+       if (rc)
+               return rc;
+
+       return task_has_perm(parent, current, PROCESS__PTRACE);
 }
 
 static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
@@ -3534,38 +3549,44 @@ out:
 #endif /* IPV6 */
 
 static int selinux_parse_skb(struct sk_buff *skb, struct avc_audit_data *ad,
-                            char **addrp, int src, u8 *proto)
+                            char **_addrp, int src, u8 *proto)
 {
-       int ret = 0;
+       char *addrp;
+       int ret;
 
        switch (ad->u.net.family) {
        case PF_INET:
                ret = selinux_parse_skb_ipv4(skb, ad, proto);
-               if (ret || !addrp)
-                       break;
-               *addrp = (char *)(src ? &ad->u.net.v4info.saddr :
-                                       &ad->u.net.v4info.daddr);
-               break;
+               if (ret)
+                       goto parse_error;
+               addrp = (char *)(src ? &ad->u.net.v4info.saddr :
+                                      &ad->u.net.v4info.daddr);
+               goto okay;
 
 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
        case PF_INET6:
                ret = selinux_parse_skb_ipv6(skb, ad, proto);
-               if (ret || !addrp)
-                       break;
-               *addrp = (char *)(src ? &ad->u.net.v6info.saddr :
-                                       &ad->u.net.v6info.daddr);
-               break;
+               if (ret)
+                       goto parse_error;
+               addrp = (char *)(src ? &ad->u.net.v6info.saddr :
+                                      &ad->u.net.v6info.daddr);
+               goto okay;
 #endif /* IPV6 */
        default:
-               break;
+               addrp = NULL;
+               goto okay;
        }
 
-       if (unlikely(ret))
-               printk(KERN_WARNING
-                      "SELinux: failure in selinux_parse_skb(),"
-                      " unable to parse packet\n");
-
+parse_error:
+       printk(KERN_WARNING
+              "SELinux: failure in selinux_parse_skb(),"
+              " unable to parse packet\n");
        return ret;
+
+okay:
+       if (_addrp)
+               *_addrp = addrp;
+       return 0;
 }
 
 /**
@@ -5205,8 +5226,12 @@ static int selinux_setprocattr(struct task_struct *p,
 
                if (sid == 0)
                        return -EINVAL;
-
-               /* Only allow single threaded processes to change context */
+               /*
+                * SELinux allows to change context in the following case only.
+                *  - Single threaded processes.
+                *  - Multi threaded processes intend to change its context into
+                *    more restricted domain (defined by TYPEBOUNDS statement).
+                */
                if (atomic_read(&p->mm->mm_users) != 1) {
                        struct task_struct *g, *t;
                        struct mm_struct *mm = p->mm;
@@ -5214,11 +5239,16 @@ static int selinux_setprocattr(struct task_struct *p,
                        do_each_thread(g, t) {
                                if (t->mm == mm && t != p) {
                                        read_unlock(&tasklist_lock);
-                                       return -EPERM;
+                                       error = security_bounded_transition(tsec->sid, sid);
+                                       if (!error)
+                                               goto boundary_ok;
+
+                                       return error;
                                }
                        } while_each_thread(g, t);
                        read_unlock(&tasklist_lock);
                }
+boundary_ok:
 
                /* Check permissions for the transition. */
                error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
@@ -5342,7 +5372,8 @@ static int selinux_key_getsecurity(struct key *key, char **_buffer)
 static struct security_operations selinux_ops = {
        .name =                         "selinux",
 
-       .ptrace =                       selinux_ptrace,
+       .ptrace_may_access =            selinux_ptrace_may_access,
+       .ptrace_traceme =               selinux_ptrace_traceme,
        .capget =                       selinux_capget,
        .capset_check =                 selinux_capset_check,
        .capset_set =                   selinux_capset_set,