Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6

[pandora-kernel.git] / security / selinux / avc.c

diff --git a/security/selinux/avc.c b/security/selinux/avc.c
index 7f1a304..1d027e2 100644 (file)
--- a/security/selinux/avc.c
+++ b/security/selinux/avc.c
@@ -288,7 +288,6 @@ static struct avc_node *avc_alloc_node(void)
        if (!node)
                goto out;
 
-       INIT_RCU_HEAD(&node->rhead);
        INIT_HLIST_NODE(&node->list);
        avc_cache_stats_incr(allocations);
 
@@ -472,6 +471,7 @@ static void avc_audit_post_callback(struct audit_buffer *ab, void *a)
  * @avd: access vector decisions
  * @result: result from avc_has_perm_noaudit
  * @a:  auxiliary audit data
+ * @flags: VFS walk flags
  *
  * Audit the granting or denial of permissions in accordance
  * with the policy.  This function is typically called by
@@ -482,25 +482,59 @@ static void avc_audit_post_callback(struct audit_buffer *ab, void *a)
  * be performed under a lock, to allow the lock to be released
  * before calling the auditing code.
  */
-void avc_audit(u32 ssid, u32 tsid,
+int avc_audit(u32 ssid, u32 tsid,
               u16 tclass, u32 requested,
-              struct av_decision *avd, int result, struct common_audit_data *a)
+              struct av_decision *avd, int result, struct common_audit_data *a,
+              unsigned flags)
 {
        struct common_audit_data stack_data;
        u32 denied, audited;
        denied = requested & ~avd->allowed;
-       if (denied)
+       if (denied) {
                audited = denied & avd->auditdeny;
-       else if (result)
+               /*
+                * a->selinux_audit_data.auditdeny is TRICKY!  Setting a bit in
+                * this field means that ANY denials should NOT be audited if
+                * the policy contains an explicit dontaudit rule for that
+                * permission.  Take notice that this is unrelated to the
+                * actual permissions that were denied.  As an example lets
+                * assume:
+                *
+                * denied == READ
+                * avd.auditdeny & ACCESS == 0 (not set means explicit rule)
+                * selinux_audit_data.auditdeny & ACCESS == 1
+                *
+                * We will NOT audit the denial even though the denied
+                * permission was READ and the auditdeny checks were for
+                * ACCESS
+                */
+               if (a &&
+                   a->selinux_audit_data.auditdeny &&
+                   !(a->selinux_audit_data.auditdeny & avd->auditdeny))
+                       audited = 0;
+       } else if (result)
                audited = denied = requested;
        else
                audited = requested & avd->auditallow;
        if (!audited)
-               return;
+               return 0;
+
        if (!a) {
                a = &stack_data;
                COMMON_AUDIT_DATA_INIT(a, NONE);
        }
+
+       /*
+        * When in a RCU walk do the audit on the RCU retry.  This is because
+        * the collection of the dname in an inode audit message is not RCU
+        * safe.  Note this may drop some audits when the situation changes
+        * during retry. However this is logically just as if the operation
+        * happened a little later.
+        */
+       if ((a->type == LSM_AUDIT_DATA_FS) &&
+           (flags & IPERM_FLAG_RCU))
+               return -ECHILD;
+
        a->selinux_audit_data.tclass = tclass;
        a->selinux_audit_data.requested = requested;
        a->selinux_audit_data.ssid = ssid;
@@ -510,6 +544,7 @@ void avc_audit(u32 ssid, u32 tsid,
        a->lsm_pre_audit = avc_audit_pre_callback;
        a->lsm_post_audit = avc_audit_post_callback;
        common_lsm_audit(a);
+       return 0;
 }
 
 /**
@@ -774,6 +809,7 @@ int avc_has_perm_noaudit(u32 ssid, u32 tsid,
  * @tclass: target security class
  * @requested: requested permissions, interpreted based on @tclass
  * @auditdata: auxiliary audit data
+ * @flags: VFS walk flags
  *
  * Check the AVC to determine whether the @requested permissions are granted
  * for the SID pair (@ssid, @tsid), interpreting the permissions
@@ -783,14 +819,19 @@ int avc_has_perm_noaudit(u32 ssid, u32 tsid,
  * permissions are granted, -%EACCES if any permissions are denied, or
  * another -errno upon other errors.
  */
-int avc_has_perm(u32 ssid, u32 tsid, u16 tclass,
-                u32 requested, struct common_audit_data *auditdata)
+int avc_has_perm_flags(u32 ssid, u32 tsid, u16 tclass,
+                      u32 requested, struct common_audit_data *auditdata,
+                      unsigned flags)
 {
        struct av_decision avd;
-       int rc;
+       int rc, rc2;
 
        rc = avc_has_perm_noaudit(ssid, tsid, tclass, requested, 0, &avd);
-       avc_audit(ssid, tsid, tclass, requested, &avd, rc, auditdata);
+
+       rc2 = avc_audit(ssid, tsid, tclass, requested, &avd, rc, auditdata,
+                       flags);
+       if (rc2)
+               return rc2;
        return rc;
 }