[PATCH] VFS: Permit filesystem to perform statfs with a known root dentry

[linux-2.6] / security / selinux / hooks.c

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 54adc9d31e9248ae3b1ca00ed0cc166a533c814e..093efba4d9b6aa73ad7561f62aa8aac810a35cd6 100644 (file)
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -1903,13 +1903,13 @@ static int selinux_sb_kern_mount(struct super_block *sb, void *data)
        return superblock_has_perm(current, sb, FILESYSTEM__MOUNT, &ad);
 }
 
-static int selinux_sb_statfs(struct super_block *sb)
+static int selinux_sb_statfs(struct dentry *dentry)
 {
        struct avc_audit_data ad;
 
        AVC_AUDIT_DATA_INIT(&ad,FS);
-       ad.u.fs.dentry = sb->s_root;
-       return superblock_has_perm(current, sb, FILESYSTEM__GETATTR, &ad);
+       ad.u.fs.dentry = dentry->d_sb->s_root;
+       return superblock_has_perm(current, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
 }
 
 static int selinux_mount(char * dev_name,
@@ -4252,6 +4252,57 @@ static int selinux_setprocattr(struct task_struct *p,
        return size;
 }
 
+#ifdef CONFIG_KEYS
+
+static int selinux_key_alloc(struct key *k, struct task_struct *tsk)
+{
+       struct task_security_struct *tsec = tsk->security;
+       struct key_security_struct *ksec;
+
+       ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL);
+       if (!ksec)
+               return -ENOMEM;
+
+       ksec->obj = k;
+       ksec->sid = tsec->sid;
+       k->security = ksec;
+
+       return 0;
+}
+
+static void selinux_key_free(struct key *k)
+{
+       struct key_security_struct *ksec = k->security;
+
+       k->security = NULL;
+       kfree(ksec);
+}
+
+static int selinux_key_permission(key_ref_t key_ref,
+                           struct task_struct *ctx,
+                           key_perm_t perm)
+{
+       struct key *key;
+       struct task_security_struct *tsec;
+       struct key_security_struct *ksec;
+
+       key = key_ref_to_ptr(key_ref);
+
+       tsec = ctx->security;
+       ksec = key->security;
+
+       /* if no specific permissions are requested, we skip the
+          permission check. No serious, additional covert channels
+          appear to be created. */
+       if (perm == 0)
+               return 0;
+
+       return avc_has_perm(tsec->sid, ksec->sid,
+                           SECCLASS_KEY, perm, NULL);
+}
+
+#endif
+
 static struct security_operations selinux_ops = {
        .ptrace =                       selinux_ptrace,
        .capget =                       selinux_capget,
@@ -4406,6 +4457,12 @@ static struct security_operations selinux_ops = {
        .xfrm_state_delete_security =   selinux_xfrm_state_delete,
        .xfrm_policy_lookup =           selinux_xfrm_policy_lookup,
 #endif
+
+#ifdef CONFIG_KEYS
+       .key_alloc =                    selinux_key_alloc,
+       .key_free =                     selinux_key_free,
+       .key_permission =               selinux_key_permission,
+#endif
 };
 
 static __init int selinux_init(void)
@@ -4441,6 +4498,13 @@ static __init int selinux_init(void)
        } else {
                printk(KERN_INFO "SELinux:  Starting in permissive mode\n");
        }
+
+#ifdef CONFIG_KEYS
+       /* Add security information to initial keyrings */
+       security_key_alloc(&root_user_keyring, current);
+       security_key_alloc(&root_session_keyring, current);
+#endif
+
        return 0;
 }