Smack: update for file capabilities
Casey Schaufler [Sat, 23 Feb 2008 23:24:04 +0000 (15:24 -0800)]
Update the Smack LSM to allow the registration of the capability "module"
as a secondary LSM.  Integrate the new hooks required for file based
capabilities.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Paul Moore <paul.moore@hp.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

security/smack/smack_lsm.c

index 25cbfa3..770eb06 100644 (file)
@@ -584,14 +584,20 @@ static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
 static int smack_inode_setxattr(struct dentry *dentry, char *name,
                                void *value, size_t size, int flags)
 {
-       if (!capable(CAP_MAC_ADMIN)) {
-               if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
-                   strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
-                   strcmp(name, XATTR_NAME_SMACKIPOUT) == 0)
-                       return -EPERM;
-       }
+       int rc = 0;
 
-       return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE);
+       if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
+           strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
+           strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) {
+               if (!capable(CAP_MAC_ADMIN))
+                       rc = -EPERM;
+       } else
+               rc = cap_inode_setxattr(dentry, name, value, size, flags);
+
+       if (rc == 0)
+               rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE);
+
+       return rc;
 }
 
 /**
@@ -658,10 +664,20 @@ static int smack_inode_getxattr(struct dentry *dentry, char *name)
  */
 static int smack_inode_removexattr(struct dentry *dentry, char *name)
 {
-       if (strcmp(name, XATTR_NAME_SMACK) == 0 && !capable(CAP_MAC_ADMIN))
-               return -EPERM;
+       int rc = 0;
 
-       return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE);
+       if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
+           strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
+           strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) {
+               if (!capable(CAP_MAC_ADMIN))
+                       rc = -EPERM;
+       } else
+               rc = cap_inode_removexattr(dentry, name);
+
+       if (rc == 0)
+               rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE);
+
+       return rc;
 }
 
 /**
@@ -1016,7 +1032,12 @@ static void smack_task_getsecid(struct task_struct *p, u32 *secid)
  */
 static int smack_task_setnice(struct task_struct *p, int nice)
 {
-       return smk_curacc(p->security, MAY_WRITE);
+       int rc;
+
+       rc = cap_task_setnice(p, nice);
+       if (rc == 0)
+               rc = smk_curacc(p->security, MAY_WRITE);
+       return rc;
 }
 
 /**
@@ -1028,7 +1049,12 @@ static int smack_task_setnice(struct task_struct *p, int nice)
  */
 static int smack_task_setioprio(struct task_struct *p, int ioprio)
 {
-       return smk_curacc(p->security, MAY_WRITE);
+       int rc;
+
+       rc = cap_task_setioprio(p, ioprio);
+       if (rc == 0)
+               rc = smk_curacc(p->security, MAY_WRITE);
+       return rc;
 }
 
 /**
@@ -1053,7 +1079,12 @@ static int smack_task_getioprio(struct task_struct *p)
 static int smack_task_setscheduler(struct task_struct *p, int policy,
                                   struct sched_param *lp)
 {
-       return smk_curacc(p->security, MAY_WRITE);
+       int rc;
+
+       rc = cap_task_setscheduler(p, policy, lp);
+       if (rc == 0)
+               rc = smk_curacc(p->security, MAY_WRITE);
+       return rc;
 }
 
 /**
@@ -1093,6 +1124,11 @@ static int smack_task_movememory(struct task_struct *p)
 static int smack_task_kill(struct task_struct *p, struct siginfo *info,
                           int sig, u32 secid)
 {
+       int rc;
+
+       rc = cap_task_kill(p, info, sig, secid);
+       if (rc != 0)
+               return rc;
        /*
         * Special cases where signals really ought to go through
         * in spite of policy. Stephen Smalley suggests it may
@@ -1778,6 +1814,27 @@ static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
        return smk_curacc(isp, may);
 }
 
+/* module stacking operations */
+
+/**
+ * smack_register_security - stack capability module
+ * @name: module name
+ * @ops: module operations - ignored
+ *
+ * Allow the capability module to register.
+ */
+static int smack_register_security(const char *name,
+                                  struct security_operations *ops)
+{
+       if (strcmp(name, "capability") != 0)
+               return -EINVAL;
+
+       printk(KERN_INFO "%s:  Registering secondary module %s\n",
+              __func__, name);
+
+       return 0;
+}
+
 /**
  * smack_d_instantiate - Make sure the blob is correct on an inode
  * @opt_dentry: unused
@@ -2412,6 +2469,8 @@ static struct security_operations smack_ops = {
        .inode_post_setxattr =          smack_inode_post_setxattr,
        .inode_getxattr =               smack_inode_getxattr,
        .inode_removexattr =            smack_inode_removexattr,
+       .inode_need_killpriv =          cap_inode_need_killpriv,
+       .inode_killpriv =               cap_inode_killpriv,
        .inode_getsecurity =            smack_inode_getsecurity,
        .inode_setsecurity =            smack_inode_setsecurity,
        .inode_listsecurity =           smack_inode_listsecurity,
@@ -2471,6 +2530,8 @@ static struct security_operations smack_ops = {
        .netlink_send =                 cap_netlink_send,
        .netlink_recv =                 cap_netlink_recv,
 
+       .register_security =            smack_register_security,
+
        .d_instantiate =                smack_d_instantiate,
 
        .getprocattr =                  smack_getprocattr,