1 files changed, 50 insertions, 24 deletions

diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 7e19afe0e738..05dc4da2e25f 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3,12 +3,14 @@
  *
  *  This file contains the smack hook function implementations.
  *
- *  Author:
+ *  Authors:
  *      Casey Schaufler <casey@schaufler-ca.com>
+ *      Jarkko Sakkinen <ext-jarkko.2.sakkinen@nokia.com>
  *
  *  Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
  *  Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
  *                Paul Moore <paul.moore@hp.com>
+ *  Copyright (C) 2010 Nokia Corporation
  *
  *      This program is free software; you can redistribute it and/or modify
  *      it under the terms of the GNU General Public License version 2,
@@ -35,6 +37,9 @@
 
 #define task_security(task)     (task_cred_xxx((task), security))
 
+#define TRANS_TRUE      "TRUE"
+#define TRANS_TRUE_SIZE 4
+
 /**
  * smk_fetch - Fetch the smack label from a file.
  * @ip: a pointer to the inode
@@ -468,6 +473,8 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir,
                                      char **name, void **value, size_t *len)
 {
         char *isp = smk_of_inode(inode);
+        char *dsp = smk_of_inode(dir);
+        u32 may;
 
         if (name) {
                 *name = kstrdup(XATTR_SMACK_SUFFIX, GFP_KERNEL);
@@ -476,6 +483,16 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir,
         }
 
         if (value) {
+                may = smk_access_entry(smk_of_current(), dsp);
+
+                /*
+                 * If the access rule allows transmutation and
+                 * the directory requests transmutation then
+                 * by all means transmute.
+                 */
+                if (((may & MAY_TRANSMUTE) != 0) && smk_inode_transmutable(dir))
+                        isp = dsp;
+
                 *value = kstrdup(isp, GFP_KERNEL);
                 if (*value == NULL)
                         return -ENOMEM;
@@ -709,6 +726,12 @@ static int smack_inode_setxattr(struct dentry *dentry, const char *name,
                 if (size == 0 || size >= SMK_LABELLEN ||
                     smk_import(value, size) == NULL)
                         rc = -EINVAL;
+        } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
+                if (!capable(CAP_MAC_ADMIN))
+                        rc = -EPERM;
+                if (size != TRANS_TRUE_SIZE ||
+                    strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0)
+                        rc = -EINVAL;
         } else
                 rc = cap_inode_setxattr(dentry, name, value, size, flags);
 
@@ -735,35 +758,23 @@ static int smack_inode_setxattr(struct dentry *dentry, const char *name,
 static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
                                       const void *value, size_t size, int flags)
 {
-        struct inode_smack *isp;
         char *nsp;
-
-        /*
-         * Not SMACK or SMACKEXEC
-         */
-        if (strcmp(name, XATTR_NAME_SMACK) &&
-            strcmp(name, XATTR_NAME_SMACKEXEC))
-                return;
-
-        isp = dentry->d_inode->i_security;
-
-        /*
-         * No locking is done here. This is a pointer
-         * assignment.
-         */
-        nsp = smk_import(value, size);
+        struct inode_smack *isp = dentry->d_inode->i_security;
 
         if (strcmp(name, XATTR_NAME_SMACK) == 0) {
+                nsp = smk_import(value, size);
                 if (nsp != NULL)
                         isp->smk_inode = nsp;
                 else
                         isp->smk_inode = smack_known_invalid.smk_known;
-        } else {
+        } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) {
+                nsp = smk_import(value, size);
                 if (nsp != NULL)
                         isp->smk_task = nsp;
                 else
                         isp->smk_task = smack_known_invalid.smk_known;
-        }
+        } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0)
+                isp->smk_flags |= SMK_INODE_TRANSMUTE;
 
         return;
 }
@@ -803,7 +814,8 @@ static int smack_inode_removexattr(struct dentry *dentry, const char *name)
         if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
             strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
             strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
-            strcmp(name, XATTR_NAME_SMACKEXEC) == 0) {
+            strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
+            strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
                 if (!capable(CAP_MAC_ADMIN))
                         rc = -EPERM;
         } else
@@ -2274,6 +2286,8 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
         char *csp = smk_of_current();
         char *fetched;
         char *final;
+        char trattr[TRANS_TRUE_SIZE];
+        int transflag = 0;
         struct dentry *dp;
 
         if (inode == NULL)
@@ -2392,10 +2406,19 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
                  */
                 dp = dget(opt_dentry);
                 fetched = smk_fetch(XATTR_NAME_SMACK, inode, dp);
-                if (fetched != NULL)
+                if (fetched != NULL) {
                         final = fetched;
-                isp->smk_task = smk_fetch(XATTR_NAME_SMACKEXEC, inode,
-                                          dp);
+                        if (S_ISDIR(inode->i_mode)) {
+                                trattr[0] = '\0';
+                                inode->i_op->getxattr(dp,
+                                        XATTR_NAME_SMACKTRANSMUTE,
+                                        trattr, TRANS_TRUE_SIZE);
+                                if (strncmp(trattr, TRANS_TRUE,
+                                            TRANS_TRUE_SIZE) == 0)
+                                        transflag = SMK_INODE_TRANSMUTE;
+                        }
+                }
+                isp->smk_task = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp);
 
                 dput(dp);
                 break;
@@ -2406,7 +2429,7 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
         else
                 isp->smk_inode = final;
 
-        isp->smk_flags |= SMK_INODE_INSTANT;
+        isp->smk_flags |= (SMK_INODE_INSTANT | transflag);
 
 unlockandout:
         mutex_unlock(&isp->smk_lock);
@@ -2456,6 +2479,7 @@ static int smack_setprocattr(struct task_struct *p, char *name,
                              void *value, size_t size)
 {
         struct task_smack *tsp;
+        struct task_smack *oldtsp;
         struct cred *new;
         char *newsmack;
 
@@ -2485,6 +2509,7 @@ static int smack_setprocattr(struct task_struct *p, char *name,
         if (newsmack == smack_known_web.smk_known)
                 return -EPERM;
 
+        oldtsp = p->cred->security;
         new = prepare_creds();
         if (new == NULL)
                 return -ENOMEM;
@@ -2494,6 +2519,7 @@ static int smack_setprocattr(struct task_struct *p, char *name,
                 return -ENOMEM;
         }
         tsp->smk_task = newsmack;
+        tsp->smk_forked = oldtsp->smk_forked;
         new->security = tsp;
         commit_creds(new);
         return size;