1 files changed, 46 insertions, 15 deletions

diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index 15aa37f65b39..358c92c1a153 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -24,6 +24,7 @@
 #include <net/cipso_ipv4.h>
 #include <linux/seq_file.h>
 #include <linux/ctype.h>
+#include <linux/audit.h>
 #include "smack.h"
 
 /*
@@ -45,6 +46,7 @@ enum smk_inos {
  */
 static DEFINE_MUTEX(smack_list_lock);
 static DEFINE_MUTEX(smack_cipso_lock);
+static DEFINE_MUTEX(smack_ambient_lock);
 
 /*
  * This is the "ambient" label for network traffic.
@@ -342,6 +344,9 @@ void smk_cipso_doi(void)
         struct cipso_v4_doi *doip;
         struct netlbl_audit audit_info;
 
+        audit_info.loginuid = audit_get_loginuid(current);
+        audit_info.secid = smack_to_secid(current->security);
+
         rc = netlbl_cfg_map_del(NULL, &audit_info);
         if (rc != 0)
                 printk(KERN_WARNING "%s:%d remove rc = %d\n",
@@ -363,6 +368,30 @@ void smk_cipso_doi(void)
                        __func__, __LINE__, rc);
 }
 
+/**
+ * smk_unlbl_ambient - initialize the unlabeled domain
+ */
+void smk_unlbl_ambient(char *oldambient)
+{
+        int rc;
+        struct netlbl_audit audit_info;
+
+        audit_info.loginuid = audit_get_loginuid(current);
+        audit_info.secid = smack_to_secid(current->security);
+
+        if (oldambient != NULL) {
+                rc = netlbl_cfg_map_del(oldambient, &audit_info);
+                if (rc != 0)
+                        printk(KERN_WARNING "%s:%d remove rc = %d\n",
+                               __func__, __LINE__, rc);
+        }
+
+        rc = netlbl_cfg_unlbl_add_map(smack_net_ambient, &audit_info);
+        if (rc != 0)
+                printk(KERN_WARNING "%s:%d add rc = %d\n",
+                       __func__, __LINE__, rc);
+}
+
 /*
  * Seq_file read operations for /smack/cipso
  */
@@ -709,7 +738,6 @@ static ssize_t smk_read_ambient(struct file *filp, char __user *buf,
                                 size_t cn, loff_t *ppos)
 {
         ssize_t rc;
-        char out[SMK_LABELLEN];
         int asize;
 
         if (*ppos != 0)
@@ -717,23 +745,18 @@ static ssize_t smk_read_ambient(struct file *filp, char __user *buf,
         /*
          * Being careful to avoid a problem in the case where
          * smack_net_ambient gets changed in midstream.
-         * Since smack_net_ambient is always set with a value
-         * from the label list, including initially, and those
-         * never get freed, the worst case is that the pointer
-         * gets changed just after this strncpy, in which case
-         * the value passed up is incorrect. Locking around
-         * smack_net_ambient wouldn't be any better than this
-         * copy scheme as by the time the caller got to look
-         * at the ambient value it would have cleared the lock
-         * and been changed.
          */
-        strncpy(out, smack_net_ambient, SMK_LABELLEN);
-        asize = strlen(out) + 1;
+        mutex_lock(&smack_ambient_lock);
 
-        if (cn < asize)
-                return -EINVAL;
+        asize = strlen(smack_net_ambient) + 1;
+
+        if (cn >= asize)
+                rc = simple_read_from_buffer(buf, cn, ppos,
+                                             smack_net_ambient, asize);
+        else
+                rc = -EINVAL;
 
-        rc = simple_read_from_buffer(buf, cn, ppos, out, asize);
+        mutex_unlock(&smack_ambient_lock);
 
         return rc;
 }
@@ -751,6 +774,7 @@ static ssize_t smk_write_ambient(struct file *file, const char __user *buf,
                                  size_t count, loff_t *ppos)
 {
         char in[SMK_LABELLEN];
+        char *oldambient;
         char *smack;
 
         if (!capable(CAP_MAC_ADMIN))
@@ -766,7 +790,13 @@ static ssize_t smk_write_ambient(struct file *file, const char __user *buf,
         if (smack == NULL)
                 return -EINVAL;
 
+        mutex_lock(&smack_ambient_lock);
+
+        oldambient = smack_net_ambient;
         smack_net_ambient = smack;
+        smk_unlbl_ambient(oldambient);
+
+        mutex_unlock(&smack_ambient_lock);
 
         return count;
 }
@@ -974,6 +1004,7 @@ static int __init init_smk_fs(void)
 
         sema_init(&smack_write_sem, 1);
         smk_cipso_doi();
+        smk_unlbl_ambient(NULL);
 
         return err;
 }