Merge master.kernel.org:/home/rmk/linux-2.6-arm

[sfrench/cifs-2.6.git] / security / smack / smackfs.c

diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index 15aa37f65b399a87146fdc8eb88da937f9beb1c4..afe7c9b0732ac6c16ae6677bbfe1ca0ca5ecf799 100644 (file)
--- 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.
@@ -79,10 +81,23 @@ static struct semaphore smack_write_sem;
 /*
  * Values for parsing cipso rules
  * SMK_DIGITLEN: Length of a digit field in a rule.
- * SMK_CIPSOMEN: Minimum possible cipso rule length.
+ * SMK_CIPSOMIN: Minimum possible cipso rule length.
+ * SMK_CIPSOMAX: Maximum possible cipso rule length.
  */
 #define SMK_DIGITLEN 4
-#define SMK_CIPSOMIN (SMK_MAXLEN + 2 * SMK_DIGITLEN)
+#define SMK_CIPSOMIN (SMK_LABELLEN + 2 * SMK_DIGITLEN)
+#define SMK_CIPSOMAX (SMK_CIPSOMIN + SMACK_CIPSO_MAXCATNUM * SMK_DIGITLEN)
+
+/*
+ * Values for parsing MAC rules
+ * SMK_ACCESS: Maximum possible combination of access permissions
+ * SMK_ACCESSLEN: Maximum length for a rule access field
+ * SMK_LOADLEN: Smack rule length
+ */
+#define SMK_ACCESS    "rwxa"
+#define SMK_ACCESSLEN (sizeof(SMK_ACCESS) - 1)
+#define SMK_LOADLEN   (SMK_LABELLEN + SMK_LABELLEN + SMK_ACCESSLEN)
+
 
 /*
  * Seq_file read operations for /smack/load
@@ -227,14 +242,10 @@ static void smk_set_access(struct smack_rule *srp)
  * The format is exactly:
  *     char subject[SMK_LABELLEN]
  *     char object[SMK_LABELLEN]
- *     char access[SMK_ACCESSKINDS]
+ *     char access[SMK_ACCESSLEN]
  *
- *     Anything following is commentary and ignored.
- *
- * writes must be SMK_LABELLEN+SMK_LABELLEN+4 bytes.
+ * writes must be SMK_LABELLEN+SMK_LABELLEN+SMK_ACCESSLEN bytes.
  */
-#define MINIMUM_LOAD (SMK_LABELLEN + SMK_LABELLEN + SMK_ACCESSKINDS)
-
 static ssize_t smk_write_load(struct file *file, const char __user *buf,
                              size_t count, loff_t *ppos)
 {
@@ -251,7 +262,7 @@ static ssize_t smk_write_load(struct file *file, const char __user *buf,
                return -EPERM;
        if (*ppos != 0)
                return -EINVAL;
-       if (count < MINIMUM_LOAD)
+       if (count != SMK_LOADLEN)
                return -EINVAL;
 
        data = kzalloc(count, GFP_KERNEL);
@@ -342,6 +353,9 @@ 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 +377,30 @@ 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
  */
@@ -484,7 +522,7 @@ static ssize_t smk_write_cipso(struct file *file, const char __user *buf,
                return -EPERM;
        if (*ppos != 0)
                return -EINVAL;
-       if (count <= SMK_CIPSOMIN)
+       if (count < SMK_CIPSOMIN || count > SMK_CIPSOMAX)
                return -EINVAL;
 
        data = kzalloc(count + 1, GFP_KERNEL);
@@ -518,7 +556,7 @@ static ssize_t smk_write_cipso(struct file *file, const char __user *buf,
        if (ret != 1 || catlen > SMACK_CIPSO_MAXCATNUM)
                goto out;
 
-       if (count <= (SMK_CIPSOMIN + catlen * SMK_DIGITLEN))
+       if (count != (SMK_CIPSOMIN + catlen * SMK_DIGITLEN))
                goto out;
 
        memset(mapcatset, 0, sizeof(mapcatset));
@@ -709,7 +747,6 @@ 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 +754,18 @@ 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 +783,7 @@ 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 +799,13 @@ 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 +1013,7 @@ static int __init init_smk_fs(void)
 
        sema_init(&smack_write_sem, 1);
        smk_cipso_doi();
+       smk_unlbl_ambient(NULL);
 
        return err;
 }