selinux: cleanup return codes in avtab_read_item()

The avtab_read_item() function tends to return -1 as a default error
code which is wrong (-1 means -EPERM).  I modified it to return
appropriate error codes which is -EINVAL or the error code from
next_entry() or insertf().

next_entry() returns -EINVAL.
insertf() is a function pointer to either avtab_insert() or
cond_insertf().
avtab_insert() returns -EINVAL, -ENOMEM, and -EEXIST.
cond_insertf() currently returns -1, but I will fix it in a later patch.

There is code in avtab_read() which translates the -1 returns from
avtab_read_item() to -EINVAL. The translation is no longer needed, so I
removed it.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by:  Stephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 19 insertions, 20 deletions

diff --git a/security/selinux/ss/avtab.c b/security/selinux/ss/avtab.c
index 1215b8e47dba..929480c6c430 100644
--- a/security/selinux/ss/avtab.c
+++ b/security/selinux/ss/avtab.c
@@ -342,20 +342,20 @@ int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol,
 
         if (vers < POLICYDB_VERSION_AVTAB) {
                 rc = next_entry(buf32, fp, sizeof(u32));
-                if (rc < 0) {
+                if (rc) {
                         printk(KERN_ERR "SELinux: avtab: truncated entry\n");
-                        return -1;
+                        return rc;
                 }
                 items2 = le32_to_cpu(buf32[0]);
                 if (items2 > ARRAY_SIZE(buf32)) {
                         printk(KERN_ERR "SELinux: avtab: entry overflow\n");
-                        return -1;
+                        return -EINVAL;
 
                 }
                 rc = next_entry(buf32, fp, sizeof(u32)*items2);
-                if (rc < 0) {
+                if (rc) {
                         printk(KERN_ERR "SELinux: avtab: truncated entry\n");
-                        return -1;
+                        return rc;
                 }
                 items = 0;
 
@@ -363,19 +363,19 @@ int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol,
                 key.source_type = (u16)val;
                 if (key.source_type != val) {
                         printk(KERN_ERR "SELinux: avtab: truncated source type\n");
-                        return -1;
+                        return -EINVAL;
                 }
                 val = le32_to_cpu(buf32[items++]);
                 key.target_type = (u16)val;
                 if (key.target_type != val) {
                         printk(KERN_ERR "SELinux: avtab: truncated target type\n");
-                        return -1;
+                        return -EINVAL;
                 }
                 val = le32_to_cpu(buf32[items++]);
                 key.target_class = (u16)val;
                 if (key.target_class != val) {
                         printk(KERN_ERR "SELinux: avtab: truncated target class\n");
-                        return -1;
+                        return -EINVAL;
                 }
 
                 val = le32_to_cpu(buf32[items++]);
@@ -383,12 +383,12 @@ int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol,
 
                 if (!(val & (AVTAB_AV | AVTAB_TYPE))) {
                         printk(KERN_ERR "SELinux: avtab: null entry\n");
-                        return -1;
+                        return -EINVAL;
                 }
                 if ((val & AVTAB_AV) &&
                     (val & AVTAB_TYPE)) {
                         printk(KERN_ERR "SELinux: avtab: entry has both access vectors and types\n");
-                        return -1;
+                        return -EINVAL;
                 }
 
                 for (i = 0; i < ARRAY_SIZE(spec_order); i++) {
@@ -403,15 +403,15 @@ int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol,
 
                 if (items != items2) {
                         printk(KERN_ERR "SELinux: avtab: entry only had %d items, expected %d\n", items2, items);
-                        return -1;
+                        return -EINVAL;
                 }
                 return 0;
         }
 
         rc = next_entry(buf16, fp, sizeof(u16)*4);
-        if (rc < 0) {
+        if (rc) {
                 printk(KERN_ERR "SELinux: avtab: truncated entry\n");
-                return -1;
+                return rc;
         }
 
         items = 0;
@@ -424,7 +424,7 @@ int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol,
             !policydb_type_isvalid(pol, key.target_type) ||
             !policydb_class_isvalid(pol, key.target_class)) {
                 printk(KERN_ERR "SELinux: avtab: invalid type or class\n");
-                return -1;
+                return -EINVAL;
         }
 
         set = 0;
@@ -434,19 +434,19 @@ int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol,
         }
         if (!set || set > 1) {
                 printk(KERN_ERR "SELinux:  avtab:  more than one specifier\n");
-                return -1;
+                return -EINVAL;
         }
 
         rc = next_entry(buf32, fp, sizeof(u32));
-        if (rc < 0) {
+        if (rc) {
                 printk(KERN_ERR "SELinux: avtab: truncated entry\n");
-                return -1;
+                return rc;
         }
         datum.data = le32_to_cpu(*buf32);
         if ((key.specified & AVTAB_TYPE) &&
             !policydb_type_isvalid(pol, datum.data)) {
                 printk(KERN_ERR "SELinux: avtab: invalid type\n");
-                return -1;
+                return -EINVAL;
         }
         return insertf(a, &key, &datum, p);
 }
@@ -487,8 +487,7 @@ int avtab_read(struct avtab *a, void *fp, struct policydb *pol)
                                 printk(KERN_ERR "SELinux: avtab: out of memory\n");
                         else if (rc == -EEXIST)
                                 printk(KERN_ERR "SELinux: avtab: duplicate entry\n");
-                        else
-                                rc = -EINVAL;
+
                         goto bad;
                 }
         }