selinux: fix error codes in cond_read_node()

Originally cond_read_node() returned -1 (-EPERM) on errors which was incorrect.  Now it either propagates the error codes from lower level functions next_entry() or cond_read_av_list() or it returns -ENOMEM or -EINVAL.

next_entry() returns -EINVAL.
cond_read_av_list() returns -EINVAL or -ENOMEM.

Signed-off-by Dan Carpenter <[email protected]>

security/selinux/ss/conditional.c +4 -2

index 4c39f19..f0de637 100644
@@ -392,14 +392,14 @@ static int cond_read_node(struct policydb *p, struct cond_node *node, void *fp)
 
        rc = next_entry(buf, fp, sizeof(u32));
        if (rc < 0)
-               return -1;
+               return rc;
 
        node->cur_state = le32_to_cpu(buf[0]);
 
        len = 0;
        rc = next_entry(buf, fp, sizeof(u32));
        if (rc < 0)
-               return -1;
+               return rc;
 
        /* expr */
        len = le32_to_cpu(buf[0]);

@@ -409,6 +409,7 @@ static int cond_read_node(struct policydb *p, struct cond_node *node, void *fp)
                if (rc < 0)
                        goto err;
 
+               rc = -ENOMEM;
                expr = kzalloc(sizeof(struct cond_expr), GFP_KERNEL);
                if (!expr)
                        goto err;

@@ -417,6 +418,7 @@ static int cond_read_node(struct policydb *p, struct cond_node *node, void *fp)
                expr->bool = le32_to_cpu(buf[1]);
 
                if (!expr_isvalid(p, expr)) {
+                       rc = -EINVAL;
                        kfree(expr);
                        goto err;
                }

@@ -428,14 +430,16 @@ static int cond_read_node(struct policydb *p, struct cond_node *node, void *fp)
                last = expr;

security/selinux/ss/conditional.c +0 -0

        return 0;

 err:
       cond_node_destroy(node);
-       return -1;
+       return rc;
 }

 int cond_read_list(struct policydb *p, void *fp)

Quoted 3 lines

+       rc = cond_read_av_list(p, fp, &node->false_list, node->true_list);
+       if (rc < 0)
               goto err;

I know that lots of the next_entry() calls use if (rc < 0) [unrelated note I think those need to be fixed too] but most of the code uses if (rc) and I strongly prefer if (rc) as it's cleaner and faster from a micro architecture point of view. Would you mind re-spinning this one?

-Eric