selinux: convert type_val_to_struct to flex_array
In rawhide type_val_to_struct will allocate 26848 bytes, an order 3
allocations. While this hasn't been seen to fail it isn't outside the
realm of possibiliy on systems with severe memory fragmentation. Convert
to flex_array so no allocation will ever be bigger than PAGE_SIZE.
Signed-off-by: Eric Paris <eparis@redhat.com>
diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c
index 6ad73e8..af41fdf 100644
--- a/security/selinux/ss/policydb.c
+++ b/security/selinux/ss/policydb.c
@@ -307,7 +307,11 @@
|| typdatum->bounds > p->p_types.nprim)
return -EINVAL;
p->p_type_val_to_name[typdatum->value - 1] = key;
- p->type_val_to_struct[typdatum->value - 1] = typdatum;
+ /* this flex array was all preallocated, this cannot fail */
+ if (flex_array_put_ptr(p->type_val_to_struct_array,
+ typdatum->value - 1, typdatum,
+ GFP_KERNEL | __GFP_ZERO))
+ BUG();
}
return 0;
@@ -484,11 +488,17 @@
if (!p->user_val_to_struct)
goto out;
+ /* Yes, I want the sizeof the pointer, not the structure */
rc = -ENOMEM;
- p->type_val_to_struct =
- kmalloc(p->p_types.nprim * sizeof(*(p->type_val_to_struct)),
- GFP_KERNEL);
- if (!p->type_val_to_struct)
+ p->type_val_to_struct_array = flex_array_alloc(sizeof(struct type_datum *),
+ p->p_types.nprim,
+ GFP_KERNEL | __GFP_ZERO);
+ if (!p->type_val_to_struct_array)
+ goto out;
+
+ rc = flex_array_prealloc(p->type_val_to_struct_array, 0,
+ p->p_types.nprim - 1, GFP_KERNEL | __GFP_ZERO);
+ if (rc)
goto out;
rc = -ENOMEM;
@@ -699,7 +709,8 @@
kfree(p->class_val_to_struct);
kfree(p->role_val_to_struct);
kfree(p->user_val_to_struct);
- kfree(p->type_val_to_struct);
+ if (p->type_val_to_struct_array)
+ flex_array_free(p->type_val_to_struct_array);
avtab_destroy(&p->te_avtab);
@@ -1618,7 +1629,10 @@
return -EINVAL;
}
- upper = p->type_val_to_struct[upper->bounds - 1];
+ upper = flex_array_get_ptr(p->type_val_to_struct_array,
+ upper->bounds - 1);
+ BUG_ON(!upper);
+
if (upper->attribute) {
printk(KERN_ERR "SELinux: type %s: "
"bounded by attribute %s",