lsm: Refactor return value of LSM hook vm_enough_memory

To be consistent with most LSM hooks, convert the return value of
hook vm_enough_memory to 0 or a negative error code.

Before:
- Hook vm_enough_memory returns 1 if permission is granted, 0 if not.
- LSM_RET_DEFAULT(vm_enough_memory_mm) is 1.

After:
- Hook vm_enough_memory reutrns 0 if permission is granted, negative
  error code if not.
- LSM_RET_DEFAULT(vm_enough_memory_mm) is 0.

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

1 files changed, 3 insertions, 8 deletions

diff --git a/security/commoncap.c b/security/commoncap.c
index 162d96b3a676..cefad323a0b1 100644
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -1396,17 +1396,12 @@ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3,
  * Determine whether the allocation of a new virtual mapping by the current
  * task is permitted.
  *
- * Return: 1 if permission is granted, 0 if not.
+ * Return: 0 if permission granted, negative error code if not.
  */
 int cap_vm_enough_memory(struct mm_struct *mm, long pages)
 {
-	int cap_sys_admin = 0;
-
-	if (cap_capable(current_cred(), &init_user_ns,
-				CAP_SYS_ADMIN, CAP_OPT_NOAUDIT) == 0)
-		cap_sys_admin = 1;
-
-	return cap_sys_admin;
+	return cap_capable(current_cred(), &init_user_ns, CAP_SYS_ADMIN,
+			   CAP_OPT_NOAUDIT);
 }
 
 /**