fixup: memory leak

Author: dlon

talpid-windows/src/fs.rs

@@ -1,18 +1,20 @@
+use core::ffi::c_void;
 use std::io;
 use std::os::windows::io::AsRawHandle;
 use std::ptr;
 
 use windows_sys::Win32::{
-    Foundation::ERROR_SUCCESS,
+    Foundation::{LocalFree, ERROR_SUCCESS},
     Security::{
         Authorization::{GetSecurityInfo, SE_FILE_OBJECT},
         IsWellKnownSid, WinBuiltinAdministratorsSid, WinLocalSystemSid, OWNER_SECURITY_INFORMATION,
-        SID,
+        SECURITY_DESCRIPTOR, SID,
     },
 };
 
 /// Return whether a file handle is owned by either SYSTEM or the built-in administrators account
 pub fn is_admin_owned<T: AsRawHandle>(handle: T) -> io::Result<bool> {
+    let mut security_descriptor: *mut SECURITY_DESCRIPTOR = ptr::null_mut();
     let mut owner: *mut SID = ptr::null_mut();
 
     // SAFETY: `handle` is a valid handle. We return a pointer to the owner associated with the handle(?)
@@ -21,22 +23,25 @@ pub fn is_admin_owned<T: AsRawHandle>(handle: T) -> io::Result<bool> {
             handle.as_raw_handle() as isize,
             SE_FILE_OBJECT,
             OWNER_SECURITY_INFORMATION,
-            (&mut owner) as *mut *mut SID as _,
-            ptr::null_mut(),
+            (&mut owner) as *mut *mut SID as *mut *mut c_void,
             ptr::null_mut(),
             ptr::null_mut(),
             ptr::null_mut(),
+            (&mut security_descriptor) as *mut *mut SECURITY_DESCRIPTOR as *mut *mut c_void,
         )
     };
 
     if result != ERROR_SUCCESS {
         return Err(io::Error::from_raw_os_error(result as i32));
     }
 
-    Ok(
-        // SAFETY: `owner` is valid, and the well-known type is a valid argument
-        unsafe { IsWellKnownSid(owner as _, WinBuiltinAdministratorsSid) != 0 } ||
-        // SAFETY: `owner` is valid, and the well-known type is a valid argument
-        unsafe { IsWellKnownSid(owner as _, WinLocalSystemSid) != 0 },
-    )
+    // SAFETY: `owner` is valid since `security_descriptor` still is, and the well-known type is a valid argument
+    let is_system_owned = unsafe { IsWellKnownSid(owner as _, WinLocalSystemSid) != 0 };
+    // SAFETY: `owner` is valid since `security_descriptor` still is, and the well-known type is a valid argument
+    let is_admin_owned = unsafe { IsWellKnownSid(owner as _, WinBuiltinAdministratorsSid) != 0 };
+
+    // SAFETY: Since we no longer need the descriptor (or owner), it may be freed
+    unsafe { LocalFree(security_descriptor.cast()) };
+
+    Ok(is_system_owned || is_admin_owned)
 }