diff --git a/crate/memory/src/memory_set/mod.rs b/crate/memory/src/memory_set/mod.rs
index 63c9946..4bc7afb 100644
--- a/crate/memory/src/memory_set/mod.rs
+++ b/crate/memory/src/memory_set/mod.rs
@@ -72,7 +72,7 @@ impl MemoryArea {
             .map(|s| String::from(s))
     }
     /// Test whether this area is (page) overlap with area [`start_addr`, `end_addr`]
-    fn is_overlap_with(&self, start_addr: VirtAddr, end_addr: VirtAddr) -> bool {
+    pub fn is_overlap_with(&self, start_addr: VirtAddr, end_addr: VirtAddr) -> bool {
         let p0 = Page::of_addr(self.start_addr);
         let p1 = Page::of_addr(self.end_addr - 1) + 1;
         let p2 = Page::of_addr(start_addr);
diff --git a/kernel/src/syscall/mem.rs b/kernel/src/syscall/mem.rs
index 986e56c..457131f 100644
--- a/kernel/src/syscall/mem.rs
+++ b/kernel/src/syscall/mem.rs
@@ -84,7 +84,7 @@ pub fn sys_mprotect(addr: usize, len: usize, prot: usize) -> SysResult {
 
     // FIXME: properly set the attribute of the area
     //        now some mut ptr check is fault
-    let memory_area = proc.vm.iter().find(|area| area.contains(addr));
+    let memory_area = proc.vm.iter().find(|area| area.is_overlap_with(addr, addr + len));
     if memory_area.is_none() {
         return Err(SysError::ENOMEM);
     }
diff --git a/user b/user
index 4bcc820..835568e 160000
--- a/user
+++ b/user
@@ -1 +1 @@
-Subproject commit 4bcc820a8b316c177cc5d82ee5edbbe0ac551814
+Subproject commit 835568e2059ef872320e41517e826ced0768e357