From e9f2c09012aec5c5a58b6c20a187d5de08b2565b Mon Sep 17 00:00:00 2001
From: ClawSeven <zehuan97@gmail.com>
Date: Mon, 29 Jan 2024 15:49:39 +0800
Subject: [PATCH] [libos] Fix readlinkat with non-positive bufsize

---
 src/libos/src/fs/syscalls.rs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/libos/src/fs/syscalls.rs b/src/libos/src/fs/syscalls.rs
index 3e21aece..35b495de 100644
--- a/src/libos/src/fs/syscalls.rs
+++ b/src/libos/src/fs/syscalls.rs
@@ -559,6 +559,9 @@ pub fn do_readlinkat(dirfd: i32, path: *const i8, buf: *mut u8, size: usize) ->
         .to_string_lossy()
         .into_owned();
     let buf = {
+        if size == 0 {
+            return_errno!(EINVAL, "bufsiz is not a positive number");
+        }
         from_user::check_array(buf, size)?;
         unsafe { std::slice::from_raw_parts_mut(buf, size) }
     };