From de565c721a0ab9fb28c9a9e64a6098ce12201e14 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=D0=90=D1=80=D1=82=D1=91=D0=BC=20=D0=9F=D0=B0=D0=B2=D0=BB?=
 =?UTF-8?q?=D0=BE=D0=B2=20=5BArtyom=20Pavlov=5D?= <newpavlov@gmail.com>
Date: Fri, 27 Jan 2023 02:59:54 +0300
Subject: [PATCH] Eliminate potential panic in sys_fill_exact

---
 src/util_libc.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/util_libc.rs b/src/util_libc.rs
index bd9c7de1..de1455c5 100644
--- a/src/util_libc.rs
+++ b/src/util_libc.rs
@@ -8,6 +8,7 @@
 #![allow(dead_code)]
 use crate::Error;
 use core::{
+    cmp::min,
     mem::MaybeUninit,
     num::NonZeroU32,
     ptr::NonNull,
@@ -78,7 +79,8 @@ pub fn sys_fill_exact(
         } else {
             // We don't check for EOF (ret = 0) as the data we are reading
             // should be an infinite stream of random bytes.
-            buf = &mut buf[(res as usize)..];
+            let len = min(res as usize, buf.len());
+            buf = &mut buf[len..];
         }
     }
     Ok(())