From 671a17abd90757bbadf02a5d7468c6f6910809ba Mon Sep 17 00:00:00 2001
From: Himbeer <himbeer@disroot.org>
Date: Thu, 1 Aug 2024 12:12:17 +0200
Subject: process: Ensure that ELF doesn't map important kernel memory

---
 src/lib/process.zig | 4 ++++
 1 file changed, 4 insertions(+)

(limited to 'src/lib/process.zig')

diff --git a/src/lib/process.zig b/src/lib/process.zig
index 265d9b3..b59d255 100644
--- a/src/lib/process.zig
+++ b/src/lib/process.zig
@@ -31,6 +31,7 @@ pub const ExeError = error{
     BadBitLen,
     NotStaticExe,
     LengthOutOfBounds,
+    ReservedMemMapping,
     BranchPerms,
     WritableCode,
 };
@@ -275,6 +276,9 @@ pub fn create(allocator: Allocator, elf_buf: []align(@alignOf(elf.Elf64_Ehdr)) c
                 .dirty = @bitCast(phdr.p_flags & elf.PF_W != 0),
             };
 
+            if (vaddr >= @intFromPtr(paging.text_start) and vaddr < paging.alloc_start) {
+                return ExeError.ReservedMemMapping;
+            }
             if (!@bitCast(flags.read) and !@bitCast(flags.write) and !@bitCast(flags.exec)) {
                 return ExeError.BranchPerms;
             }
-- 
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