From f27bbec7b285e7aa93b230ee4bd55fa631f88ff8 Mon Sep 17 00:00:00 2001
From: Idan Horowitz <idan.horowitz@gmail.com>
Date: Wed, 1 Dec 2021 19:20:52 +0200
Subject: [PATCH] Kernel: Move incorrect early return in sys$mprotect

Since we're iterating over multiple regions that interesect with the
requested range, just one of them having the requested access flags
is not enough to finish the syscall early.
---
 Kernel/Syscalls/mmap.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/Kernel/Syscalls/mmap.cpp b/Kernel/Syscalls/mmap.cpp
index 4d2856fab8..065c8add69 100644
--- a/Kernel/Syscalls/mmap.cpp
+++ b/Kernel/Syscalls/mmap.cpp
@@ -331,8 +331,6 @@ ErrorOr<FlatPtr> Process::sys$mprotect(Userspace<void*> addr, size_t size, int p
                 return EPERM;
             if (!validate_mmap_prot(prot, region->is_stack(), region->vmobject().is_anonymous(), region))
                 return EINVAL;
-            if (region->access() == Memory::prot_to_region_access_flags(prot))
-                return 0;
             if (region->vmobject().is_inode()
                 && !validate_inode_mmap_prot(*this, prot, static_cast<Memory::InodeVMObject const&>(region->vmobject()).inode(), region->is_shared())) {
                 return EACCES;
@@ -345,6 +343,9 @@ ErrorOr<FlatPtr> Process::sys$mprotect(Userspace<void*> addr, size_t size, int p
 
         // then do all the other stuff
         for (auto* old_region : regions) {
+            if (old_region->access() == Memory::prot_to_region_access_flags(prot))
+                continue;
+
             const auto intersection_to_mprotect = range_to_mprotect.intersect(old_region->range());
             // full sub region
             if (intersection_to_mprotect == old_region->range()) {