From 41e1819072aeb448e767d41b61d5ed10de599097 Mon Sep 17 00:00:00 2001
From: Bananymous <oskari.alaranta@bananymous.com>
Date: Tue, 1 Jul 2025 14:20:09 +0300
Subject: [PATCH] Kernel: Align argv and envp to pointer boundary

This bug was found with ubsan
---
 kernel/kernel/Thread.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/kernel/Thread.cpp b/kernel/kernel/Thread.cpp
index f1a54ed6..de2f81e6 100644
--- a/kernel/kernel/Thread.cpp
+++ b/kernel/kernel/Thread.cpp
@@ -285,6 +285,9 @@ namespace Kernel
 		// auxv
 		needed_size += auxv.size() * sizeof(LibELF::AuxiliaryVector);
 
+		if (auto rem = needed_size % alignof(char*))
+			needed_size += alignof(char*) - rem;
+
 		if (needed_size > m_userspace_stack->size())
 			return BAN::Error::from_errno(ENOBUFS);
 
@@ -358,8 +361,6 @@ namespace Kernel
 			stack_push_str(envp[i]);
 		}
 
-		ASSERT(vaddr == userspace_stack_top());
-
 		setup_exec(entry, userspace_stack_top() - needed_size);
 
 		return {};