From 81cf85ae4f2dd5fa3e43021782aa72c4c85558e8 Mon Sep 17 00:00:00 2001
From: Yuntao Wang <ytcoode@gmail.com>
Date: Fri, 12 Apr 2024 16:17:32 +0800
Subject: [PATCH] init/main.c: Fix potential static_command_line memory
 overflow

commit 46dad3c1e57897ab9228332f03e1c14798d2d3b9 upstream.

We allocate memory of size 'xlen + strlen(boot_command_line) + 1' for
static_command_line, but the strings copied into static_command_line are
extra_command_line and command_line, rather than extra_command_line and
boot_command_line.

When strlen(command_line) > strlen(boot_command_line), static_command_line
will overflow.

This patch just recovers strlen(command_line) which was miss-consolidated
with strlen(boot_command_line) in the commit f5c7310ac73e ("init/main: add
checks for the return value of memblock_alloc*()")

Link: https://lore.kernel.org/all/20240412081733.35925-2-ytcoode@gmail.com/

Fixes: f5c7310ac73e ("init/main: add checks for the return value of memblock_alloc*()")
Cc: stable@vger.kernel.org
Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 init/main.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/init/main.c b/init/main.c
index 9e6ab6d593bd..b25c779e93ac 100644
--- a/init/main.c
+++ b/init/main.c
@@ -630,6 +630,8 @@ static void __init setup_command_line(char *command_line)
 	if (!saved_command_line)
 		panic("%s: Failed to allocate %zu bytes\n", __func__, len + ilen);
 
+	len = xlen + strlen(command_line) + 1;
+
 	static_command_line = memblock_alloc(len, SMP_CACHE_BYTES);
 	if (!static_command_line)
 		panic("%s: Failed to allocate %zu bytes\n", __func__, len);