[PATCH 5.15 62/71] init/main.c: Fix potential static_command_line memory overflow

Greg Kroah-Hartman
2024-04-23T21:46:43Z

From: Yuntao Wang <ytcoode@gmail.com>

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(+)

--- a/init/main.c
+++ b/init/main.c
@@ -640,6 +640,8 @@ static void __init setup_command_line(ch
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);