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>

diff --git a/init/main.c b/init/main.c
index 9e6ab6d593bd8e88b5d9d78a1ad6a7ca8c4470ce..b25c779e93ac43914c8bf27e3fac1799b02d69e4 100644 (file)
--- 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);