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From: Yuntao Wang <ytcoode@gmail.com>
To: mhiramat@kernel.org
Cc: akpm@linux-foundation.org,
	arnd@arndb.de,
	christophe.leroy@csgroup.eu,
	geert@linux-m68k.org,
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	tglx@linutronix.de,
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	ytcoode@gmail.com
Subject: [PATCH v2 1/2] init/main.c: Fix potential static_command_line memory overflow
Date: Fri, 12 Apr 2024 16:17:32 +0800
Message-ID: <20240412081733.35925-2-ytcoode@gmail.com>
In-Reply-To: <20240412081733.35925-1-ytcoode@gmail.com>
References: <20240412141536.3f59fde391a6d28181562dbe@kernel.org>
 <20240412081733.35925-1-ytcoode@gmail.com>
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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*()")

Fixes: f5c7310ac73e ("init/main: add checks for the return value of memblock_alloc*()")
Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
---
 init/main.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/init/main.c b/init/main.c
index 881f6230ee59..5dcf5274c09c 100644
--- a/init/main.c
+++ b/init/main.c
@@ -636,6 +636,8 @@ 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);
-- 
2.44.0