[BUG] execve("/bin/sh"...) in init/main.c

From: Eric Swalens <eric.swalens@easynet.be>
To: linux-kernel@vger.kernel.org
Subject: [BUG] execve("/bin/sh"...) in init/main.c
Date: Wed, 27 Feb 2002 21:21:39 +0100	[thread overview]
Message-ID: <E16gAZm-0000W3-00@bigglesworth.mail.be.easynet.net> (raw)

If init cannot be executed, the init(.) function in init/main.c falls back to 
sh and calls execve("/bin/sh", argv_init, envp_init).

But if there is no "init=" in the command line, argv_init can contain 
something (most likely the "auto" preprended by lilo) and the shell will 
terminate immediately. (parse_options(.) does not handle this case since it 
does not find "init=").

I used the simple patch below to correct the problem.

Eric

--- linux-2.4.18/init/main.c    Mon Feb 25 20:38:13 2002
+++ linux/init/main.c   Wed Feb 27 18:46:51 2002
@@ -130,6 +130,7 @@
 char root_device_name[64];


+static char * argv_sh[2] = { "sh", NULL };
 static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
 static char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };

@@ -835,6 +836,6 @@
        execve("/sbin/init",argv_init,envp_init);
        execve("/etc/init",argv_init,envp_init);
        execve("/bin/init",argv_init,envp_init);
-       execve("/bin/sh",argv_init,envp_init);
+       execve("/bin/sh",argv_sh,envp_init);
        panic("No init found.  Try passing init= option to kernel.");
 }
