From: "Kasatkin, Dmitry" <dmitry.kasatkin@intel.com>
To: Peter Jones <pjones@redhat.com>
Cc: linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC 1/2] export unpack_to_rootfs
Date: Fri, 8 Feb 2013 10:30:43 +0200 [thread overview]
Message-ID: <CALLzPKZ5UJFRvEYL4C=XAExqnsvvv5zudD6tj_vOYs5ix1DbGQ@mail.gmail.com> (raw)
In-Reply-To: <CALLzPKYLqR-rXyf4FFQpo31tTNsKm1=gyfeVi==LPqV6qX8jSw@mail.gmail.com>
On Tue, Feb 5, 2013 at 7:16 PM, Kasatkin, Dmitry
<dmitry.kasatkin@intel.com> wrote:
> On Tue, Feb 5, 2013 at 6:48 PM, Peter Jones <pjones@redhat.com> wrote:
>> On Tue, Feb 05, 2013 at 02:34:49PM +0200, Dmitry Kasatkin wrote:
>>> Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
>>> ---
>>> init/do_mounts.h | 2 ++
>>> init/initramfs.c | 2 +-
>>> 2 files changed, 3 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/init/do_mounts.h b/init/do_mounts.h
>>> index f5b978a..11829eb 100644
>>> --- a/init/do_mounts.h
>>> +++ b/init/do_mounts.h
>>> @@ -74,3 +74,5 @@ void md_run_setup(void);
>>> static inline void md_run_setup(void) {}
>>>
>>> #endif
>>> +
>>> +char * __init unpack_to_rootfs(char *buf, unsigned len);
>>> diff --git a/init/initramfs.c b/init/initramfs.c
>>> index 84c6bf1..e32bc06 100644
>>> --- a/init/initramfs.c
>>> +++ b/init/initramfs.c
>>> @@ -421,7 +421,7 @@ static unsigned my_inptr; /* index of next byte to be processed in inbuf */
>>>
>>> #include <linux/decompress/generic.h>
>>>
>>> -static char * __init unpack_to_rootfs(char *buf, unsigned len)
>>> +char * __init unpack_to_rootfs(char *buf, unsigned len)
>>> {
>>> int written, res;
>>> decompress_fn decompress;
>>
>> Doing this unconditionally seems to be inviting rootkit authors to use a
>> new and shiny tool. I also don't think it's the best way to do this,
>> but I'll comment on the other patch to explain why.
>>
>
Just wanted to point out, that there is no chance for rootkits in
anyway because of this:
1) "rootkits" can have unpacking functionality inside, but if they are so lazy
2) unpack_to_rootfs() is not EXPORT_SYMBOLed.
3) and more over, unpack_to_rootfs() is "__init" and is freed before
main initramfs or rootfs init is executed.
- Dmitry
> Sorry for re-post, but answering from mobile was in HTML and it was blocked.
> Modifying an initramfs gives the same opportunity during boot only.
> But agreed, it might be the part of the primary source code. It was
> very to do it in this way to implement and test a solution.
>
> Thanks.
>
>> --
>> Peter
next prev parent reply other threads:[~2013-02-08 8:30 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-05 12:34 [RFC 0/2] initramfs with digital signature protection Dmitry Kasatkin
2013-02-05 12:34 ` [RFC 1/2] export unpack_to_rootfs Dmitry Kasatkin
2013-02-05 16:48 ` Peter Jones
2013-02-05 17:16 ` Kasatkin, Dmitry
2013-02-08 8:30 ` Kasatkin, Dmitry [this message]
2013-02-05 12:34 ` [RFC 2/2] initramfs with digital signature protection Dmitry Kasatkin
2013-02-05 18:03 ` Peter Jones
2013-02-05 20:08 ` Mimi Zohar
2013-02-05 22:03 ` Kasatkin, Dmitry
2013-02-05 18:19 ` Matthew Garrett
2013-02-05 18:30 ` Matthew Garrett
2013-02-05 18:34 ` Vivek Goyal
2013-02-05 21:55 ` Kasatkin, Dmitry
2013-04-05 13:50 ` Vivek Goyal
2013-04-08 19:43 ` Mimi Zohar
2013-04-08 20:09 ` Vivek Goyal
2013-04-08 20:17 ` Josh Boyer
2013-04-09 14:38 ` Vivek Goyal
2013-04-10 3:07 ` Mimi Zohar
2013-04-10 19:42 ` Vivek Goyal
2013-04-10 21:05 ` Mimi Zohar
2013-04-11 8:08 ` Dmitry Kasatkin
2013-04-11 14:52 ` Vivek Goyal
2013-04-12 11:54 ` Mimi Zohar
[not found] ` <CACE9dm-GZpjco8u6jNxLQpYA8LYSeoVjsyyRXVwxXHzjO-LvGw@mail.gmail.com>
2013-04-11 14:55 ` Vivek Goyal
2013-04-11 18:42 ` Dmitry Kasatkin
2013-04-11 21:13 ` Vivek Goyal
2013-04-12 12:03 ` Mimi Zohar
2013-02-05 20:36 ` Peter Jones
2013-02-05 22:09 ` Kasatkin, Dmitry
2013-02-06 5:04 ` H. Peter Anvin
2013-02-06 8:01 ` Kasatkin, Dmitry
2013-02-06 16:41 ` H. Peter Anvin
2013-02-08 9:16 ` Kasatkin, Dmitry
2013-02-08 15:49 ` H. Peter Anvin
2013-02-08 16:24 ` Kasatkin, Dmitry
2013-02-08 16:50 ` H. Peter Anvin
2013-02-07 17:05 ` Vivek Goyal
2013-02-08 8:34 ` Kasatkin, Dmitry
2013-02-08 13:27 ` Kasatkin, Dmitry
2013-02-11 21:59 ` Vivek Goyal
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