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Re: [bug #28446] No checks are made for unteminated strings in RPC messa
From: |
Carl Fredrik Hammar |
Subject: |
Re: [bug #28446] No checks are made for unteminated strings in RPC messages |
Date: |
Fri, 1 Jan 2010 22:36:35 +0100 |
User-agent: |
Mutt/1.5.20 (2009-06-14) |
Hi,
On Thu, Dec 31, 2009 at 04:12:21AM +0100, olafBuddenhagen@gmx.net wrote:
> On Wed, Dec 30, 2009 at 07:42:21PM +0000, Carl Fredrik Hammar wrote:
>
> > Strings in RPCs, such as the filename argument to a dir_lookup, are
> > not checked if they are terminated by '\0'. This could lead to the
> > server segfaulting if it tries to read the string.
> >
> > Making MIG check that strings are terminated seems like the proper
> > fix.
>
> AIUI, the first step would be implementing actual string support in MiG
> at all...
MIG seems to already have some awareness of strings, atleast the client
part uses a variant of strncpy() to copy the string into the message.
So it should be possible to generate code specifically for strings in
the server part as well.
> While this should probably be considered a todo item, in the present
> situation, if a server doesn't protect against non-terminated strings,
> it's a bug *in this server*. If you see any actual instances of this,
> could you report them?...
It is hard to be certain that a translator isn't vounerable unless it
has an explicit check, which I expect no translator currently have.
For instance, I extfs returns ENAMETOOLONG because it I tested with a
single component path, but it might be possible to get it to read past
the end using many components, e.g. `././././....', though I suspect
this will return ELOOP.
Fixing MIG seems much easier and safer.
Regards,
Fredrik
- Re: [bug #28446] No checks are made for unteminated strings in RPC messages, olafBuddenhagen, 2010/01/01
- Re: [bug #28446] No checks are made for unteminated strings in RPC messages, Samuel Thibault, 2010/01/01
- Re: [bug #28446] No checks are made for unteminated strings in RPC messages,
Carl Fredrik Hammar <=
- Re: [bug #28446] No checks are made for unteminated strings in RPC messages, olafBuddenhagen, 2010/01/02
- Re: [bug #28446] No checks are made for unteminated strings in RPC messages, Carl Fredrik Hammar, 2010/01/02
- Re: [bug #28446] No checks are made for unteminated strings in RPC messages, olafBuddenhagen, 2010/01/03
- Re: [bug #28446] No checks are made for unteminated strings in RPC messages, Carl Fredrik Hammar, 2010/01/03
- Re: [bug #28446] No checks are made for unteminated strings in RPC messages, olafBuddenhagen, 2010/01/06
- Re: [bug #28446] No checks are made for unteminated strings in RPC messages, Carl Fredrik Hammar, 2010/01/07
- Re: [bug #28446] No checks are made for unteminated strings in RPC messages, olafBuddenhagen, 2010/01/10