Re: [PATCH 3/3] Compare namespaces when comparing addresses in auth_unixcache.

[Rob Landley]

On 04/11/2011 08:57 AM, Alexey Dobriyan wrote:
> On Mon, Apr 11, 2011 at 4:36 PM, Serge E. Hallyn <serge@xxxxxxxxxx> wrote:
> 
>> Besides use-after-free, the other concern is an invalid net_eq()
>> result due to the * being re-used for a new netns.
> 
> Exactly.
> 
> "struct net" dies last, no exceptions, anything different is a disaster.

Actually the patch turns out to be irrelevant because Pavel made the
whole thing into a pernet subsystem, so it was already fixed in a
different way.  (Commit 2f72c9b7.  My bad, I initially started working
against an NFS tree with an older kernel version, this fix was to a
different source file so my patch still applied, and I just regression
tested that it worked, not that it still failed without it.  Just caught
it now.)

I actually did talk about addressing potential reuse of the net * in my
email with Stanislav (point of the patch was to allow one cache to
maintain two different contexts at the same time; a situation that
changed the meaning of an existing cache entry by requiring the old
context to go away didn't introduce any new problems that a single
context didn't already have due to DNAT, servers moving, administrators
changing credentials on the server).  But sort of a moot point now.

I believe the third patch can be dropped entirely.

Rob
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/