Re: [nft PATCH] libnftables: Fix for multiple context instances

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Mon, Nov 20, 2017 at 01:37:26PM +0100, Pablo Neira Ayuso wrote:
> On Thu, Nov 16, 2017 at 08:10:24PM +0100, Phil Sutter wrote:
> > If a second context is created, the second call to nft_ctx_free() leads
> > to freeing invalid pointers in nft_exit(). Fix this by introducing a
> > reference counter so that neither nft_init() nor nft_exit() run more
> > than once in a row.
> > 
> > This reference counter has to be protected from parallel access. Do this
> > using a mutex in a way that once nft_init() returns, the first call to
> > that function running in parallel is guaranteed to be finished -
> > otherwise it could happen that things being initialized in one thread
> > are already accessed in another one.
> 
> I would prefer this table is placed into the context object, so they
> are not global anymore. So I would prefer we fix this the right way(tm).
> 
> Let me know your thoughts, thanks!

I don't think that's feasible: Looking at 'mark_tbl' for instance, this is
accessed from callbacks in 'mark_type', so we would have to make nft_ctx
accessible by all functions dealing with datatypes.

Cheers, Phil
--
To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Netfitler Users]     [LARTC]     [Bugtraq]     [Yosemite Forum]

  Powered by Linux