Re: [PATCH nf 1/3] netfilter: conntrack: fix crash on timeout object removal

[Pablo Neira Ayuso <pablo@netfilter.org>]

On Mon, Oct 05, 2015 at 11:08:57PM +0800, kbuild test robot wrote:
> Hi Pablo,
> 
[...]
> 
> sparse warnings: (new ones prefixed by >>)
> 
> >> net/netfilter/nf_conntrack_core.c:956:54: sparse: incorrect type in argument 2 (different address spaces)
>    net/netfilter/nf_conntrack_core.c:956:54:    expected struct ctnl_timeout *timeout
>    net/netfilter/nf_conntrack_core.c:956:54:    got struct ctnl_timeout [noderef] <asn:4>*timeout
>    net/netfilter/nf_conntrack_core.c:1463:9: sparse: incompatible types in comparison expression (different address spaces)
>    net/netfilter/nf_conntrack_core.c:1468:9: sparse: incompatible types in comparison expression (different address spaces)
>    net/netfilter/nf_conntrack_core.c:1744:9: sparse: incompatible types in comparison expression (different address spaces)
>    net/netfilter/nf_conntrack_core.c:1745:9: sparse: incompatible types in comparison expression (different address spaces)
> 
> vim +956 net/netfilter/nf_conntrack_core.c
[...]
>
> 60b5f8f7 Pablo Neira Ayuso       2012-03-23  955  	if (timeout_ext)
> 60b5f8f7 Pablo Neira Ayuso       2012-03-23 @956  		nf_ct_timeout_ext_add(ct, timeout_ext->timeout, GFP_ATOMIC);

Fixed here through before pushing out this patch:

        nf_ct_timeout_ext_add(ct, rcu_deference(timeout_ext->timeout), GFP_ATOMIC);

I can't see any sparse warning anymore with the change above.

Thanks!